Shannon - I really appreciate the advice you have provided here! I have a 1997 Yamaha Wave Venture 760 GP with dual carbs. For 20 years it has amazed me at how incredibly dependable it has been. Yet, for the last 18 months it did not get used. Now, it would not start, and would only run a bit when primed with a bit of gas put in the fogging hole. I took on the adventure of rebuilding the carb with new gaskets and things. I found the pump diaphragm stiff and figured that was the problem. Once put back together it started right up, and the engine would rev up just fine on the trailer. But, once in the water, trying to rev up the engine - it bogged down badly. I found that if while idling, I pulled the choke out and then pushed it in while going to full throttle - I could get the engine up to speed and the ski running pretty fast. I have been puzzling about what the most likely reason for this is? I did not replace the needles, seats, arm or springs as they seemed perfectly fine (and i did not want to risk putting in a new spring that might be wrong). I also never messed with the low and high adjuster needles thinking i would just mess them up. I did completely clean out the gas tank and lines and they seem fine. What would be your best guess as to my problem? I have looked at sites that tell you how to adjust the low and high needles. It appeared the low speed adjustment is 1 & 5/8ths, +/- 1/4. I get that. I don't get the high speed one: the chart I have says -3/8ths +/- 1/4. If you turn the screw in until it is seated, wouldn't a minus 3/8ths mean to tighten it down by 3/8ths of a turn more shut? Thanks for any advice you can send my way!
The only way you want to mess with those adjustments as far as the low and high speed go is if somebody has mess with them and you check them by the book and they are way off you said the ski ran great for a long long time so do not mess with the high and low speed Jets that's not going to be your problem did you blow carburetor cleaner through the checks while they were installed and open the flat there are three tiny tiny holes in the throat of the carburetor that will be the little bitty Joe blow through that and make sure you can see the fuel blowing out there will be one bigger hole and three little tiny ones make sure those are open then you want to pressure up your fuel tank and make sure that it is holding fuel pressure you can do that with a compressor and you just put a nozzle on it put it to the main gas line make sure your gas valve is open and put some air in it until you see the tank slightly balloon then put your thumb over and just listen if you hear a tank valve leaking let the pleasure bleed down a bit because it's supposed to hold at about 7 lb check your gas cap lid to make sure the Rubber seal is good
@@shannonwilliams601 Yes! Thanks! I know my tank holds pressure as I have taken the lid off recently after the ski had been in the sun. The cap nearly popped off as i unscrewed it as the tank had warmed up and pressurized. I wonder: I am feeling pretty bad about using an after market kit to rebuild the carbs. There are many that warn against this. In my case, what if the new check valve little tear drop plastic thing near the high speed jet is thicker / stiffer than it is supposed to be. If so, it would not open unless it really got sucked open. i think this is a plausible explanation for why the ski idles well, and if coaxed with the choke -> can get to high speed and run. In the middle, maybe there is not enough easy flow through that check valve? In any case, it looks like i need to redo my rebuild anyway and double check those passage ways you mentioned. I may get genuine Mikuni parts and change out the check valve plastic things too.
I thought I could use my mityvac silverline hand vacuum/pressure pump but it only shows vacuum on the gauge. Your video is one of the better one's I've seen so far. You did say the gauge was at 10psi when obviously it was at 20.
Hello, very interesting video. I have 2 Mikuni 38 carbs on my Kawa jet ski. I changed nozzles and gaskets, cleaned everything.... I put transparent hoses to see the fuel. Problem after filling the hoses with a syringe, the engine runs but the gasoline does not arrive (see the little that remains tends to go back to the tank (no suction to the carbs)? I connected the fuel correctly carburetor according to the plan (intake, return, low engine pump)? I tested the pressure for opening nozzle 19 psi THANKS A LOT
I'm not sure what you're referring to as a nozzle are you talking about the needle and seat and you also have to do a fuel pressure check on your fuel system to make sure it's holding to get fuel back to the motor
Thanks for the video, it's very helpful. I have a question regarding pop off pressure. I followed your vid step for step but noticed my needle would leak slightly right at pop off pressure. I never could get my needle to pop like yours as you pumped your test meter assembly. However for my test assembly I used my air compressor and placed a inline regulator set to 60 lbs followed by a needle valve to control the flow. Could my test assembly needle valve restrict the pressure to the needle and seat valve so that it opens gradually instead of popping it open? Thanks for any advice you can offer.
you just described what is happening to my seadoo engine...hard too start and dies on idle. At first I thought it was a electrical issue...I'm not a gear head but I'm gonna try to rebuild the carb myself...thanks.
Also go on amazon and get a JIS “Japanese industrial standard” Philips screw driver for those mikuni screws that ALWAYS “cam out” or “strip”. A good brand is Vessel that’s the one I got and no more stripped carb screws
HEY SHANNON! I have a 1996 Yamaha Wave Raider 1100! Useully runs great! But it stalled twice on me out there....installed new Start/Stop Switch Box & new Starter Solenoid! When I jump the Solenoid terminals it cranks over fine! Nothing when I hit the Green Start Button!!! There in No Power to the White Start/Stop Connector comming from the CDI Box!!! Any idea's?
What you want to do is unplug the starter switch from the solenoid and check the ohms reading there if it's not reading the correct ohms undo the handlebar switch and there is a small computer board up on the handlebars left side make sure it's good and clean the connections get dirty and it does it communicate
The 1st thing I did when I got it back home was disconnected battery then install a new start stop switch and plug it in and then a new starter cell annoyed and plug that and My problem is I have no power coming out of the white CDI box to the start stop switch on the white connector! I need to try to figure out where it's losing power?
I bought this ski last year tuned it all up and ran it like a bad out of hell all day brought it home winterized it then this summer took it out again And it run as usual like a bad out of hell however it did stall 2 times on me and I lost the green start button so It would not start anymore . I got towed into the dock, brought it home took it apart put a new start stop box in and a new solenoid! Still no crank, atill no power to the white start/ atop wire that goes uo to the Start Button! I just made an appointment to bring it to Phils jet ski in Stuart Florida for him to try to figure out because I don't think that this is a DIY project anymore!
And yes it has a digital - that does not work'! There is some type of jumper wire on the digital - but the ski ran fine Before so I'm not sure that has anything to do with it!
Thanks much man.Very informative. Id like to see more vids on these mikunic carb..If you want id really like to see a vid on the carb adjustment .I have a similar set up.Thanks again dude..
Can I ask a question.. if you replace the spring from let’s say a 42 grams to a 48 grams, what’s the effect of doing that? Will it let less flue in? I replaced the spring on my Tillotson carburetor from a 42 grams to a 46 grams and the engine has a better response coming out of the corners, with the 42 grams the engine would just die, too much fuel I think, now with the 46 grams the engine really takes off coming out of the corners, but there is still a slight of too much fuel in one corner of the track, so I’m considering replacing the 46 grams for a 48 grams, don’t know if that would be too much pressure?
If you change the spring it's going to change the pressure it takes to open the needle but when it opens it's going to let the same amount of fluid in that doesn't change because the seat stays the same you want the Popoff pressure to be whatever it says in the book for your year make and model
Hi, on the spring side of the lever where should it be in relation to ? in a starting position? because if you bend the lever it changes the height of the lever to the diaphragm pin
I've got a 99 seadoo XP that is all stock but recently acquired a R&D Power Plenum. Not sure what the high and lows should be adjusted to on the carb. Ran it after the install and it acts like it Boggs down unless I give it full throttle and after some hesitation finally starts going. Full throttle it's good. Any help would be appreciated.😊
So did this come off of a 657x rotax? And this will cause a hard start condition? I have a 1995 seadoo speedster that I bought last summer and it always seems like the left motor has trouble starting period. Do you think it is worth checking this first? or doing a complete rebuild on the carbs?
That's probably going to be a fuel pressure problem you need to pressure up your fuel system and make sure your tank is holding at least 5 to 7 lb it's going to be that or a weak fuel pump diaphragm also check your fire and your spark plugs make sure all is good
Check your fuel pressure in your gas tank make sure it is holding at 5 to 7 lb check your spark plugs and make sure your diaphragm in your fuel pump is not weak
@@arkansasoutdoorsmen5433 it should not cause both Motors to do it those are independent Motors and drive shafts check the compression on the motor and make sure it's between 1:30 and 1:50 and it's within 10% of each other because of the compression is low it will be hard to start and as it goes lower it won't start at all
I'm working on some sbn44s with a 1.5 needle and seat, 95g dull silver spring, 120 main and 110 pilot jet, plugged into the pulse line on the bottom (where the fuel pump check valves are) and plugged up the other lines. I'm supposed to be getting 42psi or so but I get it to 30psi then it opens up slowly and lets air out down to 15psi over 5 seconds or so. I'm using various bits and bobs to plug the other lines but I don't think that's the problem
It sounds like an air leak actually, the wd40 isn't foaming at all. I don't have my t handle high and low adjustment screws in yet, shipped but not here. That could be it.
Don't know what happened but now it goes up to 50psi easily, not going to go higher because I don't want to damage it. It lets out pressure at 50 and sits at 40 for a second or so then drops down to 28
Try using a higher tension spring to achieve the pressure you are looking for and always especially if you're working on a Yamaha spray around the fuel pump diaphragm area block with soapy water because the pressure is so great that they tend to leak if this becomes a problem take some form a gasket and just brush around the edges of the diaphragm and put the fuel pump back together the black rubber diaphragm is the one I am referring to to achieve the pressure for Yamahas
Don Rown yes take the main gas line off and u air pressure to push the fuel back until you see the tank start to air up then stop and see if you can hear a leak .open gas cap to release
I have a 1995 kawasaki jet ski, on a cold start I have to prime the carb & it starts right up, when she is warmed up i don't have to prime the carb. it starts right up. Can you tell me whats goin on here & where to look for the problem. Thank You!
I had ended up using a mechanical pencil spring for my twin carbs, provides the proper tension, and havent had a problem with it. Bare in mind this was for my 96 spx. 38-60 psi spec.
@@manstersr was a Bic Pencil I believe. Worked great. I eventually swapped my twin carb for a single one because of a variety of reasons but I ran two of those springs (one in each carb) and it had no issues over a season.
I need help with my wavrunner. It has 2 of these and will idle in water but dies when gas is applied. What did I do wrong. Rebuilt both carbs both with new seat needles and springs.
Take your main gas line off of the carburetor and pressure it up with a compressor until you see the tank start to balloon just a little then hold your thumb over the line as you listen for a leak you must be able to hold 7 to 8 lb of pressure in your gas tank for it to run right check your gas cap seal and your tank pressure seal to make sure that it's holding
Ok so tank should be pressurized? I have 4 lines coming out of the tank/sending unit. 2 lines run to the gas intake on both carbs. The other is a vent line with one way valve and other was for res on the switch but I bypassed the turn off switch so I just capped the last line.
@@pittsburghhustler412 there's no reason to bypass your fuel valve and on that set of lines your vent will be across from your return and you're on will be across from your reserve
Ok so there are 2 lines that run to the carbs. Both carbs are connected together with hoses and there is a t where the lines connect. One is on top one is on the bottom. Which is the return? Top or bottom? And I bypassed the switch because the knob broke off and was stuck to the off position. Should I buy a new one and go back to factory line routes? Only thing that is unhooked and plugged is the reserve line.
@@pittsburghhustler412 order a new fuel selector valve from SVT and take your one-way check valve off of the tank and make sure that you can only blow through it one way to see if it's good then do a pressure check
I've got an issue with a similar set of carbs on a yamaha 95 wave raider. I get it on the water and go full throttle but as soon as I let off the throttle and go back to idle it gets sputtery and will never go full throttle again. Any ideas?
@@shannonwilliams601 thanks for replying to such an old video. I was looking at buying an ultra 150 with similar carbs. Is that a reliable ski for an older one?
@@IcedOmega13 those are okay skis but I would not call them reliable they had oil problems and also the timing that makes them so fast also makes them vulnerable to fail if you want a reliable 2-stroke jet ski you buy a Yamaha and don't buy anything no matter what brand that says d i which stands for direct inject no brand was successful on the d i
It can only leak on the fuel pump side pour on the needle and seat so pressure it up spray WD-40 find the leak and just seal it off if it's the needle and seat leaking you might need a new one
So, these carbs require massive fuel pump pressure to run, eh? Good to know 'cuz I just ran into a Tigershark 900 with this carb type and was trying to start it using conventional fuel pump pressure from a primer bulb.
If you don't check your fuel system for the right pressure you will blow the Rings out of your motor fuel pressure is very important if the tank is not holding the right amount of pressure from the engine case it will create a lean condition and when it does you will need a new top-end in your engine make sure you check your fuel pressure on every aspect of that ski
I have a gp1200r It stall or bog down from 1/2 throttle to full. It goes around 30-45mph at 1/2 throttle. Also when i give it full gas it launches then bogs down. Do i need to check the pop off? It starts right up every time. Also was told it had bigget jets, d plate, velocity stacks, I moved the high speed needle to 1 1/2 (under the carb, bottom needle) Also the high speed have the same, runs better than the first time but still bogs down. Took the carbs appart to check the filter and all the parts looks in good condition, nothing ripped. Any help?
what u need to do is set both hi and low at the stock settings then put it in the water then start with the low end after the ski warms up punch it if it falls on it face then turn your low 1/4 turn then idle around for a min or so to let your carb take the new setting then punch it if it still falls go back to stock and go 1/4 the other way whatever way it runs better keep working it 1/4 turn at a time be careful not to lean it out
yes it's possible, if the pop off pressure was too high and it was not able to get enough fuel, that could cause an RPM increase at idle followed by stalling when you gave it any gas
Geez... it quit bubbling when you let all the pressure off! It shouldnt bubble after the 10 psi drop from pop off. you have a defective needle or seat o-ring.. You should alway test at least 3 times to get an average.
Actually you can been the tab down a little bit if it's not running perfectly parallel I've been working on watercrafts for over 20 years trust me I know
@@Hello-pu6uv not true at all you can get one from Mikuni or aftermarket and sometimes they will not be parallel it will work either way but if you're not getting the correct pop off you can been that little tab down until it's parallel even the parts kit instructions tell you that so you're right to each his own I've repaired about 5,000 jet skis how many have you repaired
![OhGeesy x Lefty Gunplay - What It Iz [Official Music Video]](http://i.ytimg.com/vi/L0yzW9t2ixk/mqdefault.jpg)
Shannon - I really appreciate the advice you have provided here! I have a 1997 Yamaha Wave Venture 760 GP with dual carbs. For 20 years it has amazed me at how incredibly dependable it has been. Yet, for the last 18 months it did not get used. Now, it would not start, and would only run a bit when primed with a bit of gas put in the fogging hole. I took on the adventure of rebuilding the carb with new gaskets and things. I found the pump diaphragm stiff and figured that was the problem. Once put back together it started right up, and the engine would rev up just fine on the trailer. But, once in the water, trying to rev up the engine - it bogged down badly. I found that if while idling, I pulled the choke out and then pushed it in while going to full throttle - I could get the engine up to speed and the ski running pretty fast.
I have been puzzling about what the most likely reason for this is? I did not replace the needles, seats, arm or springs as they seemed perfectly fine (and i did not want to risk putting in a new spring that might be wrong). I also never messed with the low and high adjuster needles thinking i would just mess them up. I did completely clean out the gas tank and lines and they seem fine. What would be your best guess as to my problem? I have looked at sites that tell you how to adjust the low and high needles. It appeared the low speed adjustment is 1 & 5/8ths, +/- 1/4. I get that. I don't get the high speed one: the chart I have says -3/8ths +/- 1/4. If you turn the screw in until it is seated, wouldn't a minus 3/8ths mean to tighten it down by 3/8ths of a turn more shut? Thanks for any advice you can send my way!
The only way you want to mess with those adjustments as far as the low and high speed go is if somebody has mess with them and you check them by the book and they are way off you said the ski ran great for a long long time so do not mess with the high and low speed Jets that's not going to be your problem did you blow carburetor cleaner through the checks while they were installed and open the flat there are three tiny tiny holes in the throat of the carburetor that will be the little bitty Joe blow through that and make sure you can see the fuel blowing out there will be one bigger hole and three little tiny ones make sure those are open then you want to pressure up your fuel tank and make sure that it is holding fuel pressure you can do that with a compressor and you just put a nozzle on it put it to the main gas line make sure your gas valve is open and put some air in it until you see the tank slightly balloon then put your thumb over and just listen if you hear a tank valve leaking let the pleasure bleed down a bit because it's supposed to hold at about 7 lb check your gas cap lid to make sure the Rubber seal is good
Let me know if you got my message
@@shannonwilliams601 Yes! Thanks! I know my tank holds pressure as I have taken the lid off recently after the ski had been in the sun. The cap nearly popped off as i unscrewed it as the tank had warmed up and pressurized.
I wonder: I am feeling pretty bad about using an after market kit to rebuild the carbs. There are many that warn against this. In my case, what if the new check valve little tear drop plastic thing near the high speed jet is thicker / stiffer than it is supposed to be. If so, it would not open unless it really got sucked open. i think this is a plausible explanation for why the ski idles well, and if coaxed with the choke -> can get to high speed and run. In the middle, maybe there is not enough easy flow through that check valve? In any case, it looks like i need to redo my rebuild anyway and double check those passage ways you mentioned. I may get genuine Mikuni parts and change out the check valve plastic things too.
@@stevegerrity5296 you do not have to buy genuine Mikuni you can go to SBT we buy those all the time and they're very good kits
Where did you get your carburetor kits that you used
I thought I could use my mityvac silverline hand vacuum/pressure pump but it only shows vacuum on the gauge. Your video is one of the better one's I've seen so far. You did say the gauge was at 10psi when obviously it was at 20.
Well only a few of us are perfect in the world and I guess I'm not one of them but it sounds like you are thanks for noticing
Very helpful and very knowledgeable thanks for the step by step instructions and thorough. Thanks for the help!
Hello, very interesting video. I have 2 Mikuni 38 carbs on my Kawa jet ski. I changed nozzles and gaskets, cleaned everything.... I put transparent hoses to see the fuel. Problem after filling the hoses with a syringe, the engine runs but the gasoline does not arrive (see the little that remains tends to go back to the tank (no suction to the carbs)? I connected the fuel correctly carburetor according to the plan (intake, return, low engine pump)? I tested the pressure for opening nozzle 19 psi
THANKS A LOT
I'm not sure what you're referring to as a nozzle are you talking about the needle and seat and you also have to do a fuel pressure check on your fuel system to make sure it's holding to get fuel back to the motor
@@shannonwilliams601 Thank you
I change the motorcycle jet and hall gasquets. I try to put on the fuel bottle all the hoses ....
Thanks for the video, it's very helpful. I have a question regarding pop off pressure. I followed your vid step for step but noticed my needle would leak slightly right at pop off pressure. I never could get my needle to pop like yours as you pumped your test meter assembly. However for my test assembly I used my air compressor and placed a inline regulator set to 60 lbs followed by a needle valve to control the flow. Could my test assembly needle valve restrict the pressure to the needle and seat valve so that it opens gradually instead of popping it open? Thanks for any advice you can offer.
only one of my cilyinders is flooding to a point of cease firing could it still be popoff? seadoo 717 single carb
Probably a bad needle and Seat
@@shannonwilliams601 thank you sir i will be checking that out.
I learned about pop off pressure today. Thanks!!
you just described what is happening to my seadoo engine...hard too start and dies on idle. At first I thought it was a electrical issue...I'm not a gear head but I'm gonna try to rebuild the carb myself...thanks.
Also go on amazon and get a JIS “Japanese industrial standard” Philips screw driver for those mikuni screws that ALWAYS “cam out” or “strip”. A good brand is Vessel that’s the one I got and no more stripped carb screws
HEY SHANNON! I have a 1996 Yamaha Wave Raider 1100! Useully runs great! But it stalled twice on me out there....installed new Start/Stop Switch Box & new Starter Solenoid! When I jump the Solenoid terminals it cranks over fine! Nothing when I hit the Green Start Button!!! There in No Power to the White Start/Stop Connector comming from the CDI Box!!!
Any idea's?
What you want to do is unplug the starter switch from the solenoid and check the ohms reading there if it's not reading the correct ohms undo the handlebar switch and there is a small computer board up on the handlebars left side make sure it's good and clean the connections get dirty and it does it communicate
The 1st thing I did when I got it back home was disconnected battery then install a new start stop switch and plug it in and then a new starter cell annoyed and plug that and My problem is I have no power coming out of the white CDI box to the start stop switch on the white connector! I need to try to figure out where it's losing power?
Did you just get this jet ski and does it have a digital dash
I bought this ski last year tuned it all up and ran it like a bad out of hell all day brought it home winterized it then this summer took it out again And it run as usual like a bad out of hell however it did stall 2 times on me and I lost the green start button so It would not start anymore . I got towed into the dock, brought it home took it apart put a new start stop box in and a new solenoid! Still no crank, atill no power to the white start/ atop wire that goes uo to the Start Button! I just made an appointment to bring it to Phils jet ski in Stuart Florida for him to try to figure out because I don't think that this is a DIY project anymore!
And yes it has a digital - that does not work'! There is some type of jumper wire on the digital - but the ski ran fine Before so I'm not sure that has anything to do with it!
When you clean a carburetor can you just put the original pop offspring back on?
Yes but you still have to check the pop off pressure to see if your needle and seat is leaking or anything else
Thanks much man.Very informative. Id like to see more vids on these mikunic carb..If you want id really like to see a vid on the carb adjustment .I have a similar set up.Thanks again dude..
I can tell u how to set your low and high end carb setting let me know what u need to know
What are you using to pump up the pressure? Some sort of hand pump?
Sbt finger pump
Can I ask a question.. if you replace the spring from let’s say a 42 grams to a 48 grams, what’s the effect of doing that? Will it let less flue in?
I replaced the spring on my Tillotson carburetor from a 42 grams to a 46 grams and the engine has a better response coming out of the corners, with the 42 grams the engine would just die, too much fuel I think, now with the 46 grams the engine really takes off coming out of the corners, but there is still a slight of too much fuel in one corner of the track, so I’m considering replacing the 46 grams for a 48 grams, don’t know if that would be too much pressure?
If you change the spring it's going to change the pressure it takes to open the needle but when it opens it's going to let the same amount of fluid in that doesn't change because the seat stays the same you want the Popoff pressure to be whatever it says in the book for your year make and model
@@shannonwilliams601
Thanks 🙏
Excelent tutorial...
Hi, on the spring side of the lever where should it be in relation to ? in a starting position? because if you bend the lever it changes the height of the lever to the diaphragm pin
Don't bend the lever it should be parallel
I've got a 99 seadoo XP that is all stock but recently acquired a R&D Power Plenum. Not sure what the high and lows should be adjusted to on the carb. Ran it after the install and it acts like it Boggs down unless I give it full throttle and after some hesitation finally starts going. Full throttle it's good. Any help would be appreciated.😊
jarod matheson it's in your low end so a reset your low end
What company sells the needle & seat?? I didnt understand what he said
Sbt.com
What if the pressure doesn't drop after pop? I get to 30/31 psi and it's pops off, and then stops at 30psi. Doesn't move from there.
So did this come off of a 657x rotax? And this will cause a hard start condition? I have a 1995 seadoo speedster that I bought last summer and it always seems like the left motor has trouble starting period. Do you think it is worth checking this first? or doing a complete rebuild on the carbs?
That's probably going to be a fuel pressure problem you need to pressure up your fuel system and make sure your tank is holding at least 5 to 7 lb it's going to be that or a weak fuel pump diaphragm also check your fire and your spark plugs make sure all is good
Check your fuel pressure in your gas tank make sure it is holding at 5 to 7 lb check your spark plugs and make sure your diaphragm in your fuel pump is not weak
Shannon Williams wouldn’t that cause both motors to do that? It’s a twin motor jet boat. Spark is good. Any other ideas?
@@arkansasoutdoorsmen5433 it should not cause both Motors to do it those are independent Motors and drive shafts check the compression on the motor and make sure it's between 1:30 and 1:50 and it's within 10% of each other because of the compression is low it will be hard to start and as it goes lower it won't start at all
Very Good Tutorial thanks for explaing
I'm working on some sbn44s with a 1.5 needle and seat, 95g dull silver spring, 120 main and 110 pilot jet, plugged into the pulse line on the bottom (where the fuel pump check valves are) and plugged up the other lines. I'm supposed to be getting 42psi or so but I get it to 30psi then it opens up slowly and lets air out down to 15psi over 5 seconds or so. I'm using various bits and bobs to plug the other lines but I don't think that's the problem
It sounds like an air leak actually, the wd40 isn't foaming at all. I don't have my t handle high and low adjustment screws in yet, shipped but not here. That could be it.
Don't know what happened but now it goes up to 50psi easily, not going to go higher because I don't want to damage it. It lets out pressure at 50 and sits at 40 for a second or so then drops down to 28
Try using a higher tension spring to achieve the pressure you are looking for and always especially if you're working on a Yamaha spray around the fuel pump diaphragm area block with soapy water because the pressure is so great that they tend to leak if this becomes a problem take some form a gasket and just brush around the edges of the diaphragm and put the fuel pump back together the black rubber diaphragm is the one I am referring to to achieve the pressure for Yamahas
great vid, good info.
where did you buy the pop off tool?
Sbt.. or wsm
Thanks, found a 60 psi one on Amazon. My pressure spec is 38.2 +- 12 so those 30 psi ones I am seeing won't do it.
I have a 787 rotax is there a way to check fuel pressure coming to the carb? Thanks
Don Rown yes take the main gas line off and u air pressure to push the fuel back until you see the tank start to air up then stop and see if you can hear a leak .open gas cap to release
so if it is too high i cut the spring?
That's only if you're limited on your Springs if you have a lower pressure spring I would recommend using that over clipping ones
What did you use to hold in the pressure(Red plastic)
Just a rubber plug and a zip tie
Where did you buy the pressure gauge?
how much
sbt.com
should be shopsbt.com
I have a 1995 kawasaki jet ski, on a cold start I have to prime the carb & it starts right up, when she is warmed up i don't have to prime the carb. it starts right up. Can you tell me whats goin on here & where to look for the problem. Thank You!
HAWKEYE-1 what motor does it have
Not sure of size but it,s a 2 stroke w 2-cyl.
Mine does the same. Kawasakis of that age are notorious for that problem. Add a primer kit to it and all will be fine. Check ebay
That sounds normal
HAWKEYE-1 is it the 3 cycenlender
I had ended up using a mechanical pencil spring for my twin carbs, provides the proper tension, and havent had a problem with it. Bare in mind this was for my 96 spx. 38-60 psi spec.
You just got lucky that that spring had the right tension
What kind of pencil? Brand and name?
@@manstersr was a Bic Pencil I believe. Worked great. I eventually swapped my twin carb for a single one because of a variety of reasons but I ran two of those springs (one in each carb) and it had no issues over a season.
I need help with my wavrunner. It has 2 of these and will idle in water but dies when gas is applied. What did I do wrong. Rebuilt both carbs both with new seat needles and springs.
Take your main gas line off of the carburetor and pressure it up with a compressor until you see the tank start to balloon just a little then hold your thumb over the line as you listen for a leak you must be able to hold 7 to 8 lb of pressure in your gas tank for it to run right check your gas cap seal and your tank pressure seal to make sure that it's holding
Ok so tank should be pressurized? I have 4 lines coming out of the tank/sending unit. 2 lines run to the gas intake on both carbs. The other is a vent line with one way valve and other was for res on the switch but I bypassed the turn off switch so I just capped the last line.
@@pittsburghhustler412 there's no reason to bypass your fuel valve and on that set of lines your vent will be across from your return and you're on will be across from your reserve
Ok so there are 2 lines that run to the carbs. Both carbs are connected together with hoses and there is a t where the lines connect. One is on top one is on the bottom. Which is the return? Top or bottom? And I bypassed the switch because the knob broke off and was stuck to the off position. Should I buy a new one and go back to factory line routes? Only thing that is unhooked and plugged is the reserve line.
@@pittsburghhustler412 order a new fuel selector valve from SVT and take your one-way check valve off of the tank and make sure that you can only blow through it one way to see if it's good then do a pressure check
Excellent!
I've got an issue with a similar set of carbs on a yamaha 95 wave raider. I get it on the water and go full throttle but as soon as I let off the throttle and go back to idle it gets sputtery and will never go full throttle again. Any ideas?
Check your fuel pressure and also check your pop off pressure
@@shannonwilliams601 thanks for replying to such an old video. I was looking at buying an ultra 150 with similar carbs. Is that a reliable ski for an older one?
If you want a really reliable ski you want to go with a Yamaha
And don't buy anything that says d i on it no matter what brand it is
@@IcedOmega13 those are okay skis but I would not call them reliable they had oil problems and also the timing that makes them so fast also makes them vulnerable to fail if you want a reliable 2-stroke jet ski you buy a Yamaha and don't buy anything no matter what brand that says d i which stands for direct inject no brand was successful on the d i
What happens if I doesn’t hold the pressure and leaking somewhere
It can only leak on the fuel pump side pour on the needle and seat so pressure it up spray WD-40 find the leak and just seal it off if it's the needle and seat leaking you might need a new one
You can always tell the main gas line because it comes right into the fuel pump on the side of the carburetor
So, these carbs require massive fuel pump pressure to run, eh? Good to know 'cuz I just ran into a Tigershark 900 with this carb type and was trying to start it using conventional fuel pump pressure from a primer bulb.
If you don't check your fuel system for the right pressure you will blow the Rings out of your motor fuel pressure is very important if the tank is not holding the right amount of pressure from the engine case it will create a lean condition and when it does you will need a new top-end in your engine make sure you check your fuel pressure on every aspect of that ski
I just read from Chris from Watercraft Magic never to clip a spring but only adjust by bending the arm up to 1mm or get a new spring
And I guess Chris is a super know it all opinions are like assholes everybody has one you're welcome to do it anyway you see fit
@@shannonwilliams601 wow cant take criticism but you sure can go comment on other people trying to give instructions on other videos
Very helpful
Sure is a good video.
Very good info
I have a gp1200r
It stall or bog down from 1/2 throttle to full. It goes around 30-45mph at 1/2 throttle. Also when i give it full gas it launches then bogs down. Do i need to check the pop off? It starts right up every time. Also was told it had bigget jets, d plate, velocity stacks,
I moved the high speed needle to 1 1/2 (under the carb, bottom needle)
Also the high speed have the same, runs better than the first time but still bogs down.
Took the carbs appart to check the filter and all the parts looks in good condition, nothing ripped.
Any help?
Oswaldo Castillo sounds like you need to rebuild your carbs also do a fuel pressure test on your tank and lines
Shannon Williams so it needs a rebuilt no matter if the parts looks good and clean? Ill check that too and pop off just to be sure
👍
Thank you v mush
what u need to do is set both hi and low at the stock settings then put it in the water then start with the low end after the ski warms up punch it if it falls on it face then turn your low 1/4 turn then idle around for a min or so to let your carb take the new setting then punch it if it still falls go back to stock and go 1/4 the other way whatever way it runs better keep working it 1/4 turn at a time be careful not to lean it out
We have a 91 single car 650 watch the pressure on that I can't find it anywhere
would this make the engine rev out at idle??
yes it's possible, if the pop off pressure was too high and it was not able to get enough fuel, that could cause an RPM increase at idle followed by stalling when you gave it any gas
Geez... it quit bubbling when you let all the pressure off! It shouldnt bubble after the 10 psi drop from pop off. you have a defective needle or seat o-ring.. You should alway test at least 3 times to get an average.
Yes definitely
Replace the spring for proper pop off pressure, don't bend the arm
Actually you can been the tab down a little bit if it's not running perfectly parallel I've been working on watercrafts for over 20 years trust me I know
To each they're own but, if it wasn't somehow bent by accident, it shouldn't need to be bent and it's covering up the actual issues
@@Hello-pu6uv not true at all you can get one from Mikuni or aftermarket and sometimes they will not be parallel it will work either way but if you're not getting the correct pop off you can been that little tab down until it's parallel even the parts kit instructions tell you that so you're right to each his own I've repaired about 5,000 jet skis how many have you repaired
what if doesn't pop?
what could be wrong..
R Zarat to strong of a spring
a pump works better