Yamaha updated the power valve design in 2001 so that the valve doesn’t get as close to the piston. Previous to 2001 the saddle in the jug is supposed to hold the valve back from the piston but as the valve and jug wears, it gets closer. I have a pdf about the change. The old power valve part numbers end in 02, and the updated ones end in 03.
2001 and just finished a repair for the power valve tooth striking the piston. I'd question that they changed anything, because even now that it's reset it still sits very close
@@TheTyphoon365 Those clearances are close for sure. This one I build is srarting and running very well. I know some people hate the yamaha power valve engines. I am enjoying working on them. The GP1300R valves sure look sleeker than these. I hope your build goes well.
@@ShadetreeJetski going well so far, heads back on. Just need to maybe open up the little pv electric motor & double check that. Also waiting on waveeater clips in the mail.
Great video Brother the power valves in the GP 1300 r make it mu6ch less reliable than the 1200.. I've had 1200s at my shop woth north of 1000hrs and still running strong 💪
Every owner's manual should have the top maintenance items. Instead, the waverunner manual dedicates a full chapter on how to boat and another on labels.
When you're putting the power valves in always remember to not use the factory pins and clips that hold them in always upgrade to the lever links and this will not happen
I used waveeater clips. I am guessing you are talking about the ones like sbt puts on their engines where the entire link encapsulates the end of the power valve.
How can a bad motor cause contact with the power valve and piston? The power valve only goes so far down. I replaced a power valve and piston from sbt this summer. Probably 8 hours later i lost that same power valve. Not sure what happened but i just got another piston and power valve. I cant find where the old one went.
Simple answer is clearance tolerances. I have had two factory yamaha xl800 cylinders, the rear ones, powervalves hit the cylinder. Sometimes the pin drops out of the powervalve and it hits the cylinder, or the pin itself drops and ruins the cylinder. Heat expansion of the metal sometimes causes the piston to hit the powevalve even if the motor for the valves is good. Now if you have a rebuilt cylinder and it is oversized and uses an oversized piston YOU MUST SHAVE THE POWERVALVES TO ACCOMMODATE THE NEW SIZING. If you dont then you get the results you experienced. SBT is well known for doing CRAP machine work. It is a fact you can read on any PWC forum. Sloppy cylinder boring and sleeve fitting. I WILL NOT use any SBT cylinders. I will buy parts from them but never ever anything they did the machine work on. So you may end up with the same results and if you cant find bits of metal you know are missing, you better tear down the entire engine and find them before you waste another 500 on parts. Guaranteed metal shavings are down in the bottom end of your engine.
On my gp800 I removed the power valves and cleaned all the carbon build up. There was a lot of greasy black sludge in the power valve compartment. Is this normal? Do you have to put grease in that compartment when reinstalling the power valve? Also noticed that new power valves come with 4 oil seals/grommets. I didn’t see any seals when I removed the old power valves. I can’t find any information on where these seals go or if they are required on the gp800. Any help would be greatly appreciated. Thanks
Those tiny seals go in the cylinder/jug where the shaft that slides through the powervalve sticks outside the cylinders. I lubed mine up with marine grease when I build them.
Just google gp800 power valve gasket kit. You'll need to replace the gasket for the cover anyway most likely. You'll get the seals and gasket for pretty cheap all in one. Just did mine last night.
I guess so. I suppose how well you tune the carbs will affect the amount of buildup as well. Keeping them clean is part of routine maintenance which most people arent going to do as it involves taking parts off the engine.
@@ShadetreeJetski ok got them out I’m doing a top end on a gp800 I’m wondering when all this stuff is back together how I set the timing for the power valves?
On my most recent lake outing, applying any throttle position and my 2001 XL800 would slowly accelerate from idle to 5000 rpm and it would get stuck at 5000 rpm for a few seconds before it would all the sudden wake up and accelerate at a normal pace to top speed of 52mph. It will run fine if I keep it above 5000 rpm. It ran like that for a while before I took it out of the water. It would start up fine and the engine would rev good to above 5000 rpm when it’s out of the water. I noticed that the power valve servo motor isn’t working and confirmed it by testing it per service manual when I got it home. I can turn the pulley by hand on top of the servo motor to move the cables, so maybe the power valves are not stuck? Would it be a bad idea to simply run the wave runner with the Power Valve Servo Motor disconnected and manually turn the servo pulley part ways and get some low-end power back? Or would I do more damage? I don't really know enough about this, but I seem to recall reading someone on pwcforum saying that doing so would work.
I have read the same thing. You physically wire tie the powervalves open but you will have no low end power. Personally I would NOT continue to run the engine this way as it will probably build up a lot of carbon deposits from the low end bog and further cause deposits on the powervalves. I would find a used motor at least and replace it so the engine functions as it should.
Oh and yes if you can move the cable wheel by hand the powervalves are not stuck, but if you dont have an SBT built engine or waveeater clips, you are still risking those steel pins dropping out into your cylinder and destroying it.
@@ShadetreeJetski Yeah, I think you are right. I’m currently searching for a used YPVS servo motor on ebay. I’m having a hard time finding anyone here in north Georgia that is willing to work on an old 2 stroke machine. The one local shop here charged me $1200 to rebuild the carbs couple month ago, when my 800XL stopped running. It ran fine again after the carb rebuilt for a few lake outings and now this issue with the YPVS. Thank you for posting these helpful videos.
@@ShadetreeJetski Wow, it's a small world. I live near Lake Lanier. Actually not too far away from you. I was shocked when that shop charged me $1200 just for the carb rebuild. I think they knew they could charge as much as they want, due to lack of competition. I'm trying to see if I can repair it myself now, since I can't afford to take it back to them for anymore repairs.
I bought my 2000 xl1200 from a guy that did no maint whatsoever can't stand people like that🤣had to remove all the powervalves and clean them all the shaft couplers were broken took alot of wd40 and carb cleaner. Replaced everything,deleted the cat that had fell apart it runs like a scalded dog now👍
I tested mine and a used one I bought with the jet ski itself. Just plug it in. I am sure there is a way to bench test it but I dont have a schematic. If the motor doesnt actuate back and forth 5 seconds after pressing the start button it probably is bad.
![Digital Circus Episode 4 [TRAILER]](http://i.ytimg.com/vi/abZtsmMUbJo/mqdefault.jpg)
Yamaha updated the power valve design in 2001 so that the valve doesn’t get as close to the piston. Previous to 2001 the saddle in the jug is supposed to hold the valve back from the piston but as the valve and jug wears, it gets closer. I have a pdf about the change. The old power valve part numbers end in 02, and the updated ones end in 03.
That is news to me, great info and I am pinning this for others to see.
2001 and just finished a repair for the power valve tooth striking the piston. I'd question that they changed anything, because even now that it's reset it still sits very close
@@TheTyphoon365 Those clearances are close for sure. This one I build is srarting and running very well. I know some people hate the yamaha power valve engines. I am enjoying working on them. The GP1300R valves sure look sleeker than these. I hope your build goes well.
@@ShadetreeJetski going well so far, heads back on. Just need to maybe open up the little pv electric motor & double check that. Also waiting on waveeater clips in the mail.
Great video Brother the power valves in the GP 1300 r make it mu6ch less reliable than the 1200.. I've had 1200s at my shop woth north of 1000hrs and still running strong 💪
Subscribed. you got GREAT content explaining everything so thoroughly, really appreciate that!
@dsavage8751 Thanks I wanted to make useful videos.
Good video. Good job explaining. I've got a new to me pair of XLT800s that one is not cycling the valves. Need to sort that out tomorrow.
You make it very interesting Kevin.
Thanks.
Every owner's manual should have the top maintenance items. Instead, the waverunner manual dedicates a full chapter on how to boat and another on labels.
I didnt know that as I never had a manual.
When you're putting the power valves in always remember to not use the factory pins and clips that hold them in always upgrade to the lever links and this will not happen
I used waveeater clips. I am guessing you are talking about the ones like sbt puts on their engines where the entire link encapsulates the end of the power valve.
How can a bad motor cause contact with the power valve and piston? The power valve only goes so far down. I replaced a power valve and piston from sbt this summer. Probably 8 hours later i lost that same power valve. Not sure what happened but i just got another piston and power valve. I cant find where the old one went.
Simple answer is clearance tolerances. I have had two factory yamaha xl800 cylinders, the rear ones, powervalves hit the cylinder. Sometimes the pin drops out of the powervalve and it hits the cylinder, or the pin itself drops and ruins the cylinder.
Heat expansion of the metal sometimes causes the piston to hit the powevalve even if the motor for the valves is good.
Now if you have a rebuilt cylinder and it is oversized and uses an oversized piston YOU MUST SHAVE THE POWERVALVES TO ACCOMMODATE THE NEW SIZING. If you dont then you get the results you experienced.
SBT is well known for doing CRAP machine work. It is a fact you can read on any PWC forum. Sloppy cylinder boring and sleeve fitting.
I WILL NOT use any SBT cylinders. I will buy parts from them but never ever anything they did the machine work on.
So you may end up with the same results and if you cant find bits of metal you know are missing, you better tear down the entire engine and find them before you waste another 500 on parts. Guaranteed metal shavings are down in the bottom end of your engine.
On my gp800 I removed the power valves and cleaned all the carbon build up. There was a lot of greasy black sludge in the power valve compartment. Is this normal? Do you have to put grease in that compartment when reinstalling the power valve? Also noticed that new power valves come with 4 oil seals/grommets. I didn’t see any seals when I removed the old power valves. I can’t find any information on where these seals go or if they are required on the gp800. Any help would be greatly appreciated. Thanks
Those tiny seals go in the cylinder/jug where the shaft that slides through the powervalve sticks outside the cylinders. I lubed mine up with marine grease when I build them.
@@ShadetreeJetski do you have a source where I can just buy the seals?
@@cariea call the jet ski store in florida. I put their number in my latest video
Just google gp800 power valve gasket kit. You'll need to replace the gasket for the cover anyway most likely. You'll get the seals and gasket for pretty cheap all in one. Just did mine last night.
I'm guessing guillotine style valves are more prone to sticking.
I guess so. I suppose how well you tune the carbs will affect the amount of buildup as well. Keeping them clean is part of routine maintenance which most people arent going to do as it involves taking parts off the engine.
👌
My papers valves are stuck in how did you get those out?
I assume you mean the powervalves. There is an allen bolt under all that grease around your power valve holding the bronze sleeve in place.
@@ShadetreeJetski ok got them out I’m doing a top end on a gp800 I’m wondering when all this stuff is back together how I set the timing for the power valves?
On my most recent lake outing, applying any throttle position and my 2001 XL800 would slowly accelerate from idle to 5000 rpm and it would get stuck at 5000 rpm for a few seconds before it would all the sudden wake up and accelerate at a normal pace to top speed of 52mph. It will run fine if I keep it above 5000 rpm. It ran like that for a while before I took it out of the water. It would start up fine and the engine would rev good to above 5000 rpm when it’s out of the water. I noticed that the power valve servo motor isn’t working and confirmed it by testing it per service manual when I got it home. I can turn the pulley by hand on top of the servo motor to move the cables, so maybe the power valves are not stuck? Would it be a bad idea to simply run the wave runner with the Power Valve Servo Motor disconnected and manually turn the servo pulley part ways and get some low-end power back? Or would I do more damage? I don't really know enough about this, but I seem to recall reading someone on pwcforum saying that doing so would work.
I have read the same thing. You physically wire tie the powervalves open but you will have no low end power. Personally I would NOT continue to run the engine this way as it will probably build up a lot of carbon deposits from the low end bog and further cause deposits on the powervalves. I would find a used motor at least and replace it so the engine functions as it should.
Oh and yes if you can move the cable wheel by hand the powervalves are not stuck, but if you dont have an SBT built engine or waveeater clips, you are still risking those steel pins dropping out into your cylinder and destroying it.
@@ShadetreeJetski Yeah, I think you are right. I’m currently searching for a used YPVS servo motor on ebay. I’m having a hard time finding anyone here in north Georgia that is willing to work on an old 2 stroke machine. The one local shop here charged me $1200 to rebuild the carbs couple month ago, when my 800XL stopped running. It ran fine again after the carb rebuilt for a few lake outings and now this issue with the YPVS.
Thank you for posting these helpful videos.
@@MikeATL- I live on lake sinclair in middle GA and yes nobody wants to work on them and 1200 to build the carbs is insane.
@@ShadetreeJetski Wow, it's a small world. I live near Lake Lanier. Actually not too far away from you. I was shocked when that shop charged me $1200 just for the carb rebuild. I think they knew they could charge as much as they want, due to lack of competition. I'm trying to see if I can repair it myself now, since I can't afford to take it back to them for anymore repairs.
I bought my 2000 xl1200 from a guy that did no maint whatsoever can't stand people like that🤣had to remove all the powervalves and clean them all the shaft couplers were broken took alot of wd40 and carb cleaner. Replaced everything,deleted the cat that had fell apart it runs like a scalded dog now👍
I love it. His loss. Hope you got a good deal.
How can i test the servo motor ?
I tested mine and a used one I bought with the jet ski itself. Just plug it in. I am sure there is a way to bench test it but I dont have a schematic.
If the motor doesnt actuate back and forth 5 seconds after pressing the start button it probably is bad.
@@ShadetreeJetski thanks, mine bad apparently then. appreciate the help! found my issue for bogging at low speeds
Someone just bought an aftermarket power valve and left the stock one on the front cylinder.