SOLVED!! It was a small washer (gasket) in the lower carb that was missing causing air to leak in. Put it in place and drives like a dream again 24 knots WOT 💪🙏 thanks for all the help!
Solved the same issue on my 50, the main fuel line had a split that was allowing the motor to draw air into the float bowls creating a very lean condition.
Its the high speed needle this is where the carb delivere more fuel after acceleration, it could be clogged ,also check ur timing sync if that not working
Well, it surely could be something as simple as a sync/linkage problem...Perhaps the linkage popped out of the plastic retainer on the timer base so the ignition timing is not advancing...Perhaps the link popped out that connects the two carbs, those plastic connectors get weak easily. Remove the air box cover and watch the throttle plates open with the engine off, while an assistant slowly pushes the control box throttle to wide open in forward gear. Looks like this might be tough on your boat because the engine is buried deep in the transom well. Perhaps the linkage between the two carb butterflies is messed up.... Try this also, a very simple test....Run the engine up to where it starts to drop RPM, then tap the choke on for a second.... Did the RPM pick up for a second? If so, one of your high speed jets is dirty. If the RPM drops even further when the choke is tapped on for a second, this indicates that the carbs are not running lean, don't want you to rip them apart needlessly.
One question this was an epic reply and makes sense. On my johnson I believe when at full throttle (when the bogging happens) it stops you from putting up the choke. Is there a way to manually do this on the engine itself as I dont think the gear level will let me try that test (which sounds very valuable at eliminating the problem)
@@JasonDainter Yes, I believe you are right. Some of the engines do have a spring that pushes the chokes on when the throttle is up high, this was due to a partially automatic choke system that was not that reliable. Which year/model do you have. In any event, you could easily do this back at the engine on the engine featured in this video.. Simply disconnect the choke linkage rod connecting the two choke levers. Now, gently/partially close each choke, one at a time while the engine is faltering at high speeds. If the RPM picks up, then you know you have some sort of problem with that carb. If the RPM drops, that carb is working OK. If closing the choke makes no difference, then perhaps you have a fuel supply issue on that cylinder, or the engine is simply not running on that cylinder. PLEASE, be very careful, you could get caught in the spinning flywheel. Don't attempt this if you can't get at the engine easily (deep transom well/pontoon boat, etc). You certainly don't want to fall in the water either.
Carbs need to be cleaned/rebuilt. Making sure the linkage is set properly will not hurt either. Pull the hood off and when you throttle it look to see if the linkage is advancing to wide open throttle. If it is then it’s about certainty a carb/ fuel issue
Justin Roberts thanks a lot. Had cleaned both carbs out just before this, so think it's linkage. Not so familiar how to adjust linkage but going to check in my manual! Any tips there?
@@JasonDainter if you have a manual that is great! it will tell you pretty much everything you need to set the linkage. Only tip i could give you on that is to follow the steps precisely one by one. It may not even make sense but just do as the manual says. These motors have to be pretty much dead on to run correctly, as i have a 55hp myself.
Har du fått den att funka igen? För jag tänkte nämligen köppa en sån här motor, exat lika Dan Johnson 55hk men ser så många som har problem med den här motor och blev osäker nu. Men fixade du problemet eller går de inte?
What is the knob underneath where you put the key in start the boat seems like you can turn it right or left does that have something to do with the idle or choke
@@JasonDainter just worked it out. Does your forward control box have a tightening screw under the keyhole? Mine was loose so I would put the throttle forward and even though the handle stayed there the actual butterflies on the motor would relax closed. Tightened the shit out of it and tested with intake cover off while looking back at butterflies and now they stay at fully open when throttle is forward :)
@@tomwaters5115 no way! This is super exciting! Boat is in storage but this could make sense going to check it asap!! I have a feeling though I tested mine with cover off to see butterflies and with full throttle they seemed 'fairly' open but maybe very slightly closed, will check it out thanks a lot for posting the tip!
@@JasonDainter tested it again and was still having issues, and I believe it's a fuel issue, pulled everything apart and the fuel hose delivering fuel from top carb to bottom carb was leaking, and my vacuum line to the airbox cover was missing... plus my fuel connector off the fuel hose from the tank was leaking too... I'll fix all these issues and get back to you Jason
@@tomwaters5115 thanks for update! I've found out the water also its hard to fully replicate making it quite hard to diagnose. Leaky fuel hose sounds like a good culprit though
SOLVED!! It was a small washer (gasket) in the lower carb that was missing causing air to leak in. Put it in place and drives like a dream again 24 knots WOT 💪🙏 thanks for all the help!
Solved the same issue on my 50, the main fuel line had a split that was allowing the motor to draw air into the float bowls creating a very lean condition.
Thank you!! Will investigate that on mine...
Its the high speed needle this is where the carb delivere more fuel after acceleration, it could be clogged ,also check ur timing sync if that not working
make sure butterflys in carbs are straight 90 degrees at full throttle.
Well, it surely could be something as simple as a sync/linkage problem...Perhaps the linkage popped out of the plastic retainer on the timer base so the ignition timing is not advancing...Perhaps the link popped out that connects the two carbs, those plastic connectors get weak easily. Remove the air box cover and watch the throttle plates open with the engine off, while an assistant slowly pushes the control box throttle to wide open in forward gear. Looks like this might be tough on your boat because the engine is buried deep in the transom well. Perhaps the linkage between the two carb butterflies is messed up....
Try this also, a very simple test....Run the engine up to where it starts to drop RPM, then tap the choke on for a second....
Did the RPM pick up for a second? If so, one of your high speed jets is dirty. If the RPM drops even further when the choke is tapped on for a second, this indicates that the carbs are not running lean, don't want you to rip them apart needlessly.
kramden I don't think it popped out... But I think it might need proper syncing
kramden very helpful tips I'll give this a try thanks
One question this was an epic reply and makes sense. On my johnson I believe when at full throttle (when the bogging happens) it stops you from putting up the choke. Is there a way to manually do this on the engine itself as I dont think the gear level will let me try that test (which sounds very valuable at eliminating the problem)
@@JasonDainter Yes, I believe you are right. Some of the engines do have a spring that pushes the chokes on when the throttle is up high, this was due to a partially automatic choke system that was not that reliable. Which year/model do you have. In any event, you could easily do this back at the engine on the engine featured in this video.. Simply disconnect the choke linkage rod connecting the two choke levers. Now, gently/partially close each choke, one at a time while the engine is faltering at high speeds. If the RPM picks up, then you know you have some sort of problem with that carb. If the RPM drops, that carb is working OK. If closing the choke makes no difference, then perhaps you have a fuel supply issue on that cylinder, or the engine is simply not running on that cylinder. PLEASE, be very careful, you could get caught in the spinning flywheel. Don't attempt this if you can't get at the engine easily (deep transom well/pontoon boat, etc). You certainly don't want to fall in the water either.
Im having the exact same problem. Going to try cleaning the carburettors. Did you figure it out?
dudeadrian did you figure your issue out?
yes. the throttle and gear controller i had was the wrong way for the motor. pushing the throttle cable when it was supposed to pull it.
@@theiluvskatesfrnd You mean the part you actually push with your hand when you drive was the wrong way around? or in the engine?
the part you push with your hand.
Hey man, nice boat . I do have the same motor and I wanna know what gas mix do you use at this motor ?
I have the same motor as well. You propably figured out by now, but the miing is 2% since it is a 2 stroke motor.
@@olivermadsen9578 yep
Susspect it could be a carb issue. did you setup the carbs mixture etc? i have a 78 im trying to get running and have different carb issues.
Mathew Levett carbs were fully cleaned out before assembling (rebuilt the whole lower unit). I'm suspecting it's a link and sync issue
check the bulb and fuel line, and vent on tank,
Thanks will check! Determined to get this fixed this summer!
Is there an easy/go to way to check for leaks in fuel line?
same problem- solution??
Paddy Gilbert figure it out?
Jason Dainter nah mate never did, not the most liked motors out for review. Ha ha
Carbs need to be cleaned/rebuilt. Making sure the linkage is set properly will not hurt either. Pull the hood off and when you throttle it look to see if the linkage is advancing to wide open throttle. If it is then it’s about certainty a carb/ fuel issue
Justin Roberts thanks a lot. Had cleaned both carbs out just before this, so think it's linkage. Not so familiar how to adjust linkage but going to check in my manual! Any tips there?
@@JasonDainter if you have a manual that is great! it will tell you pretty much everything you need to set the linkage. Only tip i could give you on that is to follow the steps precisely one by one. It may not even make sense but just do as the manual says. These motors have to be pretty much dead on to run correctly, as i have a 55hp myself.
Also: Make sure there are no leaks in the fuel supply between the gas tank and the motor.
@@BrianPaulCinematography is there an easy easy way to check for leaks in fuel line?
Har du fått den att funka igen? För jag tänkte nämligen köppa en sån här motor, exat lika Dan Johnson 55hk men ser så många som har problem med den här motor och blev osäker nu. Men fixade du problemet eller går de inte?
theyre pretty solid engines to be honest. This issue is likely fixed by a link and sync process ( Brandons Garage has good videos on this).
could be an issue with the ignition coils, could have a weak spark under load
What is the knob underneath where you put the key in start the boat seems like you can turn it right or left does that have something to do with the idle or choke
I believe its a tilt/trim thing for boats that have it, my boat doesnt have that so it doesnt do anything when you turn it. Could be wrong though.
Sorry GA_Aztec was correct it adjusts friction for the throttle (confirm in manual)
Did you get this sorted? I’m having the exact issue on my 55 1979
Sadly not yet. Im suspecting a carb/link and sync issue but havnt had time to fully diagnose. Let me know if you figure out your issue!
@@JasonDainter just worked it out. Does your forward control box have a tightening screw under the keyhole? Mine was loose so I would put the throttle forward and even though the handle stayed there the actual butterflies on the motor would relax closed. Tightened the shit out of it and tested with intake cover off while looking back at butterflies and now they stay at fully open when throttle is forward :)
@@tomwaters5115 no way! This is super exciting! Boat is in storage but this could make sense going to check it asap!! I have a feeling though I tested mine with cover off to see butterflies and with full throttle they seemed 'fairly' open but maybe very slightly closed, will check it out thanks a lot for posting the tip!
@@JasonDainter tested it again and was still having issues, and I believe it's a fuel issue, pulled everything apart and the fuel hose delivering fuel from top carb to bottom carb was leaking, and my vacuum line to the airbox cover was missing... plus my fuel connector off the fuel hose from the tank was leaking too... I'll fix all these issues and get back to you Jason
@@tomwaters5115 thanks for update! I've found out the water also its hard to fully replicate making it quite hard to diagnose. Leaky fuel hose sounds like a good culprit though
does anyone have a fix?
I still have not resolved it.
Barely can understand his accent and the wind blowing makes it almost impossible to understand!!!
Yeah it was a tad windy granted. As for my accent, it's British English, that's just how we speak I'm afraid.