sick yamy 115 4 stroke

[honda 50]

Hello guys. Weird stuff going on on my 2002 115 4 stroke motor. Can't achieve above 4700 rpm ( still same old prop) .Takes everything to get on step. And when engine gets warm and i come off step can't get past 8-9 mph and thats with throtle all out.after a 15-20 min like this it gains 100 rpm here and there and eventualy gets back on step but very gutless and still miles away from 5000-6000 rpm. changed the fuel filter and it still does it plus there is no water in fuel. ( my kicker works fine) . On a crazy note if i press the throtle botton on lever i can rev the engine up to roughly 5200 but sounds like a rev limiter kicks in. Also i can get more rev in reverse i'm baffle Any ideals ??? Been reading about the VST filter and know for a fact that it has never touched, I run only fresh water if that makes a difference. Thanks a million Frank

 

[patbalmos]

Re: sick yamy 115 4 stroke

Sounds like your engine is starving for fuel you need to pull the intake manifold off and remove the vst. Take the cover off of the vst and clean the screen located at the base of the high pressure pump. If this doesent help then you need to pull your injectors out and send them to be cleaned.

 

[99yam40]

Re: sick yamy 115 4 stroke

If you have run it that way for as long as you have said, I would start with the basics and do a leak down test or compression test if you can not do the other to make sure the motor is still sealing the cylinders properly.
Then monitor the fuel pressures to see what is going on, and it would be good to get it hooked up to some diagnostic equipment to see everything you can

 

[honda 50]

Re: sick yamy 115 4 stroke

If you have run it that way for as long as you have said, I would start with the basics and do a leak down test or compression test if you can not do the other to make sure the motor is still sealing the cylinders properly.
Then monitor the fuel pressures to see what is going on, and it would be good to get it hooked up to some diagnostic equipment to see everything you can

It only acted up on the last day of my fishing trip and i was 100 miles away( by boat) when it happen i just wanted to make it home. Will try to see if i can rig a pressure gauge to it.

 

[honda 50]

Re: sick yamy 115 4 stroke

Ok just bought a new vst filter $65.00 and i will take all 4 injectors to boat dealer for ultrasonic cleaning. They quoted me a half hr labour for the cleaning. Will start the job tomorrow. Will keep you guys posted. Thank you

 

[honda 50]

Re: sick yamy 115 4 stroke

Ok update time.Got the filter removed and replaced,Not too too bad of a job ,especially for a first timer. The filter was partially clogged,and i'm now waiting for the dealer to call me back with 4 freshly clean injectors. I will re-install them tomorrow ,run it in my yard for leak check then take the boat to the lake and see. Will keep you posted. Thanks again Frank

 

[honda 50]

Re: sick yamy 115 4 stroke

Well problem solved... And this was the problem. Crazy how just little debris can create such a mess with my engine. Total cost 130.00 vice 450 at the dealer.. I also added an inline fuel filter,it was super easy and cheap ( $16.00)so now i have double filtration before the the fuel gets to the VST. Thanks again guys.. Indian Frank