Engine problems

esavoie

Cadet
Joined
Dec 17, 2014
Messages
6
Launched boat, start engine run a few seconds and stop would not continue running. Next day engine started,strain engine to get boat on plane. sound like engine running on three cylinders. once on plane at 4000 rpms tack would go up to 4200 rpms and back down to 3500 rpms. Change primer bulb,2 fuel pumps,gas element filter. Launch boat started fine, would not get boat on plane, rpm at 2200 with throttle w.o.
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,851
well, no questions again just statements
but this time no motor info

if you must do it this way

then check compression, spark, and timing to make sure all is good.
If it is then look into fuel problems.

as with the other place make sure your alarm system is working and you are not in the RPM reduction mode as it limits RPM to around 2000
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Not knowing which motor you have, carbs or fuel injection induction, a best guess would be a fuel related problem....specifically a plugged carb jet or a dirty fuel injector/filter....Have your carbs or injectors ever been checked/cleaned?....
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,851
Parts break down is the closest thing to a diagram I can think of.
If you plan on working on this motor yourself, a Yamaha service manual is a very good thing to have on hand
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Have the carbs ever been removed/disassembled/cleaned?....is there a Yamaha Outboard dealer around who could do this for you? Otherwise maybe you can do it with the help of a Yamaha Manual....if you're a mechanical type....
 

esavoie

Cadet
Joined
Dec 17, 2014
Messages
6
bought boat used don't know if carbs were removed/disassembled/cleaned. looking for outboard mechanic to do carbs.
 
Top