Yamaha 90 bogging down

[pete01]

I have a 2002 Yamaha 90TRLA that has never given me a minute's trouble. Took it out Memorial day and it ran great. Took it out on Sunday and it was hard to start but did start, idled a little rough and then when I tried to run it bogged down. This continued for a few minutes, bogging down and quitting when I tried to run. It finally idled OK but would not run. I changed plugs which did not seem to be fouled and put it on the trailer and came home. I am thinking either a fuel pump or fuel filter issue is the cause. What say you? Thanks for any help.

 

[seamule1]

Re: Yamaha 90 bogging down

Check your coils. May not be firing on all cylinders.

 

[noelm]

Re: Yamaha 90 bogging down

make sure the timer assembly moves when you advance the throttle, it is a very common fault in those and thats the symptom, they will idle, but die when put in gear and try and run.

 

[pete01]

Re: Yamaha 90 bogging down

After reading copious other posts and some investigating I believe that this is caused by the recent fuel change. My preferred gas station is now selling the Government mandated E10 gasoline. I think that I will clean the fuel system and install a Yamaha mini 10 fuel water separator and change the filters regularly. I prefer to eat my corn not burn it. Special thanks to Rodbolt for all of his replies to others, they may have helped me cure my baby.

 

[hribarj]

Re: Yamaha 90 bogging down

I have the same problem with my Yamaha 100 (same motor as the 90). I would like to check the coils and the timer assy as suggested.
Can you tell me a little more about how to do this.

Thanks
JRH

 

[dpattison]

Re: Yamaha 90 bogging down

My father has a 90hp 2004/2005 Yamaha outboard doing similar things. Its only done 50 hours total, he's been away for 8 months and just started it up again the other day. It also only had a service 8 hours ago....but like I said, 8 months ago. He had trouble starting it with the old fuel, ran it, loosened the steering up, then set off to the fuel station...it took 40 litres, then to the boat ramp. It started fine, but at 3/4 to full throttle it had nothing.....bearing in mind using the choke it revs fine, but the trottle, in water under load is a no-goer....Any ideas??? I will try cleaning out the fuel filter and the 3 carbs for him, but if it was a fuel issue wouldn't it cough and fart on the choke at full revs??????

 

[rodbolt]

Re: Yamaha 90 bogging down

full throttle,no load?
not only stupid but can lead to extensive engine damage due to a phenome known as bearing hammer.
that ting ting ting sound you hear as its winding down is the rollers hammering on the journal surfaces.
not good so quit.
simply clean the carbs,clean or replace the fuel pump,clean the fuel lines and go play.
once fuel sits in the bowls the varnish tends to stick to things and build up,just like plaque in an artery.
can lead to human deaths as well as outboard deaths.