2006 Yamaha 90 4-stroke problem

[hunt1moore]

Problem started a few weeks ago. At WOT headed to our fishing spot it sputtered and started to die. I pulled back on the throttle to 5000 rpm and it ran fine at that speed.
It got progressively worse until it would only run at idle speed. The mechanic cleaned the filters from the injectors back and replaced the plugs. I cleaned the tank and replaced bulb then added fresh gas. Gas had E10 but I added Star Tron enzyme per recommendations. The motor ran great for the first trip but the next day it started over again with the same symptons and finally it would only run at idle.
Gas history includes mostly premium from the marina which I understand is non-ethanol however, without knowing better, I ran E10 in it by filling it up at a gas station as we were trailering it to the lake. Then, a few 5 gallon top-offs before I was informed about the E10. At that point I added Marine Stabil and then later (after initial motor problems) started adding Star Tron.
Again, the motor never ran "bad" as in a loss of power, it just started cutting out as if it was being turned off and on until I backed off on the throttle.

 

[hunt1moore]

Re: 2006 Yamaha 90 4-stroke problem

Since I did not get any responses to this problem I would like to try again. Any help would be appreciated.
thanks.

 

[robert graham]

Re: 2006 Yamaha 90 4-stroke problem

Do you have a fuel/water seperator? Sounds like a fuel related issue that a 10 Micron Yamaha or Racor unit might help a lot. Your fuel system screens, filters and injectors may require another cleaning. Good luck and let us know what you find!

 

[hunt1moore]

Re: 2006 Yamaha 90 4-stroke problem

Right now it is getting a new high pressure fuel pump filter, check valve and VST gasket.

 

[SecretSpot]

Re: 2006 Yamaha 90 4-stroke problem

I would try running with a 6 gal tank auxillary tank to eliminate the fuel system before the engine.

 

[hunt1moore]

Re: 2006 Yamaha 90 4-stroke problem

I would try running with a 6 gal tank auxillary tank to eliminate the fuel system before the engine.

That was already done in the original diagnosis. The fuel line was hooked to a auxillary tank and taken out on a lake where the problem occurred again. Subsequently, the injectors and filters were cleaned. Ran good for a day then started back.

 

[rodbolt]

Re: 2006 Yamaha 90 4-stroke problem

if you clean the VST ,all the filters and injectors at breakfast and reintroduce debris or water at lunch, guess what you do for dinner?

 

[hunt1moore]

Re: 2006 Yamaha 90 4-stroke problem

if you clean the VST ,all the filters and injectors at breakfast and reintroduce debris or water at lunch, guess what you do for dinner?

I cleaned the tank and replaced the bulb pump. (please re-read first post)

Anyway....the latest info that I am getting from the mechanic is that "Yamaha" told him that there are a hand-full of problems with the 10 micron screen in the high-pressure filter reacting to ethanol. Basically swelling the screen shut. They are sending a re-designed screen.
Please keep in mind that I am just relaying information.

 

[rodbolt]

Re: 2006 Yamaha 90 4-stroke problem

I chat with the RTA's at kennesaw at least 3 times a week and havent heard that tale yet.
we are having issues with E fuels swelling the filter cups making removal difficult and reinstallation dang near impossible.
but nothing on the VST filters.
have you seen the size of that filter?
its like 300 times larger than the F200,225 and 250 motors.
but sometimes its the sulfates in the fuel and the fact it can collect on the lines and be reintroduced to the VST.
sometimes I have to replace EVERY fuel line from the tank to the injectors to make it go away,for a while.
aint our gubbermint great .

 

[hunt1moore]

Re: 2006 Yamaha 90 4-stroke problem

I chat with the RTA's at kennesaw at least 3 times a week and havent heard that tale yet.
we are having issues with E fuels swelling the filter cups making removal difficult and reinstallation dang near impossible.
but nothing on the VST filters.
have you seen the size of that filter?
its like 300 times larger than the F200,225 and 250 motors.
but sometimes its the sulfates in the fuel and the fact it can collect on the lines and be reintroduced to the VST.
sometimes I have to replace EVERY fuel line from the tank to the injectors to make it go away,for a while.
aint our gubbermint great .

Yea, it makes me wonder just who all in the gubmt invested in the ethanol production facilities out west. Bet their stocks are doing great! Anyway, I heard the same about the filter cups. something about having to leave them out to dry up for a while to get them back on. Like I said, I was just relaying the info that was told to me by the mechanic. He made it sound like the screen was doing basically the same thing that the cups are doing.
I will replace all the hoses before it goes back out. Thanks for your response.
BTW, sounds like a viable class-action law suit. There has got to be several million invested by consumers in repairs.

 

[99yam40]

Re: 2006 Yamaha 90 4-stroke problem

Yea, lets sue the government and make the lawyers richer

 

[rodbolt]

Re: 2006 Yamaha 90 4-stroke problem

actually there have been a few class actions so far, all were dismissed.
ethanol belongs in my tumbler with ice, not in my fuel.

 

[hunt1moore]

Re: 2006 Yamaha 90 4-stroke problem

actually there have been a few class actions so far, all were dismissed.
ethanol belongs in my tumbler with ice, not in my fuel.

Not in an enema bag!