1998 Yamaha 225 OX66

[davidzima]

Ok, at this point I am thinking O2 sensor.

Model number S225TXRW

What I know:
Motor has cut out while running at 4000rpms once. It has stalled at idle several times. I have gotten in the habbit of pumping the bulb which is not always hard but never sucked flat like restricted flow from tank. Pumping the bulb seems to help before getting up on a plane as the motor will act fuel starved if you don't. Once you pump bulb it will jump up on plane and run. Then back at dock, will try to start to put on trailer and it may or may not start. will act fuel starved like catching and coffing. If you wait 20 minutes or so it will start and idle fine, although I work the fuel bulb like crazy just in case.

No buzzers/warnings

What I have done:
Replaced 10 micron Racor filter.
Cleaned Screen/filter on VST tank pump, boy that sure is a nice $50 Oring on there.
Blew back main tank line.

Always put Stabil Marine 1oz per 10 gal on fillups.

Could it be the 3 fuel pumps that feed the VST tank? or O2 sensor?

Thanks,
David

 

[nickmo]

Re: 1998 Yamaha 225 OX66

Yes. It was on my motors. The low pressure pumps need to be replaced every 3 years or so depending on usage. They're easy to do and fairly inexpensive. About $35.00. If you haven't changed them in a while, I'd would just for prevenative maintenance.

 

[rodbolt]

Re: 1998 Yamaha 225 OX66

price increase, they are about 52 bucks now.
and they still dont last very long. yep about every 3 years on a 3.1L
first symptom of a bad diaphram,poor idle and fuel sheen on the water while idling at the dock,second is it runs out of fuel at the top end,the third is a race.
its a race to see if a rod exits the block BEFORE the piston skirts fail.
usually once the primer is pumped up had then keep light pressure on it and see if it goes flat again,if it does you have a leak,pump diaphram,filter or VST needle.

 

[davidzima]

Re: 1998 Yamaha 225 OX66

Thanks, I will do so and report back.
Greatfully,
David

 

[davidzima]

Re: 1998 Yamaha 225 OX66 - FIXED

Re: 1998 Yamaha 225 OX66 - FIXED

OK, I replaced the 3 fuel pumps and problem still persisted. What I found that I did not see the first time I checked was WATER in the racor filter, WATER in the filter on the motor, and you guessed it WATER in the VST tank. Took off fuel rail and WATER. Well I draind 30 gal of fuel out of the tank and line through to the motor. Apparently I got bad gas when I filled up last time.
I hope I didn't do any dammage. It idles a tad rough, like a miss, but at high rpms it runs smooth.
Thanks for your help,
David