Rjcamel2355
Contributing Member
Hey folks,
I have a 1999 Yamaha 3.1l. Motor has never gave me any trouble in 5 or so years of owning it.
I replaced the spark plugs, lp pumps, vst filter cleaned the o2 sensor and fuel bowl filter last year. I've had the boat out a few times this year with no issues.
Saturday I was going across the lake and it dogged down on me, and didnt want to go. I let off a bit and then put the throttle to it and it took off cruising WOT then it would cut way back, pick up for a second cut back and it even died a few times. Once it started cutting in and out if I tried to give it more throttle it would die. If I started it back up it ran great for a little bit again and the same thing would happen again. I could pump the primer bulb and it wouldn't help at all, but it was squishy, and not firm which lead me to think fuel was the issue..... made no sense it didnt improve with pumping.
Today, I cleaned the vst, and fuel bowl filter. checked the plugs all were a little dark but didnt look bad, no signs of leaning out that I could see on the plugs. I ran compression and all 6 were between 105-108psi (by my China gauge). Which match perfectly to the last 5 years I've had it and checked them.
Am I missing anything? Could it be time to have the injectors cleaned, new O2 sensor?
I have a 1999 Yamaha 3.1l. Motor has never gave me any trouble in 5 or so years of owning it.
I replaced the spark plugs, lp pumps, vst filter cleaned the o2 sensor and fuel bowl filter last year. I've had the boat out a few times this year with no issues.
Saturday I was going across the lake and it dogged down on me, and didnt want to go. I let off a bit and then put the throttle to it and it took off cruising WOT then it would cut way back, pick up for a second cut back and it even died a few times. Once it started cutting in and out if I tried to give it more throttle it would die. If I started it back up it ran great for a little bit again and the same thing would happen again. I could pump the primer bulb and it wouldn't help at all, but it was squishy, and not firm which lead me to think fuel was the issue..... made no sense it didnt improve with pumping.
Today, I cleaned the vst, and fuel bowl filter. checked the plugs all were a little dark but didnt look bad, no signs of leaning out that I could see on the plugs. I ran compression and all 6 were between 105-108psi (by my China gauge). Which match perfectly to the last 5 years I've had it and checked them.
Am I missing anything? Could it be time to have the injectors cleaned, new O2 sensor?