88 vro 150

[npierski]

I'm needing some help. My motor will run fine at times and at other times she will not even plain out. I have recently rebuilt cards, new fuel(ethanol free), and changed plugs. This motor has been doing this for about 10 yrs and the shops have yet to fix it. What it does! When first firing up it will high idle and miss like crazy, does not have power under load but will rev up fine. When trying to plane out if it does not clear up then it will die, but will fire right back up. If the problem continues to occur you can let the motor sit for about 30 mins start it and it will run like a dream for the rest of the day. Sometimes at wot it will cut out but clear up and smooth out. The boat will still do about 65mph when running properly. This problem does not occur every use which is making it difficult to find. Also the plugs keep fouling out so I am going to plug off self mixer and start mixing my own fuel. Any help would be greatly appreciated.

 

[Docksidemarineservices]

You will need a timing light. Hook it up to the engine and run it until it starts to act up. See if you are losing ignition or if it the ignition becomes erratic.

 

[npierski]

since it normally does it under a load can i put it in a tank and put it under a load. Also do you hook the timing light just as you would on a car?

 

[racerone]

Run it on the boat out on the water.----The idea here is to hook the timing light to the #1 cylinder and lay the timing light on a seat / floor and observe the flashing light to see how spark behaves.---Repeat with each cylinder.----A steady flashing light means steady spark.----No flash / interrupted flashing and you have found the faulty cylinder.

 

[npierski]

Ok. Thank you I will try this next time i go to the lake!