Accel pump or timing advance?

[1st things 1st]

Hello boaters. I have an 85 century with an omc 140. It starts and runs fine and will rev up fine if I do it slowly. But when I lay the hammer down all at once, it falls on its nose and dies. Even in neutral. It just started this nonsense the last time out. Any input is appreciated........Jeff

 

[Lundlubber2]

Re: Accel pump or timing advance?

I have an 85 century with the 140 too. Also have the exact same problem!! Been doing it for a while. I've been through the ignition system and haven't found the problem. Changed fuel pump filters, carb inlet filter, hose from tank, checked all fittings and still have the annoying problem.
I'm thinking carb rebuild next.
Let me know if you find your problem!!

Thanks

 

[Bifflefan]

Re: Accel pump or timing advance?

Sounds like a carb rebuild is in the future.
Throwing parts at it is not the answer. there is an easy way to test the accelerator pump. take the spark arrester off and look down the carb (chock open, engine off) and then have some shove the throttle to full. if you see a squirt of gas go in the carb the pump is good, if not, not good.
its just that easy.

 

[1st things 1st]

Re: Accel pump or timing advance?

That is what I was thinking. The carb will be rebuilt by the weekend. I will let you know if it pulls wheelies......thanks

 

[1st things 1st]

Re: Accel pump or timing advance?

ok... Rebuilt the carb. It didn't need rebuilt as much as it needed cleaned. The pump intake orifice was plugged. After soaking and Blowing it out I had good flow. It was also missing the aluminum ball which made the pump push gas back into the fuel bowl. When I put the carb back on it still had the same problems. After some disappointment and much cussing, I took the top of carb back off, put a ball into the pump chamber and tried it. It revved up so fast it pertnear jumped off the trailer. Problem solved for now. Took it to the lake and it ran like a dream all day long. Hope this helps..