I need the benefit of your infinite wisdom!

[jimlansing]

I have a 1986 Johnson 120hp VRO engine. I just put a new fuel pump on it without the vro pump and am adding oil with the gas. It starts, idles and runs great! until you put it in gear and acclerate. Just putting it in gear is ok, its when you accelerate that it coughs and dies. I can slowly take it up a little then push it wide open and it will eventually open up and run great at high speed until I stop or slow down, then we start the process all over again. It seems to "release" right around 2000 rpm and runs very smoothly. When the engine is in nuetral you can open it all the way up and it runs great. It's only when you accelerate in gear that it coughs and dies. Any ideas? Any and all helpful suggestions will be greatly appreciated. Many thanks in advance!

 

[F_R]

Re: I need the benefit of your infinite wisdom!

"When the engine is in nuetral you can open it all the way up and it runs great." DON'T DO THAT!!! Not meaning to be rude, but yes, I'm shouting. You are going to be sweeping that powerhead up with a broom.

Your problem seems to indicate a carburetor problem. Or linkage synchronization, probably.

 

[Joe Reeves]

Re: I need the benefit of your infinite wisdom!

That problem is usually caused by either a sticking timer base under the flywheel (retarded timing) OR clogged high speed jets (running lean).

 

[F_R]

Re: I need the benefit of your infinite wisdom!

Sticking timer base. That is the sort of thing I was thinking when I said probably linkage synchronization. The carbs are opening ahead of the spark advance because the spark advance is lagging (sticking).

Joe said it clearer.

 

[jimlansing]

Re: I need the benefit of your infinite wisdom!

That problem is usually caused by either a sticking timer base under the flywheel (retarded timing) OR clogged high speed jets (running lean).

Is this something that's easily corrected or do I need to put it in the shop?

 

[F_R]

Re: I need the benefit of your infinite wisdom!

The flywheel will have to come off and the timer base removed, cleaned and re-lubricated. Depends on your skills and/or confidence level.

 

[jimlansing]

Re: I need the benefit of your infinite wisdom!

The flywheel will have to come off and the timer base removed, cleaned and re-lubricated. Depends on your skills and/or confidence level.

I have the confidence and I'm very mechanical, I just can't find anything in my repair manual on this problem (sticking timer base) or it's solution, or the timer base at all for that matter. Do you know of somewhere that I can find written instructions? Someone else told me that I would have to go through the entire linkage and sychronization adjustment process to fix this. Is that true? There are 7 complicated steps for this process in my manual, none of which mention the timer base at all. Thanks for your advice! God Bless! Jim

 

[steelespike]

Re: I need the benefit of your infinite wisdom!

Does a little choke help it accelerate?
If so then it is likely a carb issue.