intermittent idle issue

[guywithboat]

Hi All,

I have a 1967 Johnson 4 cylinder. I just rebuilt the carb and fuel pump. Some times it idles in gear great, other times it doesn't like to start and idle. It runs good at WOT. Any ideas?

Thanks.

 

[AlanR]

Re: intermittent idle issue

Whats your compression?

 

[F_R]

Re: intermittent idle issue

Here's a sneaky one that'll get ya: Does it idle with the hood off but not on? That's caused by exhaust smoke getting under the hood, usually because somebody left the spongy seal ring off the top of the water pump housing.

 

[guywithboat]

Re: intermittent idle issue

Well, I thought my compression improved a lot since it actually starts and runs good in the lake. However, my compression on #1 cylinder only improved by 5. I am going to pour in and fill up completely - seafoam in all cylinders and let it soak for a few days. *I turned the engine horizontally*

 

[guywithboat]

Re: intermittent idle issue

F_R,

That was an issue at first. But now it is not. Thanks for the help.

 

[guywithboat]

Re: intermittent idle issue

Compression was brought up to 50 on #1. I think I will replace the gaskets to try to illimintate any easy issues.

 

[jtexas]

Re: intermittent idle issue

compression on #1 is 50? There's your problem. What are the numbers on the other cylinders?