20HP At wits end.

[i386]

Ever since I've had this engine, it starts if and when it wants to. If I spray some mix into the carb, it might run and keep running. It might hit a few licks and stop. It runs good when it runs. Let it sit for a few minutes and it takes a lot of work to get the sob to start again.

I have:

Good strong blue spark on both cylinders with spark tester.

Installed new fuel pump diaphragm and gaskets. I noticed one of the reeds in the fuel pump does not fit tightly against the hole. It's close, but not tight like the other reed. I didn't dare try and bend it to correct the problem. I tried to test the fuel pump, expecting a steady pulse of fuel into a container when I pull the rope. It does not. My seloc manual says test with a pressure gauge. So I don't know if I have a good test. Does a diaphragm pump require back pressure or should my test work? Can I bypass the fuel pump altogether and use a gravity feed system (for testing) to rule out the fuel pump?

Taken the carb apart and cleaned it (many times).

New gas tank, line and filter.

 

[eurolarva]

Re: 20HP At wits end.

Seems crud is a problem with the idle circuits in these carbs. What I have found to work is to remove the idle mixture adjust screw and spary either wd 40 or carb cleaner in the screw hole then put the screw back in and pre set it the way it was before. The three tiny holes in the carb tend to either varnish or get gummed up and if one of them holes is plugged the idle dont work. Another problem I had is the cam follower to the throttle linkage should have an air gap equivalent to a sheet of regular paper. When I had mine so the cam was touching it seemed my motor was more prone to flooding. . There is a screw that is eccentric and by loosening the screw you can turn the outer collar so you can adjust it so it misses or touches. Could be something else but I have had these problems with my chrysler.

 

[i386]

Re: 20HP At wits end.

Seems crud is a problem with the idle circuits in these carbs. What I have found to work is to remove the idle mixture adjust screw and spary either wd 40 or carb cleaner in the screw hole then put the screw back in and pre set it the way it was before. The three tiny holes in the carb tend to either varnish or get gummed up and if one of them holes is plugged the idle dont work. Another problem I had is the cam follower to the throttle linkage should have an air gap equivalent to a sheet of regular paper. When I had mine so the cam was touching it seemed my motor was more prone to flooding. . There is a screw that is eccentric and by loosening the screw you can turn the outer collar so you can adjust it so it misses or touches. Could be something else but I have had these problems with my chrysler.

Thanks!

When I put the thing back together, I followed Joe Reeve's instructions for setting the idle. FWIW, the engine did respond to the idle adjustments.

My carb kit came with a new welch plug. The welch plug on the carb appears to be covering where the end of the needle goes.

I did not remove the plug because:

I don't know how.

I don't know what's under it.





I will try your suggestion though.

 

[eurolarva]

Re: 20HP At wits end.

Under that welsh plug are the three holes I mentioned. I drill a small hole then use an awl to remove it. It is real easy to mess up the carb if you don't do it right. When drilling the hole you don't want to go more then an 1/16 beyond the welsh or you could accidentally drill into the carb. After cleaning the area out then the new welsh plug you just tap in place with a punch so that it holds good. If you idle is responding and idles good I would not mess with this area. Sounds like from your posts though that your motor might be flooding. When motor wont restart look at your plugs and see if they are wet with gas. If so you will need to find out why.