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cleaned carb new fuel lines new mags both plugs firing. only runs on one cylinder

lcs said:

cleaned carb new fuel lines new mags both plugs firing. only runs on one cylinder

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My first guess is that it is a valve problem.

removed valve covers and plugs and turned engine over and all rocker arms seemed to move the same

What's the compression at?

Look at position of valve guides in the head. Should be the same. (assuming there are guides)

lcs said:

removed valve covers and plugs and turned engine over and all rocker arms seemed to move the same

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With both plugs removed, determine which plug hole you can hold your thumb on and compression doesn't blow it off when cranking.

lcs said:

removed valve covers and plugs and turned engine over and all rocker arms seemed to move the same

Click to expand...

checked compression and is approx same when cranking engine. is he part on bottom of carb a fuel pump. it plugs in to a wire.

lcs said:

checked compression and is approx same when cranking engine. is he part on bottom of carb a fuel pump. it plugs in to a wire.

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No, it a fuel shut-off solenoid.

First thing I would do is check the valve adjustment. They may all work and appear the same but adjustment may be off. I can send you a Service Manual for your engine IF you like. Address below, put in proper format and remind me, engine model number and what you want

Walt Conner
wconner5 at frontier dot com

lcs said:

cleaned carb new fuel lines new mags both plugs firing. only runs on one cylinder

Click to expand...

I suspect your problem is with the dual barrel carb.? Check to see if you may have lost one of the bushings for one of the main needle fuel valves. I have seen this before.
One cylinder is being starve of gas, while the other is getting plenty. Hence this is why you are not finding any electrical problems. You stated you cleaned the carb... I think you may have lost this easy to loose part... and did not notice it.