front cylinder diagnose!

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front cylinder diagnose!


Post by Aphelion » Tue Jan 11, 2011 4:03 pm

My front plug is sooty, rear plug looks good. Light smoke coming from front exhaust pipe. I thought I was just running rich at first, but now im thinking I am burning oil in that front cylinder. I know what can cause that, rings, valve guides, valves seals...

Where should I start? Just pull off the front head and go from there? Any tricks getting that front head off without removing motor? Ive never done it.

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Re: front cylinder diagnose!


Post by Bosheff » Tue Jan 11, 2011 4:18 pm

Stick yer finger in the pipe. Is it black and sooty. Rich fuel condition. Is it black and gooie or slick. That's oil. Check for vacuum leak. Suckin air will cause the condition you describe. Has carb recently been adjusted or rejetted or modified in any way?....bosheff

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Re: front cylinder diagnose!


Post by Cotten » Tue Jan 11, 2011 7:30 pm


You will probably find the largest vacuum leak to the rear cylinder.

Please pressuretest your manifold assembly with bubbles as discussed at" onclick=";return false;.
(O-ring manifolds are tested by the same method.)

Be certain to test the pan cover screw over each intake port, as more than a few have perforated to the port.

Good luck!


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