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Author Topic:   carb problem??
Dirt Full Roller

Total posts: 28
posted May 04, 2003 08:40 AM
need some advise, engine pulls hard on restarts and higher rpm,and the upperside of the mid range but on the lower side of the rpm . or right off the corner, we have little problem ,car seems sluggish like it mabey arich carb. condition. new willeys 4412 with 74 jets and 3.5 power valve. have never used a3.5 valve before but this is what it came with. am I on the right trail, or is ther onother problem?, ignition ,including the dist. is all new . the float is set properly and fuel press is 7 [gas] ideas??????



Earl Parker II
Dirt Full Roller

Total posts: 39
posted May 04, 2003 02:58 PM
I would turn the idle speed ***** until the butterflies were within .020" of the bottom of the transfer idle slots (in other words, .020" of the transfer idle slots are exposed to manifold vacuum at idle), then adjust each idle mixture needle for maximum manifold vacuum at idle (as measured by a vacuum gauge). Once you know your vacuum at idle, install a power valve that opens at 1.5" to 2.0" inches below that figure, i.e., if you have 10.0" of vacuum, use an 8.5" power valve, if you have 8.5" of vacuum, use a 6.5 power valve- you get the idea. You might also want to restrict your power valve restrictions (the two holes you see when you remove the power valve) to .033" to .035".

Try the above and let us know how it works.

Almost forgot, you need between 5.5" and 6.0" of fuel pressure at idle- no less and certainly no more.

Earl Parker II

[This message has been edited by Earl Parker II (edited May 04, 2003).]

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