
11-20-2010, 09:30 PM
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CC Member
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Join Date: Dec 2009
Cobra Make, Engine: KMS427S/C #0631
Posts: 31
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Not Ranked
Quick Fuel SS-780 tuning suggestions
I have a Keith Craft 482FE in my car. The jets are as delivered, but I have changed the idle bleed, high speed bleed, and idle feed restrictors. My current settings are:
Main Jets: 69
Secondary Jets: 77
Power Valve: 6.5
Power Valve Orfices: 65 (? - I need a magnifying glass to read 'em!)
Idle Air Bleed: 67
Hi Speed Bleed: 35
Idle Feed Restrictor: 37
Idle Screws: out one turn
The timing curve is good.
My Innovate LM2 says the A/F ratio is 14.1 at idle, 13.5 cruising at 2k RPM, 14.1 cruising at 3k, 12.5 WOT.
The problem is that the plugs and sidepipes tell me that I am waaay rich (pipes are black/sooty/almost oily). Also, I when driving "spirited" the engine pulls really good, and then at 4200 RPM or so, it jumps like an old two-stroke coming up on the pipe. Almost to the point of being undrivable.
TK tells me that I have a sudden rich condition at 4200, which makes sense, except that the meter tells me I'm good and the plugs/pipes tell me I'm rich. I've thought about smaller primary jets and a higher # power valve.
Any suggestions would be appreciated.
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