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Discussion Starter #1
Ok I did a search and came up blank... trying to get my 302 sbe x headed carb engine to like me... I had 55° of timing in it my first ever pass on accident I couldn’t see the mark and thought it was 30° so I took it to 30 still stumbled off the line next two passes. Got it home. I put a fresh plug in each side before every pass. I took it down to 20° of timing to see if it like it better than 30° well I revved it and it went quiet and then shot a nice 4’ flame out the carb. Never seen retarded timing do that only too much advance... it’s a vic jr single plane intake 750 Barry grant (I know it’s too big I’m working on getting a 650 main body) I’m on 100LL fuel. Planning on a 100hp single stage plate. Plugs had timing mark was about 1/16” away from the threads which is why I want to pull more timing. Is 20° too retarded? Would 25-26° be better? Oh yeah I forgot to mention the distributor is locked.
 

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Something sounds off. I'd expect an engine like that to want ~36° of timing.

I'd check the balancer for issues. But keep in mind that large timing changes will require retuning to carb somewhat.
 

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Discussion Starter #3
So I think I found my issue. The coil wire was barely on the coil. Put it back on and it was happier. Put it at 26° for now and turned idle screws in 1/4 turn took idle back down to 1,000 but noticed a slight buzzing in my hand when I touched the carb. Engine is grounded really well. I think the wires are junk so I’m going to order some firecore 50 and go from there.
 

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I wouldn't bother with the 650 main body. If tuned correctly, a 750 works fine on a 302.

Also, the 650 main body might be more trouble than its worth. Standard 650 DP's have a two corner idle circuit while most 750's use a four corner arrangement.
 

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Discussion Starter #5
Ok thanks for that. I didn’t know 650s only had 2 corner idle. I wish I could post pictures here. I have pics of the plugs (idle is very rich) but the base ring actually looks pretty close. And I verified TDC on the balancer best I could with the heads on.
 

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I wouldn't bother with the 650 main body. If tuned correctly, a 750 works fine on a 302.

Also, the 650 main body might be more trouble than its worth. Standard 650 DP's have a two corner idle circuit while most 750's use a four corner arrangement.
smaller than a 750 would be much better.... much!
 

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Something sounds off. I'd expect an engine like that to want ~36° of timing.

I'd check the balancer for issues. But keep in mind that large timing changes will require retuning to carb somewhat.
Ya, check for true tdc.. be sure its the correct balancer for your front cover and timing pointer is correct, sbf like timing.. 750 carb will work, people think just because its a xxx size carb then you are getting that xxx cfm, it dont work like that
 
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