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last337 |
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#1
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Member ![]() ![]() Group: Members Posts: 421 Joined: 4-December 12 From: New Orleans Member No.: 15,221 Region Association: None ![]() |
Hello everyone! I got my new EMPI 40s on yesterday and I have been going through the adjustment all day today. It has been a long time since I have messed with carbs and Im not sure if I am doing this correct.
Initially I got my linkages all set up and correct with the speed screw at about 1 turn in. I have all the air bleed screws all lightly seated and mixture screws about 1 1/2 turns out. At this point it is very rich but runs well at an idle of about 900 and actually comes up really nice but is smoking and even spitting out fuel from exhaust. I figured at this point I could begin going in 1/4 turn at a time on each mixture screw to the point the engine starts to run rough then back a 1/4 turn. I did this on all and it was still smoking badly. I havent set timing or anything like that but I would assume the only electrical issue (am I wrong?) that could cause rich conditions at idle would be a fouled plug but it is running smooth and not as if it is missing with a fouled plug. I am wondering if maybe I should go another half turn on the speed screw then see if I can go in further with the mixture screws. Is there anything I can do with the air bleed to adjust this? I thought they were only adjusted for syncing and not for a rich condition. The vendor I got them from claims they have the following jets: 52 idle jets 115 main jets 200 air jets 28mm venturi 550 EX. pump jets 50 accelpump jets F11 emulsion tubes Am I oversized with that I have in there now? I have been reading the following link to troubleshoot and it says if I am over 1 1/2 turns in on mixture then my jets are too big. The problem is that I cant get it to run at under 1 1/2 turns on mixture. However, maybe I should try another half turn on speed screws? Any help is greatly appreciated (IMG:style_emoticons/default/biggrin.gif) |
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Trekkor |
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#2
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I do things... ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 7,809 Joined: 2-December 03 From: Napa, Ca Member No.: 1,413 Region Association: Northern California ![]() |
The only real adjustments are going to be with jetting.
The adjustment screws will only help balance the carbs at idle. You will need an exhaust gas analyzer to properly dial in the jets/airs with the motor running under load. On a dyno for example. 13.1-13.5:1 is a safe target for an air cooled motor. KT |
last337 |
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#3
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Member ![]() ![]() Group: Members Posts: 421 Joined: 4-December 12 From: New Orleans Member No.: 15,221 Region Association: None ![]() |
The only real adjustments are going to be with jetting. The adjustment screws will only help balance the carbs at idle. You will need an exhaust gas analyzer to properly dial in the jets/airs with the motor running under load. On a dyno for example. 13.1-13.5:1 is a safe target for an air cooled motor. KT Unfortunately I do not have access to a dyno anywhere around here. Should I try to decrease my jetting size to see if it clears up the smoke for now? What size should I try for a 2.0 liter stock with 40s? Where is a good place to buy jet kits? |
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