(Help) Clone Carb Issues

CP903 said:
Yak, I agree jet wise but it seems lean as all get out but I know that's not the case haha. It easily revs and takes forever to idle back down. Doesn't idle well at all and is hell to get started.
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What size is the pilot? I have a NR big butterfly I just worked on. I actually opened it up some more. I had to get aggressive with the pilot side, no lower oring, and drilled a good .036, and ground the sides of it (like the Dover S/A carbs are done). I opened the hole behind the mixture screw up some as well.
 
What's it doing? I run '625's w/ .058 and they're 'rich'! I'm goin2 660 and leave the let alone....@ near sea-level. Also, CHT's are 325 and EGT's are 900. However if you also have a 'Gasser' problem....IDK!
 
You've got to throttle the hell out of it to get it started. Once finally cranked if you throttle it, it wants to die. Once warmed up just a hair it has an extremely fast throttle response and takes forever to idle back down like its lean. The idle quality is not great either. Once under a load it just doesn't have any balls to pull around the track. I can put the Dover carb on, which is significantly smaller and it runs extremely hard. I believe it's jetted at a 56. Once again, I'm not an advocate of either company nor am I trying to trash talk either one as well. Just curious of the facts.
 
Chance; For some reason you are very lean and i don't think its a jet problem.....Get It running and spray some carb cleaner around all the joints and/or areas w/gaskets you will find the problem area, as engine speed will change notably..............Dave ps don't forget fuel pump and lines
 
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I agree with Barry on this, if its not coming back down right when you let off, you need to go bigger on the pilot jet, or possibly bigger on the pilot and main both. Someone else mentioned earlier about elevation, if these carbs were tuned in a shop at 650 elevation, and your at 450, your gonna need to do some fine tuning to get them working right for where you are. I have a holy moses from dover, it came with a 38 main, .24 pilot, i had to change the main to a 39 and pilot to a 22 to get it to work best here where i live, but once i did, it had great throttle response and was a great carb for me. Dont give up on them, you will get it figured out soon. Sounds like having one of each alky and gas carbs is only making it more difficult on you to figure them out, try concentrating on just one at a time, and do what Dave told you to do, get it running and spray carb cleaner around the carb, gasket area, fuel pump and lines, especially around the pulse line also. I suspect if it is running lean, you have a leak in the pulse line that isnt allowing the carb to pull as much fuel as it should.
 
I'd change the e-tube, sounds like the e-tube has an I.D. that is too large for this application or the wrong holes on it were enlarged. Main jetting is a touch rich but should run ok. If you have a carb that is unresponsive to jetting changes and finiky its normally a safe bet that the e-tube is wrong for the application.

www.Racingcarb.com
 
OR possibly worse case scenario is when work was done on throttle bore; chip,foreign material entered; or pilot-lo-speed orifice was damaged by reamer
 
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Do you guys ever wonder what the final answer was????????Are they to embarrassed to say Gee I forgot to plug the port in my carb adapter;......or sumthin not terribly difficult
 
Not quite there hotrod. Haven't had an opportunity to look at it just yet. Unfortunately in order to do these activities with my kid I have to work for a living. I will update soon and thanks for all the suggestions guys.
 
I know very little to nothing about your carb, but it sounds to me like an air leak somewhere. Bolt a plate, with a gasket, on the carb with a fitting, to pump pressure into the engine, and spray around the carb with some soapy water. If there are any bubbles you have an air leak.
And those jet sizes?? A .065” jet is 165% bigger than a .040”. A .058” is 110% bigger. I think that would be a much closer choice.
Just wondering; how did you check the size of the Jets? Just asking because the builder sounds like an experienced carb person and I’m wondering why he would put such a big jet in that carb.
Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory.
 
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