clarkie Posted February 17, 2009 Report Share Posted February 17, 2009 hi this is a tech question , i have fitted a oko carb on my montesa 315r and for it to run smooth the air screw has to be wound right in this leaves me with no adjustment at all on the air screw. so can anyone tell me which jets or anything to change this. many Thanks jason... Quote Link to comment Share on other sites More sharing options...
laser1 Posted February 17, 2009 Report Share Posted February 17, 2009 The pilot jet meters the fuel for the air screw and progression circiut. If you want to let in more air, you will need to let in more fuel. You need a larger pilot jet. Quote Link to comment Share on other sites More sharing options...
stork955 Posted February 17, 2009 Report Share Posted February 17, 2009 Gday, first thing to do is make sure the air filter, exhaust and spark plug/ignition timing are all clean and correct for the bike. Doing this now will save hassle later... Next check that the carb slide is almost fully down - you need some freeplay in the cable and the slide should be set roughly 1-2 turns in from fully down - this will make sure that the bike is actually running on the idle circuit and not up on the needle. Then - if your airscrew is right in and it still runs you need a larger idle jet (the air screw actually restricts air on this carb) and it needs less air so this is the same as needing more fuel. The actual jet size you need will depend on many things but my suggestion is to go up 2 sizes from what you have now eg if you have a 35 go to a 45 and see what happens. Your airscrew should end up about 1.5 turns out from lightly seated when it is sized correctly. Then check for clean throttle response as you open the throttle. If it stumbles you can either play with the idle mixture or better still change slide cutaways. HTH, Cheers, Stork Quote Link to comment Share on other sites More sharing options...
clarkie Posted February 18, 2009 Author Report Share Posted February 18, 2009 hi thanxs for help but stork what do you mean change slide cutaways never heard that before mind you i am new to carb setups Thanks jason Quote Link to comment Share on other sites More sharing options...
laser1 Posted February 18, 2009 Report Share Posted February 18, 2009 Here is a link to a good online manual about carb basics that wil help. http://www.thisoldtractor.com/gtbender/mg_...orto_manual.pdf Quote Link to comment Share on other sites More sharing options...
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