I have a GY6 150cc motor in my sons go-kart. Its always been a cold starter but will run great after its started. Now it wont start. I put a new carb, hotter coil and plug, uni air intake. Put a 124 jet in the carb. I can get it to idle with the air mix screw out 5 turns but I know that's way too much. It will idle but the second I touch the throttle, it dies. I adjusted the valves at 006-008. any ideas? Should I change the pilot jet from 35 to 38? This is driving me nuts. Im running down the battery and probably putting a lot of strain on the starter. PLEASE HELP!!!!
ok thanks. I checked the air intake manifold for cracks and couldn't see any with the naked eye. I also checked all vacuum lines. I will retighten the air intake and change the fuel filter and petcock. I will probably re adjust the valves to 003 & 005 and see if that helps. Thanks again and I will respond when I find the prob so others can see the fix.
To find air or vacuum leaks .....run at around idle...mist water...ether...carb Cleaner or what ever all over arb manifold area. You are looking only for a speed change up or down..don't matter .....speed change is a leak
The problem with checking the intake manifold is that I can only get it to idle if I turn the air mix screw out 5 turns and even at that it wont idle long. It spits and sputters and oil smoke can be barely seen coming from motor so Im pretty sure that's not it. I have reset my valves and done a compression check. It read 90psi at first which is too low. I then put a few squirts of oil in the hole and it jumped to 120psi. Im guessin I have to do a top end rebuild from what Im reading. Does this sound right? Any other ideas? The kart has less than 20 hours on it and my son hasn't run it hard at all. Could I have just got some crappy rings from the factory? Any help is much appreciated.