Serious running probs totally erratic! air/fuel??

motovator said:

This is my second build..this one isnt a new build like my other 66cc which runs perfectly now. I'm running an old used grubee. 6-8 yrs old?? Ran fine last year on a different bike. Has NT carb. I THOUGHT I had it built correctly on this build but when i ride it, it idles from extremely high to stall on stopped with clutch in. It will also seriously bog when throttle is eased up while riding, also accelerates on its own..sometimes..also will run perfectly at times once it somehow gets up to about 20 m.p.h. Choke makes difference but seems to run better at full choke than no choke or vice versa...theres NO rhyme nor reason to the running of this thing..ive tried different plugs..different gaps..different "pac man clamp settings...different idle screw settings and
air fuel screw settings..etc. Can someone pleease give me a clue????? Thanx. Motovator.[B/]

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motovator said:

This is my second build..this one isnt a new build like my other 66cc which runs perfectly now. I'm running an old used grubee. 6-8 yrs old?? Ran fine last year on a different bike. It doesnt have an NT carb or the new cns carb. I THOUGHT I had it built correctly on this build but when i ride it, it idles from extremely high to stall on stopped with clutch in. It will also seriously bog when throttle is eased up while riding, also accelerates on its own..sometimes..also will run perfectly at times once it somehow gets up to about 20 m.p.h. Choke makes difference but seems to run better at full choke than no choke or vice versa...theres NO rhyme nor reason to the running of this thing..ive tried different plugs..different gaps..different "pac man clamp settings...different idle screw settings and air fuel screw settings..etc. Can someone pleease give me a clue????? Thanx. Motovator.[B/]

Click to expand...

Honestly i would check first to see if your float is level, if it isn't level that will cause it to run bogged down. Also when you tune your carb make sure your engine is warmed up fisrt, if your in a high altitude i would start at the very top notch and work your way down, on the jet needle and c-clip, but if your in a lower altitude i would work my way up from the bottom notch. Also checking you jet for your gas line is good to make sure it is cleaned out and nothing is blocking your gas. I hope this advice helps!