bucking and misfiring

V

VenturiEffect

New Member
I think I might have done to many mods at one time.So ive recently got into performance mods. Mainly for speed. And torque balance. 32 tooth, sbp x chamber and a dellorto sha clone carb. I installed all of these at the same time. #65 jet in the carb extended intake manifold and 13 inch header on the pipe. From flange to very beginning of expansion bell. It starts right up. With ease I mean one turn of the pedals and bam. But when I get up to maybe 10 mph hit the gas and it like a bucking horse jerking and misfiring. Not a steady idle. Not sure what going on here. Im thing about putting the stock exhaust back on and try to tune the carb a little richer then put.the x chamber back on. Any thoights on what may be causing this? I live at sea level and not sure of the jet sizing and what not. Completely clueless when it comes to jetting. I also have replaced the the boot and plug.

SOLVED:

Gap was to small on the spark plug not sure how that happened. Also chain was loose. This thing runs like a champ now. Just need to get the jetting proper now.
 
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Yeah im going to put the stock nt on and see if it still does it. If it doesnt buck like a bronco I know ill have to play with the jets on the rt carb. Tune the rt carb with the stock exhaust and go from there. Ive never had issues like this. I was also ingormed that it could be the 32 tooth sprocket im using
 
VenturiEffect said:
Yeah im going to put the stock nt on and see if it still does it. If it doesnt buck like a bronco I know ill have to play with the jets on the rt carb. Tune the rt carb with the stock exhaust and go from there. Ive never had issues like this. I was also ingormed that it could be the 32 tooth sprocket im using
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It's very possible the 32 tooth is way too hig of gearing for your setup... have you had any port work done to the cylinder? do you have a high compression head installed? You will need a lot of extra torque to turn that sprocket on a 26" rim... I would go with a 36 or even a 40 tooth rear sprocket and tune the engine to work with one of them... Anything smaller than a 36 is going to kill your acceleration to the point it won't be able to make it into the powerband to take advantage of this gearing... Think of it like a standard car or a motorcycle that you're trying to take off from 3rd gear instead of first... it'll do it but it's gonna buck and surge all over the place until it reaches a certain speed.
 
I was hoping that wasnt the case I extended the intake manifold and x chamber to get more torque. Im more than likely going to have to get a new chain and sprocket now. And no, no port work or high comp head thats next on my list along with ramping and reversing transfer ports to 180 the jug
 
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