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Posted

ok so i did a comp test and a leakdown and it passed with flying colors put on new carbs, redid all the wiring changed and gapped plugs checked pick up gap, and cleaned the strator, im running super unleaded in a 32:1 ratio..... cleaned airfilter and started to dail in my jetting when i noticed that it would only run good when it was really lean around 280-290 mains but would putter and pop and sputter on the top end but when i bumped it up to 300-330 mains it would run like shit... would sputter and wouldnt go into power band to tried changing neddle position and adjusting air screws and still ran like shit with the bigger jets so i bumped it down to 300 and still nothing then she died...so now im gonna have to upkk the head and hope for the best... but my thought is when the guy i got i from said it ha some porting done im thinking it was a dremel job in someones garage banghead .... so i was wondering if anybody thinks the same or has any other ideas why it would be doing this... and what a good mx port costs???

Posted

a friend mine had an issue like yours......he pulled the cylinders and notice that the "port" job was not correctly polished......he send the cylinders to a real guy and problem solved.....

Posted

oh wow thats a good one

 

so the bike just DIED?? man must be the PORTING!!

 

did you loose spark? did you run it out of gas? did your coil take a dump did your stator pick up fall off? is your stator pick up set right? is the head messed up? did you break a reed from the "sputter'n? are your carbs synched right? are the needles in the same posiston.?

Posted

no im sorry for how i worded it but basically im not asking why my shee is dead even though it lives now just turns out the kick gear was all messed up and was the culprit of making the horiible clunking noise and it not kicking over... but basically what i am really asking is why is it that when i put the bigger jets on it runs like shit but when i put on the smaller jets it runs great but has a realyl bad top end and yes everything with my carbs is in order (float lvls, pilot jets, needle position, slides are in right, no air leaks, air screws are right choke tube in place, synched, idle set.....) the carbs could not be in better shape reads are in great shape and engine has great compression about 120 in each cylinder... so waht i was thinking that the porting done was not the best there for resulting in my jetting issue??????

Posted

what the heck is wrong with this guy ???

 

 

try this

 

what main does it run good on?

 

280's?

 

then put in a 290 OR a 300 and drop the needle down one clip at least. if its in the middle if its NOT in the middle PUT it in the middle and start all over.. are you SURE the carbs are synched AND the slides are in the right spots. plugs gapped right? .20 or so?

 

if the trans tunnels and the intake area are baby butt polished smooth they can cause SOME jetting issues with out measure ments and having the cylinders in my hands i cannot tell you if the trans and exhaust are messed up.. try to jet it out you may also have a case air leak or something?

Posted

yes the bike is in perfect order... everything is to spec right now... i myself do quite abit of work on vechicles although two strokes a very new to me lol... but yes the plugs are gapped correctly... the carbs are all in order has 115 psi in each cylinder and did a leakdown test already has good gas 32:1, completely redid entire wiring harness, and i have a clymers manual so i know what it should all be... but ok heres how i started my jetting 330 mains, 25 pilots, needle middle clip, air screws 1.5 turns out. and as i went down on the jetting the bike would run better but would pop and sputter at wot so i moved them back up moved my needle clip leaner and adjusted my airscrews help but still runs like crap.... so once again i bumped the jetting down and adjusted everything again but still ran like crap or had poppy and boggy topend :wacko:

Posted

if its poping and boggin on TOP the mian is too small OR your carbs are not getting enough fuel. might check your fuel lines and remove the needles and seats and make sure there are no bugs or grass or do do in there. also check the flow out of the pet cock?

Posted

oh also unscrew the plug caps from the wires if the end of the plug wire has rust you might need to clip it back a lil and get a good connection in there or replace the caps with some NGK type?

Posted

i have already replaced my fuel line and filter is new.. but the petcock looks pretty dirty so i might try and cleaning that.... but the carbs are almost new and are completly spotless and have been rebuilt by me personally and everything is to spec.... but you said i might just be able to replace the caps? not the entire coil? because that seems fairly enexpensive so i might just try for the hell of it

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