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tuning my cub


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trying to get this thing right just wondering if anyone knows where about i should be on jetting and timing and gearing and everything honestly.. its topping out way to fast. its a 421 cub 35mm pwk's, vforce 3's, 68mm pro lite pistons 4mil stroke, cool head 20cc domes, +4 timing, cpi inframes, 15/40 gearing, lockup clutch, straight cut gears, any advice pointers are great. if anyone knows where about a good setup would be for my motor i'd appreciate it if yal would tell me if yal know where about i should be on everything... thanks... trying to get most power i can out of it and the way its running now i know its not right... or as good as it could be. so how/what can i do to get more power and make it run better thanks.

 

where about should i be on all my stuff... what works good with my motor... what can i do to get more power out of it the simplest way?

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first... get a set of 39mm pwks..... the 35s are holding the motor back... second, buy a set of shearers they rev out farther than the cpis do... I was running 160 mains 50 pilots and cel needles in my 39 pwks when it was on race gas... this was at 900ft above sea level....

 

Also, cubs love timing.....

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i live on the ms gulf coast so its gotta be sea level. im not sure what pilots mains and all im runnin ill find out. what all goes along with changing carbs? you gotta get new intake boots and filters or what?

also what will adding timing do? how much to add? thank yal ill try to get in the carbs soon and find out what main jets and pilots im running will that reaLLY help yal help me lol knowing where that is ill find out today.

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every motor is different. what one guy runs for jetting is not always what works best on your motor.trial and error my friend.don't be affraid to rip into those carbs and do some changing on the needles and mains.pilots are pretty much a givin,right around 50. also mess with the air fuel screw.your motor is only going to be ass fast as the guy tunning it and riding it

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every motor is different. we need to know your current jetting before we can make any recommendations. if youre running 35mm carbs now you should be able to use your intakes with some 39's should you choose to go that route.

 

my brothers 4mm cub right now has 45 pilots and 162 mains. needle in the middle. your setup should be close to that except if youre at sea level you may need to jet up just a little but more. figure out what youre running and well go from there.

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Ok thanks this thing just feels like a turd. sometimes i cant keep it down then feels like the clutches are slipping. i did move the clip up one notch a while back to lean it a lil. now it is one above the middle i believe. its so tempermental but i will get it right with yals help hopefully soon.

 

and yea zac i kno lol... i will give you a call sometime today or so...

 

thanks... :confused: :shoothead:

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im at sea level and run 162 mains and 50 pilots on my 35's, its a tad on the rich side but thats how i like it..... i hope u get it figured out man, I know the frustration all too well......GOOD LUCK

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im at sea level and run 162 mains and 50 pilots on my 35's, its a tad on the rich side but thats how i like it..... i hope u get it figured out man, I know the frustration all too well......GOOD LUCK

 

i just checked mine it has 155 main in it not sure the pilot didnt have a lil enough screw driver lol. but the needle clip should be one above the middle. should i try more timing? what would how much do? its topping out too fast. but it pulls good when its running good. should i try a 16 tooth front sprocket? anybody got one? so theres my main jet what can i do to get more top end?

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every motor is different. we need to know your current jetting before we can make any recommendations. if youre running 35mm carbs now you should be able to use your intakes with some 39's should you choose to go that route.

 

my brothers 4mm cub right now has 45 pilots and 162 mains. needle in the middle. your setup should be close to that except if youre at sea level you may need to jet up just a little but more. figure out what youre running and well go from there.

 

it has 155 mains in it and if i remember correctly i moved the clip up one from the middle cause it seemed a lil rich. what could i do with timing? anything that would benefit it? how much would do what? i would love to run 39's if i could trade somebody outright for my 35's i would. same goes for shearer's... should i try to go to a 16 tooth front sprocket? i tried a 17 didnt like it at all. it was too much. it hooks good but tops out too soon runs out of power too fast like the power band is too short or smtn not quiet sure its so frustrating. i might just go run the shit out of it real quick :evil: :mad: lol

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no i run 15/40 now tried a 17 it was too high didnt like it took too much from bottom.

 

no i havent done a plug chop i usually run 111 when they dont have that i get 100 octane. my plugs look good tho. but yea it seems to get weak on top end in lower gears like it could have more pull all around smtn is def not right.also never have done a compression test. i think im gonna try +7 timing just for the hell of it. its hard finding time to work on it and trial and error it. and run it and all. thats why im trying to get all info i can from yal thanks for all yals help keep the info comin please. i need direction lol. not sayin it runs horrible tho cause it does run good sometimes some situations. but ill mostly be dragging it and hill climbin kinda goin for smtn like LOCOGOTO's setup.

Edited by POORBOY350
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