mini bike Jack Shaft ?

#1
ok guys I picked up a verry cool looking well built Mini Chopper last year it has just been sitting . so this winter I want to get her running . it has a Honda 125cc steet bike engine on it . it has a jack shaft set up . I am a gokart guy . so my question is . i want to remove the 125 shifter engine and run a clone , big block or small block have not desided yet on engine size . . so can i just remove rear wheel & gear and flip it over and run just a straight up clutch and chain set up . i know it will be long . as this chopper was built by the Auto shop instructor at a area High School . it has some actual Harley donor parts on it , the bike is over 8ft long . gotta head to church i will post a pic or 2 later today
 
#2
i know i will need to change up the rear disk brakes . but shouldnt i just be able to flip the rear wheel and move the rear drive sprocket from the right side of chassis to the left side ? and build from there ?
 

125ccCrazy

Well-Known Member
#3
I don't see an issue as long as the clutch and wheel sprocket line up..if you have an excessively long chain I'd use a tensioner to prevent chain slap.. any reason not to use the jackshaft?
 
#4
I don't see an issue as long as the clutch and wheel sprocket line up..if you have an excessively long chain I'd use a tensioner to prevent chain slap.. any reason not to use the jackshaft?
no real reason just dont care for the extra rotating parts . just wanna keep it simple
 
#5
Mike I would run the jack shaft before I would run a Long ass chain . The jack will hold up to just about anything you throw at it . I have put stupid HP at a bonanza jack shaft and not really hurt it so far , just twisted a 420 chain a little .
 
#6
Mike I would run the jack shaft before I would run a Long ass chain . The jack will hold up to just about anything you throw at it . I have put stupid HP at a bonanza jack shaft and not really hurt it so far , just twisted a 420 chain a little .
dave aside of 35chain used in karting applications , i dont know if i can get the rite pitch driver for my clutches
. would you run a gear from engine crank to J/S and clutch on the drive side ? . that is my problem . i dont know if shaft is long enuff to fit the disk/drum clutch . the bike is inside enclosed kart trailer at this time . i will get some pics on soon . well maybe i can copy & past em from F/B
 
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#11
Hey Mike, :wink: If you don't want to shorten tha frame, maybe move the engine back..say at to center of the frame and use a jackshaft.
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35 chain set up will be fine for a small block app. :thumbsup:
 
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#12
Hey Mike, :wink: If you don't want to shorten tha frame, maybe move the engine back..say at to center of the frame and use a jackshaft.
......................................:001_tt2:..........................


35 chain set up will be fine for a small block app. :thumbsup:
was kinda thinking Briggs Vanguard:punk:
 
#14
Hell yea V twin . There a guy on here square chopper he put one on a Baja minibike , looked bad ass .
yes i think i have a line on a V-twin in S. Illinois for the chassis , it has alot of room in there . hell i think i could stuff a 900 sporty engine in it really if i tried hard enuff !!!!
 
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