DIY Pit Bike 49cc Engine

MikeBike

New Member
Oct 7, 2008
145
0
0
Palm Springs CA.
what up all you DIYrrss.

i got questions about mount a avrage pit bike engine to a 26" mt bike.

Pocket Bike Parts > Complete 49cc Engine with Transmission

theres the link,

right off hand i can think a new sprocket and a mount, i have a design in mind,

but mainly i was wondering if any of you have done this, or has dimensions of this engine. i no i am going to have to mount it higher then the pedals.

any ideas?

i really like this engine. i dont know why.
 

stude13

New Member
May 28, 2008
404
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0
north bend wa.
not all are. i have a lifan lhd and i have five pocket engines which are rhd. rhd's generall need a jack shaft to apply power to lhd sprocket. is what i meant.
 

MikeBike

New Member
Oct 7, 2008
145
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0
Palm Springs CA.
no no hushing here, i want your in put.

i was thinking about mounting it above the pedals. but do you think it would be a problem in trying to reach the pedals becuz of how ide it is?
 

ocscully

New Member
Jan 6, 2008
373
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0
Orange County, CA
no no hushing here, i want your in put.

i was thinking about mounting it above the pedals. but do you think it would be a problem in trying to reach the pedals becuz of how ide it is?
There are wide cranksets available from different vendors that can get the pedals out far enough to clear most set-ups. Of the kits currently available the widest are the 4-strokes that use the HondaGXH50 or its clone from china. This motor with its reduction gearbox attached measures in about 8&3/4 ins. wide. The motor and gearbox you have linked to I believe is close to 11&3/4 ins. wide. There is a new set of wide 3-piece cranks from Grubee that have a bottombracket spindle that measures 9&1/4 ins. long and then you still have the additional width added by offset crank-arms. It may provide enough width to clear the motor above.

One other area you may want to address: I believe that most Pitbike motors and the one shown above use #35 chain rather than the #41 used in most motored bike drivetrains. You may want to explore the availability of rear driven sprockets for #35 chain and how you will mount them to your rear wheel. There was a project awhile back elsewhere where someone rackmounted one of these motors and gearboxs. This person changed the output sprocket on the gearbox to one compatable with #41 chain make everything work.
 

comfortableshoes

New Member
Jul 22, 2008
606
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0
Beverly, MA USA
damn the government and their silly laws, getting in the way of shear fun....

that being said you MAY be able to put extra wide cranks on your bike, and then bend them, it'll look funny but will get you to the requirements....


there's a post on here somewhere about someone who bent their cranks with a torch and a pipe... can't remember who though...
 

Caus-I-Can

New Member
Sep 15, 2008
21
0
1
Hi De Hi been readin and i use exactly the same pit bike engine that you showed in the link, only thing is i have a slightly different gear box (although i does appear if it would be the same gear reduction) and the cog size has only 13 teeth.

some probs i had mounting were geting the chain up the inside of left hand wheel strut that comes from the seat post and gaining enough clearence for bounce/movement during riding.

i have used it and so far done around 600km with no engine problems
it gets me up to 47/8 km/h on a 20" rear tyre with 72 - 11 gearing

should be able to get chain and rear sprocket from same surpplier i'd imagine

had to modify rear sprocket to fit rear hub but i bolted it on by removing three spokes
and slightly enlarging holes to accomidate bolts


if you decide ti go with this engine get in contact and i have heaps more info/tips
 

MikeBike

New Member
Oct 7, 2008
145
0
0
Palm Springs CA.
Hi De Hi been readin and i use exactly the same pit bike engine that you showed in the link, only thing is i have a slightly different gear box (although i does appear if it would be the same gear reduction) and the cog size has only 13 teeth.

some probs i had mounting were geting the chain up the inside of left hand wheel strut that comes from the seat post and gaining enough clearence for bounce/movement during riding.

i have used it and so far done around 600km with no engine problems
it gets me up to 47/8 km/h on a 20" rear tyre with 72 - 11 gearing

should be able to get chain and rear sprocket from same surpplier i'd imagine

had to modify rear sprocket to fit rear hub but i bolted it on by removing three spokes
and slightly enlarging holes to accomidate bolts


if you decide ti go with this engine get in contact and i have heaps more info/tips
WOW thats soo great!!!
45+ on a 20" tire and a 50cc engine, thats pretty good!!!(^)

do you have to pedal or do you have enuff torque just to take off?

is it ockword to pedal?
how much moding did you do to the muff to fit it on a bike?
was it a PAIN to do? how about pics?
man i have to many questions.
i am so intrusted .