New Build with pocket bike motor

GoldenMotor.com

ZnsaneRyder

New Member
Nov 21, 2008
163
0
0
FLORIDA
Same here, excellent job on the bicycle! I bet a high revving 49cc pocket bike motor will smoke any 49cc or 80cc bicycle motor!

I've seen a 46cc Goped engine that can do over 55mph, (Craig's bike) so I'm curious as to how the pocket bike engine compares!
 

toker_ace

Member
Oct 15, 2008
476
2
18
alabama
My brain is going ...............Round n Round n Round n Round! Pocket bike motor ...yea,yea,yea .....YZ 250, Cr500, ...............Jet bike Yea! Details! .xx.
 

old motorbike

New Member
Sep 21, 2008
352
2
0
78
Fl.
Thanks to everyone for your kind reception of this idea. A while back, I saw a small 4 wheeler being tested nearby where I work. I was awed by the performance of the little engine and saw it replacing my China Girl.
I found one on my favorite store, E bay. $61.00 + shipping. I had to have it. China motor II is smaller, lighter and looks better quality. I found the correct chain size on a scooter parts sight and ordered a chain and the biggest rear sprocket I could get, (also inexpensive)

Went to work making a mount for the engine. With 1/2" square tubing from Ace hardware and 1" x 1/16" band iron, I bent and welded (with a wire welder from Harbor Freight) the frame to clamp to the bike using an aluminum plate to mount it to the engine.

In between, The China girl went back to the original bike, So I could ride more.

I've been swapping work with a bike shop owner for bike parts for this. I got a rear wheel with a disc brake mount and adapted the sprocket to it. It must be geared too high, But I'll find out.

Guessed on an exhaust for a pocket bike on e bay. Cut and re-welded it to fit. Just finished it tonight.
Also hooked up new throttle and kill switch.

Got home tonight and the gas tank was just delivered.

Maybe this weekend??!!

More pics later.shft.
 

sojudave

New Member
Oct 18, 2008
189
3
0
austin tx
Are you using #25 or 8mm chain? I saw an engine like yours on ebay and I was wondering where the mounts are. I was also wondering what you use as a rear sprocket? If you're using a pocket bike sprocket, how did you mount it to the rear wheel?

thanks for your time.
 

Dan

Staff
May 25, 2008
12,765
115
48
59
Moosylvania
Thanks to everyone for your kind reception of this idea. A while back, I saw a small 4 wheeler being tested nearby where I work. I was awed by the performance of the little engine and saw it replacing my China Girl.
I found one on my favorite store, E bay. $61.00 + shipping. I had to have it. China motor II is smaller, lighter and looks better quality. I found the correct chain size on a scooter parts sight and ordered a chain and the biggest rear sprocket I could get, (also inexpensive)

Went to work making a mount for the engine. With 1/2" square tubing from Ace hardware and 1" x 1/16" band iron, I bent and welded (with a wire welder from Harbor Freight) the frame to clamp to the bike using an aluminum plate to mount it to the engine.

In between, The China girl went back to the original bike, So I could ride more.

I've been swapping work with a bike shop owner for bike parts for this. I got a rear wheel with a disc brake mount and adapted the sprocket to it. It must be geared too high, But I'll find out.

Guessed on an exhaust for a pocket bike on e bay. Cut and re-welded it to fit. Just finished it tonight.
Also hooked up new throttle and kill switch.

Got home tonight and the gas tank was just delivered.

Maybe this weekend??!!

More pics later.shft.

Awesome OMB!!!

(can you post a link to the seller? I want that GB yesterday!)
 

old motorbike

New Member
Sep 21, 2008
352
2
0
78
Fl.
Just installed gas tank and tried to start, No spark. Took out mag coil and re-spaced it and it started and ran great. The gearing was way too high. I could barely get it going, but it did well, then stalled. After about 3 pulls the pull start broke (chinese plastic).
So I stopped for now. I'm getting a new metal pull start and looking for a way to gear it down, maybe a jackshaft or another gear reduction added on.
the gear reduction is about 3:1 and final chain is 5:1. So I need about another 10:1
 

lovehamr

New Member
Oct 9, 2009
24
0
0
GA
Just saw this thread and iuf you're still working on the gearing you might call the manic mechanic. He has the patern for the ISO disc mount and could probably make you whatever size sprocket you wanted. I think the gearing is totally fixable w/o a jackshaft.

That be said; how have things gone with the project since April? In these pics it's quite clean!

Steve