New 80cc Install on Mountain Bike

jrnapsdb01

New Member
Jun 19, 2008
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Hello everbody,
I am new to the world of bike engines. Have been working on my 80cc mountain bike project for 2 days now. Chain still falling off, had to move all bike cables from under gas tank to sides of bar and reset and trim all cables. Have not yet experienced the first test ride due to chain problems. I was exicited to get the kit, but now am starting to get a bit frustrated...
 
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Dave31

Moderator
Staff member
Mar 1, 2008
11,204
29
38
Aztlán, Arizona
Welcome to the forum, glad you joined us :D

Are your sprocket's lined up ? Is the tension in the chain correct ?
You should have at least 1/2 inch of play in the chain.

Have any question's just ask, alway's someone here to help out.

When you get everything just right, you will really enjoy your motorized bicycle. I think most of us had trouble when we first started out...it get's better.

:ride2:
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
3
0
north carolina
Most of us had to remove a couple of links from the chain to make it fit. They send a little extra usually so you have enough. If that is the case and the chain won't get tight you need to just remove a couple of links then reinstall the master link.

When you install the master link make sure the clip is facing toward you not toward the r motor. If you need to remove chain there are a couple of threads to explain it. If you can't figure it out ask and someone will explain.
 

thatsdax

Member
Feb 22, 2008
869
1
16
www.thatsdax.com
Hi.. Welcome.. And.. For starters... There is no 80cc...

There is no such thing as an 80cc kit. The largest produced is a 70cc. If you bought from someone that says they are selling an 80cc kit, then.. Beware... As for your install. Do you have any pictures you can post? This would help us help you if you have any pics. Thanks.. Enjoy the ride...
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
236
63
up north now
Welcome....

Look down the top run of the chain from the rear...do the sprockets line up?
Is the wheel straight?
3/4" of play in your chain at the loosest part?
Tensioner running straight with the bottom chain run?
 

Ilikeabikea

Moderator
Staff member
Jan 27, 2008
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Ptown, Texas
Welcome to the forum. Like everyone else has said. Check your alignment. Make sure it's really straight. Motorized bicycles are blast once you get all the bugs worked out. Glad you joined us.........................
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
3
0
north carolina
Also I threw my chain a dozen times because my bearing nuts weren't tight. the wheel wobbled and I didn't know it.
 

jnothem

New Member
Jun 24, 2008
1
0
0
I too am new too motorized bikes... One thing I quickly realized is not everything goes the way as planned. Be patient, give it time. Take your time building and fixing the bike, that way you learn more about how things work.
 

drmike176

New Member
Jun 28, 2008
3
0
0
My issue has been dealing with the front motor mount and the larger frame. I just looked at the on line directions. I see to use longer studs. I was wondering if I could just ease the old ones out or this a pulling operation. thus threading the holes.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
236
63
up north now
The stock studs will just unscrew. They still won't (usually) ebwide enough to clear and there are several ways to get around that.
 

drmike176

New Member
Jun 28, 2008
3
0
0
I was thinking if i just do a little filing on the frame without putting stress on the frame this could work. Otherwise add some pipe to the frame that would fit. I looked at that over the weekend and did not like that system. Has anyone come up with an idea?
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
236
63
up north now
There are several ways....one is to run the stock mounting studs through a piece of plate steel and then drill holes outside and above or below those that are far enough apart to clear your frame, then fasten it to the frame with a muffler "U" clamp.