16" pit bike

GoldenMotor.com

LS614

Active Member
Dec 22, 2009
1,236
3
36
CT and MA
I went to an estate sale on Saturday and found a working homelite ST-80 string trimmer for $4. The engine is very well made and powerful. It is made no later than 1986. I wonder what I should do with a powerful little engine LOL! A motorbike perhaps. I was thinking of making a homemade pit bike with a child's 16" bicycle by extending the seat post and raising the handlebars (ape hanger style) I was then planning on doing a grinding peg friction drive. Has anyone ever modded a little bike like this before? Please give your comments and suggestions. I'll post pics asap.
 

LS614

Active Member
Dec 22, 2009
1,236
3
36
CT and MA
that's exactly what I thought WHY NOT?
I don't want to commute with it, just have a toy that I can beat around
again, pics up soondnut
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
6,537
264
63
living the dream in southern california
i want to motorize a little bike, too. i keep looking at those 16 and 20" "convertible" bikes from the 70's where you can remove the top tube to make it a girl's bike. i wanna do an in-frame kit with it.

but that's just one of those projects where i think, "that'd be cool..." and i never get around to it.

good luck with yours.
 

LS614

Active Member
Dec 22, 2009
1,236
3
36
CT and MA
Thanks!
Good luck to you too
An in frame would be cool, but I do not have the time or desire to work out a chain and clutch system for this quick and cheap build
I hope you get around to building your 16 or 20", I'd love to see how that turns out
 

bmxmotorbike

New Member
Mar 21, 2010
3
0
0
adelaide australia
i have done this before when i used to make whipper snipper bikes. its easy, i used a 33cc whipper snipper motor with a bmx peg welded to the shaft, made some breakets and welded it on a 16 inch frame.

like to see what pics u come up with of how you did it
 

TerrontheSnake

New Member
Jun 1, 2009
720
0
0
Oregon
LoL, I have also done this before. On a 16 inch with that size motor a Bike grinding peg is perfect actually it gives a perfect ratio for your friction drive. My old 40cc homelite on a GT dyno went 33mph and was scary then because at wot the front tire would lift of the ground every couple of seconds due to a the way the final revs would slighty fluxuate. Blew her up trying to haul down a hill I hit almost 40 when she blew.
 

Elmo

New Member
Sep 3, 2009
748
4
0
Mississippi
I have a friction drive Homelite and the engine is at least as old as yours. Check the cylinder hold down screws every now and then. If you run it wot all the time they can loosen. I have 639 miles on mine now.
 

LS614

Active Member
Dec 22, 2009
1,236
3
36
CT and MA
Thanks for the advice! do you have any pictures or suggestions on mounting the engine? If mine is anything like yours it doesn't have the 4 bolt holes around the shaft like the ryobis do Any pictures or advice would help
 

LS614

Active Member
Dec 22, 2009
1,236
3
36
CT and MA
Thank you for the picture, that might help! This engine is actually a full crank. I'll try to post some pictures to see if I can get any more advice. Still, removing the pullstart and using those holes gives me some ideas!
 

Elmo

New Member
Sep 3, 2009
748
4
0
Mississippi
The pullstart is on the end opposite to mine I think. On a full crank it is usually on the other end from the weedeater shaft. I hope that makes some kind of sense. Good luck with your build. One good thing about a full crank you can put a friction roller on without a bearing on the outboard side and they are usually a larger engine. Thats two things. LOL