New guy with a lawnboy

[Lawn-boy]

Hey guys, i have started putting a 2 stroke lawnboy engine on my bike. Its around a 4 hp. Its all bolted together. The engine just has too much compression and the crank is slipping on the wheel. What would you guys recommend (without purchasing anything online) to use for a friction drive? If i put a bigger wheel type thing on the crank would it help? Once i get the drive train all solid i will shower thy mods down upon the engine...pipe..porting..etc thanks

 

[Happy Valley]

Hi there, good start. A second brace on the left as well to hold steady down pressure might be a good idea. Drive spindle size affects gearing, larger spindle more top end but lower torque for climbing. BMX pegs can be adapted.


ps
you might want to downsize your pics.

 

[Hawaii_Ed]

wow, cool homebrew! I have no idea what to tell ya on the drive, but be careful not to get your shirt tail in that flywheel LOL!

 

[Mountainman]

nice
would like to watch this one come along
many have used a skate board wheel for the friction
some take something like what you have and make an epoxy mixture with sand mixture added
MM

 

[Lawn-boy]

Well a bigger drive gear would cause the engine to turn over easier ,correct? Im sure this engine has more than enough oomph to to push along at low speed without trouble.

 

[Esteban]

Be advised,,, that's a LOT of motor for a bike ! TOO much, in MY opinion.
But, if you insist, I agree, a brace on the other side is absolutely a must. It having so much power, you will see that overrevving IS going to make the drive roller slip. Maybe make a throttle stop to keep the rpm's down. You can buy a cheap grinding wheel, like you add to the end of your drill, put it on a table, wear safety glasses, cover grinding wheel, & beat it with a hammer. Take the fine powdered bits, & mix with JB Weld. Apply A LIGHT coat to the driveroller to get a better grip. Save remaining bits, for another coating later. It will take a little trial & error to keep from grinding the tire up too much, but you will get it.

 

[Mountainman]

Well a bigger drive gear would cause the engine to turn over easier ,correct?

larger friction drive wheel - makes for higher gear - faster top end speed
not the best for slower speeds
not the best on hills

turn over easier ?? not really

MM

 

[Lawn-boy]

Almost no hills where i am. It would make it turn over easier, its just like a motorycle, if you try to push start a cycle in low gear its hard to get the engine to turn over, shift it into a higher gear and it spins over a lot easier. I own 3 dirt bikes and ATC's so i'm fairly experienced with the engines.

 

[RMWdave]

word on the easier starting<bigger wheel.

i used to bump start my old tri-moto in 2nd

 

[Member 5549]

I wonder

If you can just put the rope pull back on and start it that way ??
most rack mounts use the starting rope....