Big jugs

[Mouse]

I have a 48cc grubee Skyhawk 2 stroke can I change the jug and piston to a 66/80cc?†

 

[ckangaroo70]

Large jugs? Sorry...was expecting to see something different here. lol

Really don't know why you couldn't go with the larger displacement jug. I think the lower ends are basicly the same on most all the china girls and I would assume the cranks the same, but perhaps more research is in order

 

[Greg58]

The stud spacing is not the same, I don't have the specs but I do know my 48cc's and the one 66cc are different.

 

[Mouse]

Is there any one who could help me with finding a faster reliable motor ? I'd like to go35-45mph without going wide open on the throttle. And can I modify the existing motor to do that?

 

[Greg58]

There are a lot of modifications that will increase speed, porting done right is one. Adding a expansion chamber is another, changing rear sprockets from a stock 44t to something with less teeth will increase top speed but cuts hill climbing ability. If you do upgrades do one thing at a time, that way you'll know if what you did helped or hurt performance.

 

[Mouse]

What about a jackshaft and hooking it into the existing bike gears?

 

[Greg58]

Yes a jackshaft kit will help, here in Georgia a multi-speed moped is not legal so you might want to check your state laws.

 

[Chaz]

Mouse, getting a bike to do those speeds is not a problem. Doing those speeds safely is the real issue. You are asking for motorcycle performance from a bicycle, so that bike and all of it's components must be up to the task. I'm guessing that about 75% of your budget and efforts should go into building a solid bicycle foundation to bring it up to manufactured moped standards.

 

[Mouse]

Got a grinding feel in bike when motor is engaged. Bearing? Time to rebuild?

 

[sbest]

The stud spacing is not the same, I don't have the specs but I do know my 48cc's and the one 66cc are different.

6mm studs at 42mm for the 48cc.
8mm studs at 45mm for the 66cc.

Steve

 

[crassius]

Got a grinding feel in bike when motor is engaged. Bearing? Time to rebuild?

grease the bucking bar & check chain run while there

 

[ajanessetrovy4712]

Not trying to answer for Ben or Gary but last year all the Big Dawg races was on a .05 tree in 7.0

 

[Mouse]

Sometimes thinking is not enough. The remedy was rebuilding the clutch

 

[Mouse]

Is there any one who could help me with finding a faster reliable motor ? I'd like to go35-45mph without going wide open on the throttle. And can I modify the existing motor to do that?

Really disappointed that Gruber doesn't make motors any more. A Gruber was my first motor and I never had an issue. Since then only problems with every 2 stroke I bought . Now I have a gx120 I want to put on a bike with a torque converter. But I can't find just the torque converter like on the 212 predator kit that will line up with my back sprocket. Any advice on finding one?

 

[Mouse]

Grubee