Man am I cheap.

Thereparist

New Member
Joined
Jul 19, 2018
Messages
13
Hello everybody, I'm lookin to get my motored bikes fix. Issue is, I'm not exactly rolling in dough. My plan, was to get a Harbor Freight 79cc engine and slap that baby on a bike. Then I learned about the jackshaft setup. I spoke with someone and they told me this was neccesary. The problem with this was that its expensive. So now I'm at a loss. I was planning on going with a CNC sprocket hub, so things have been planned out on that front, but I need a solution to a clutch. Help!??
 


FNTPuck

Well-Known Member
Joined
Jul 2, 2018
Messages
394
The jackshaft not only gives you proper gearing ratios, but brings the output sprocket closer to the rear sprocket line. Without one, on a stock bicycle rear the engine shaft sticks out too far to line up with the chain unless you mount the engine way hanging off the right hand side.
 

mark20

Active Member
Joined
Sep 26, 2018
Messages
392
Hello everybody, I'm lookin to get my motored bikes fix. Issue is, I'm not exactly rolling in dough. My plan, was to get a Harbor Freight 79cc engine and slap that baby on a bike. Then I learned about the jackshaft setup. I spoke with someone and they told me this was neccesary. The problem with this was that its expensive. So now I'm at a loss. I was planning on going with a CNC sprocket hub, so things have been planned out on that front, but I need a solution to a clutch. Help!??
well, what tools do you have? (ie do you have/know a guy with a welder? do you know how to weld? how much $$ we talking etc)
my bike has a 97cc engine and i still use the rag joint, zero problems with it, but your mileage may very.
and yes a jackshaft is really necessary, i tried running mine without one to realize theres NO bottem end. i couldn't even accelerate, i used a jackshaft from a baja warrior.
and if your on a budget, why not just get a CG engine? there under 90$ for a complete kit and they run great! (you just have to break them in correctly, and run 32:1 afterwords)
thats the route i would go personally, yes theirs problems with them, but if you mechanically handy, there no biggie heres what my bike looked like before the 97cc engine, its a standerd CG.
86668

and heres it with the 97cc engine, believe it or not, the CG was faster by 2mph lol
but the 97cc engine is cheaper to run (only get up to 3K on the tach, runs like a diesel lol)
20190322_155815.jpg
 

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mark20

Active Member
Joined
Sep 26, 2018
Messages
392
Thanks for the suggestion, but I almost feel more comfortable with a four stroke. Had some run ins with 2's in the past.
Ah I see, not a fan of top end rebuilds ;)
Well, then I would go with a Chinese hasuenge 53cc 4 stroke kit (there like 189$, the whole kit with the engine! Try to get a belt drive transmission, there a better deal in the long run, even if there a bit more pricey)

Good luck on your build!
 

Thereparist

New Member
Joined
Jul 19, 2018
Messages
13
That's not to say you haven't piqued my interest, however. Tell me more about this CG kit. 97cc sounds a bit too good to be true for a small 2 stroke.
 

mark20

Active Member
Joined
Sep 26, 2018
Messages
392
That's not to say you haven't piqued my interest, however. Tell me more about this CG kit. 97cc sounds a bit too good to be true for a small 2 stroke.
No, that's the size of my 4 stroke bike engine lol.
The CG is a 66cc engine, still plenty for a average Joe (some people have gotten nearly 16hp with these, but that requires a hella lot of modification)
There very cheap, and some are better than others (I've had around 1800 miles on my engine before I swapped it, still runs perfect too)
You can get the whole kit for around 90$ and you can install it in a day. Very fun to ride as they have a real dry clutch!
 
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