Engine Trouble Can anyone help identify

[Mickey112233]

Hey y'all, I know from previous experiences I can count on the best advice and knowledge when ever I need assistance. I found this gem in a friend's garage and I would like to fix it up for the kids (they are age appropriate for a minibike). I found a SY marking on the cylinder near the base,also what appears to be 5D40B7028 stamped in left case, also the carburetor is mounted on the opposite side of the piston/cylinder,never have I seen such a thing

 

[DieselTech]

Hey y'all, I know from previous experiences I can count on the best advice and knowledge when ever I need assistance. I found this gem in a friend's garage and I would like to fix it up for the kids (they are age appropriate for a minibike). I found a SY marking on the cylinder near the base,also what appears to be 5D40B7028 stamped in left case, also the carburetor is mounted on the opposite side of the piston/cylinder,never have I seen such a thing View attachment 207711View attachment 207712View attachment 207713View attachment 207714

Yeah that's a case inducted pocket rocket 49cc 2 stroke. Does it have a 54mm clutch or 78mm clutch?

 

[Mickey112233]

Yeah that's a case inducted pocket rocket 49cc 2 stroke. Does it have a 54mm clutch or 78mm clutch?

It has a 78mm clutch , and thank you. Arer these engines common ,parts available ? The exhaust port has one broken thread hole.

 

[DieselTech]

It has a 78mm clutch , and thank you. Arer these engines common ,parts available ? The exhaust port has one broken thread hole.

Yes parts are cheap. You can buy a new complete engine for $100-$150 depending on how you order it.

 

[DieselTech]

This cylinder kit should fit it. Or for more money you can buy a big bore stroker kit.

 

[Chainlube]

Yea those were used on a lot of pit bikes, mini choppers, and other kids bikes. Was there a transmission with it?

Clean it up, probably the only thing it needs is a new diaphragm for the carb. And, a jog pipe.

 

[Will'smotobikes19]

Clean it up, probably the only thing it needs is a new diaphragm for the carb. And, a jog pipe.

They use a float type of carb not a pumper

 

[Will'smotobikes19]

If anything it will bolt to a rack mount kit or a friction drive or you could mount it on a 4 stroke mounting plate for in frame.

 

[Chainlube]

They use a float type of carb not a pumper

I have one of those here, it has a saw type carb, no float. What does @Mickey112233 say?

 

[Will'smotobikes19]

Here's one on ebay float type. I think these were originally ktm clones. On a pocket bike the tank is above the carb so no need for a pumper carb. It's possible some of the new ones have a pumper but just going by memory of when I had one it definitely had a float carburetor hooked up to the reed block. That motor fell off the bench and broke half of the crankcase and I only ran it a few times. The o.p seemed to be missing the pull start and the carb so I can't tell what carb it is.