Hyosung Sense SD50 - Where to find top end engine parts?

[vtpete]

Hi,

We own a 1999 Hyosung Sense (49cc) with about 5K miles on it.  Climbing power is not what it should be.
Transmission and carb are fine, but my compression is a measly 82psi.  I've temporarily started to use lighter rollers to help with slower speed hill climbing, but that's only a temporary fix.

My problem is finding any specs on alternatives for beefing up the top end.  A ring kit at a minimum; although I wouldn't mind purchasing a new top end - even installing a big bore kit.

After spending more than an hour online, I've only been able to find a single eBay listing for a new top end.

Does anyone here know where I can find replacement parts?  Or how about knowing if the top end is compatible with any other scooter brand manufacturer?

-Pete

[FrankenMech]

5K is past time to set the valve clearance. You should be able to download a service manual on this site. We also have links to videos on the subject. Links to manuals, videos, engine ID, etc can be found floating on the left side of the screen. Links to parts dealers can be found at the top of the screen and in our dealers section. Stay away from eBay parts.

[vtpete]

Thanks!
I have the service manual handy, but it doesn't give the specs on things like ring sizes.  What I *did* find was a part number (12140-29C40) that is also used by Suzuki.  (It's just a ring set.) My biggest issue isn't the work; that I can handle.  It's finding parts because Hyosung doesn't carry them any more.  I was hoping someone would say, "Oh, that engine is the same as a Suzuki XYZ", etc.
-Pete

May 17, 2023 11:18:06 GMT -5 FrankenMech said:

5K is past time to set the valve clearance. You should be able to download a service manual on this site. We also have links to videos on the subject. Links to manuals, videos, engine ID, etc can be found floating on the left side of the screen. Links to parts dealers can be found at the top of the screen and in our dealers section. Stay away from eBay parts.

[geoffh]

Post some pictures of the engine,check for an engine code stamped on the casings,139QMB would be a good result.

Geoff

[chadbullet]

I am of the understanding that the Hyosung Sense SD50 uses a Morini engine not too dissimilar to TGB. I'm not coming up with much as far as what bbk and exhausts are compatible with this, so proceed with caution.