New member, Reteck Cheetah, and a few questions.

Greetings from Michigan.

About a year ago I got my hands on the rolling chassis of a Retek Cheetah. It was found on the side of the road, being tossed out with the rest of the trash. It was picked up and given to me and I spent the summer tracking down an engine, clutch parts and other bits to attempt a restoration. Not an easy task since I can find almost literally no info on the bike.
I think this is a 250 cheetah since it had the chrome gas tank.
The motor I found for it is a 7hp tecumseh snowblower engine, which is a bonus because I was able to install an electric starter after all these photos were taken.
I found the original tires are no longer made so new ones were bought..they are an inch taller but they fit...barely. (you should have seen the look on the guys face at discount tire when I told him the huge tires were for a minibike.)
The original tank is beyond my ability to repair the rust damage, so a different tank was used.

Now come the questions.
The brake..(if you can call it that..) is a joke. So I am wondering if there is a kit or something to install a hydraulic brake? I'm not at all picky about keeping it original.. I just want the bike to be safe.

The current exhaust is comprised of some plumbing pipe screwed directly into the engine block. It does not matter how tight I try to screw the pipe into the block..once the engine gets hot and the metal expands, the pipe comes loose and starts moving. What can I use instead of the plumbing pipe that won't come loose?
You have a nice bike there. Can't believe someone tossed that with the trash. Try a jamb nut on the nipple to lock it against the block. They're used on conduit pipe to join to a metal work box. OMB member chatten 63 was repoping the clutch covers a while back. You may want to check with him. Also, member leathernun666 installed hydraulic brakes on his Retek...he may be able to help you. I have 3 of these bikes and you're right, very little info available on them. Good luck.