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1970 CL100 Cafe Project - Bore Information?

10417 Views 31 Replies 10 Participants Last post by  monkey
Yo! Sorry if this is a subject that's been covered already. I'm new to the forum and couldn't seem to find anything. So! I bought a 1970 CL100 back in July from the second owner, who bought it back in 1973. He used it sparingly, but maintained it well until about five years ago,. It has sat since then. I stripped the bike to a motor and a frame, and all seems straight forward thus far except for the motor. Given the scooter-esque displacement, I'd like to add a little more get up and go, while simultaneously getting rid of any compression problems that may or may not be present. So, hey! Let's just bore it, right? BUT... I have no idea what the best compromise between sustained reliability and performance may be... I've heard of people boring the cylinder to fit a 750 sleeve and piston, and that it's extremely reliable, the only difference being that the 750 piston requires a 15mm wrist pin rather than the 14mm in the 100. That can be reamed, correct?

But is that even the best option? What would be the displacement, horsepower, and performance gains on this? Would anyone happen to have firsthand experience with doing such a modification on this bike? Any and all performance/reliability tips would also be greatly appreciated.
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I get what you are all saying and agree with most of it. It will still be a small cc Honda and the OP doesn't know a lot, but that doesn't make it impossible. There are a ton of people messing with Honda single motors and chinese clones. Trouble is that few if any of them hang out here.

Start searching for Honda 100 pistons and pit bikes and TBoltUSA

Took me 2 seconds to find a stock type replacement piston CB100 | SL100 | CL100 | XL100 Piston Kit

There are forums full of guys playing with similar bikes if you do the research. Finding parts that will work in your motor is not as easy as for modern motors but the information and possibly parts are out there, but you will have to do the work to find it. Good luck - life is one long learning experience. Enjoy the journey.
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