Other engines that will fit a CB100 or act as a top end donor

[KentuckyJelly]

Hi everyone! This is a great forum. I hope you can help me...

I bought a 73 CB100 that has seen better days. My mechanic and I decided it would be easier to get a donor engine to either transplant or rob for good parts.

My question(s): Are the XL100 and SL100 engines essentially the same as the CB/CL100 engine? Can a '75 XL engine be easily transplanted into the '73 CB100 frame? Or, can the '75 XL engine serve as a top end parts donor for the 73' CB100 engine?

Last question - is there a Lifan engine to replace the CB100 engine?

Thank you in advance!

 

[xb33bsa]

i am almost positive it is yes to all those the 100's were all identical the 125 only differs in bore size
ton's of info out there ,there must be a forum dedicated to that as well try thumpertalk

 

[CALfeRacer]

All the 100s, 125's, 175's, 185's and 200's can be put in that frame. The ones bigger than the 125 will need the mounting holes bored to 10mm to fit, but that's all. The 100 and 125 engines all should be a direct swap.
As far as the head for the 100, I believe the XL or XR had slightly larger valves, but all were the one piece head design. Later 125s had a two piece which I believe also had slightly larger valves.
Lifan makes a pushrod style 125 that should work, not positive what's different though (besides the obvious OHC vs pushrod). Erskine has a Lifan engine in his bike.
Hope that helped!