Trail 70 Cylinder on a XR50R?

[RazBarlow]

Hey guys,
Just wondering if I can mount a Honda Trail 70 cylinder onto my daughter's (Yea well I ride it sometimes :-) . I can get ahold of a trail 70 cylinder and piston form an old early 70's bike.
They look the same.
Has anything changed ?
Just cious if it will work and if it will just bolt on. Do I have to do an head work ?
Thanks,
Raz

 

[Jasle]

I have never taken the ct70 cylinder and put it on the XR but i have put one on a Z50. The cylinder drops right on but is alittle tight in the case. it probably would have worked to dremel the case a bit but it did go together. The head would not work. The combustion chamber area is made for a 39mm piston and then you drop a much larger one on top and it actually contacts the piston. You can snag a head off ebay for a few bucks and then your set. I'm sure you could machine the 50 head to make it work but you will still have the smaller valves.

 

[RazBarlow]

OK so what can I do before that ?

My daughter wants more power. She is running a stock setup. What low cost mods can I do to settle her for awhile that won't have to be reversed once I get a big bore kit ?
I like mods I can do myself or make myself. I am a tool and Diemaker by trade so I have machining capabilities.
Thanks,
Raz

 

[Jasle]

machine the opening of the carb. a bigger dia carb breathes better. There are a few different pipes out there but someone was putting out a simple spacer for the stock pipe that was almost as good as the aftermarket pipes for only like $20. I don't remember who it was but I'll do some diggin.

 

[RazBarlow]

Did you happen to find the spacer ?

machine the opening of the carb. a bigger dia carb breathes better. There are a few different pipes out there but someone was putting out a simple spacer for the stock pipe that was almost as good as the aftermarket pipes for only like $20. I don't remember who it was but I'll do some diggin.

Did you happen to find the spacer ? Did this fit between the cylinder and the pipe ?
Thanks,
raz