Honda SL125 Engine Out, Sized Piston and Barrel Removal

Not too bad, may not have to split the cases.

[@christopherronan4373]

Cracking video Brian,I love your methodical and logical approach to this rebuild.

[@TheCADengineer]

Thanks for your positive comments, Regards, Brian.

[@bsa_brummie7775]

That's a good start no horror stories. The bike overall has not been butchered by someone with a 2lb hammer. You can never really tell with USA imports this one looks ok so far 👍. I like the adaptor to ease the gudgeon pin out nice job.

[@TheCADengineer]

Luckily the crankpin and conrod have survived, so don't need to split the bottom end.

[@juleswatt3248]

very enjoyable episode Brian! I have a particular interest as i am currently rebuilding my stripped down SL100K1 1971 wirh full as i can refurb. My engine is siezed ( yet to come onto this side of the repair / rebuild work) i believe there are quite a few similarity's between the engines would you say? Bit nervous of the engine strip down as never attempted this before but hopefully all will end up back in the same place and i will repair the problems as i find them! As for finding the parts now thats a different story 😮😮. Thanks for the inspiration Brian. Jules

[@TheCADengineer]

@@juleswatt3248 Hi Jules, lt looks like all the running gear is exactly the same between the 100 and 125, however the engine top end is different, but not just the bore (stroke is the same) but it looks like the cylinder head has smaller valves. The big bore cylinder and piston kit has just turned up and the barrel doesn’t fit so l have just had to machine the barrel to fit the crankcase. Next job is to modify the piston which l will be looking at tomorrow. Hopefully l can machine it to miss hitting the inlet valve, but l have ordered a standard barrel and piston just in case l can’t get it to fit. The video will be up in the next day or so to show success or failure, hopefully a successful result. Regards Brian