Hi
Ok so hear is the story, tried to start the bike this morning, and it wouldn't start, checked the plugs were sparking and wet, and they were, (so getting gas and spark). after a while, it decided to refuse to tern over, so I took the barrels off and the pistons could be in better condition, so i am getting new ones and doing the top end. with the pistons off, the bottom end still wouldn't tern over with the kick, so i put it in 1st and gave it a push and it turned over, and then it would tern over fine with the kick again for a while, then it jammed, push in 1st and its fine again for a while.
So the questions:
1st does any one know what could cause the bottom end to do this?
2nd where is the best place to get pistons? also I am thinking (with no research yet) of boring it out to 300cc or something, does anyone know if there are after market pistons around that will do that? or if there are other pistons that will fit/work? maybe off the ns400r or something?
Thanks for you help

Also forgot to say, I have a MC11 NS250R, not a MC16 or up NSR250
thanks

Well, not knowing more about how it got to this point (I mean, did it run yesterday?, How did it run when you parked it?, etc.), but it sounds like you have a bearing that's packed its bags. If I had to guess I'd be thinking main bearing or big-end rod bearing.

Tell us more about the last ride.

RZ Rob
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Keep the Rubber Side Down

hey thanks for that.
It was running badly (its a lemon and always is) it was getting far to much gas (to the point where it was leaking out of my newly cleaned pipes) and smoking like a train. I had been having carb issues so i changed it for my spare, after that it wouldn't start as above. something i did think of last night though was that I had replaced the gearbox fluid when i took the pipes off so it was less than a week old and it had about half gone, when it seized i checked it and realised this and topped it up. It had not leaked out in the garage or anything either.

Econohonda in Te Aroha have a massive stock of new and used Honda parts. They have a big pdf file on their website which you can browse if you know the part numbers for the things you need.

I wouldn't bother boring it out, as soon as you start to play with things like that reliability takes a nose dive and the bike gets dearer and dearer to run. If you want more performance i'd recommend getting an MC21. Information on running them is much easier to find and tuning parts and genuine spares are easier to get. Plus its a newer, better bike all round.

If gearbox fluid is going missing it may be getting pulled into the crank case past one of the crank seals. It also sounds like you've got knackered main bearings as RZRob1 says.

It sounds like you need a new crank, left and right side crank seals and fresh pistons, rings, wrist pins, circlips, small end bearings etc. I'm not sure exactly what you need because i dont know how different your engine is to the MC21 engine.
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After years of moaning about immigrants now i am one...