my 2003 Sherco 250  is hard to start after about an hour of riding, stop starting at a trial. Its been happening alot more over the past 2 or 3 months. I was told when I bought the bike(but no receipts) it had a top end done before i bought it about 4 years ago. Im thinking Crank seals maybe on the way out. Are they an easy engine to rebuild? Ive rebuilt my Ty250a a couple of times, so its about on par with that?

Cheers.

 

 as an add on: I have cleaned out the carby time and time again, new airfilter, checked the float height as well.

Edited October 9, 20169 yr by wombat

If your crank seals are going, then you will be loosing oil from the gearbox. It would be very smokey.  Measure your gearbox oil in and out.  Crank seals don't require an engine rebuild.

 

You can have a worn seal on the magneto side and not lose gearbox oil.

replace spark plug at the first signs of hard starting and gap at .6mm

ill try the plug first and see how it goes..thanks all.

and check your ignition before. Hard hot starting can be due bad coils.