How goes my like minded distant friends?

well since i last posted anything i have bought myself a couple of new bikes.

still ty`s but now i am the pround owner of a ty 250 pinky and a ty 80 small wheeled for my son.

However there is a problem. the pinkey has the loudest clattering engine i`ve ever heard.

i still have alot of power, alot more than the 175 i`ve been riding, it certainly does put a smile on my face even now as i write this post!

So anyway back to the point.

does the clattering engine mean that i should need to replace the piston and rings and then rebore?

And if so where would i send it and how much might it cost?

i look forward to your respected views and replys

andy bone.

1st thing is to remove the cylinder head and barrel then check the ring gaps. Then check for piston slap marks on the front and back of piston and barrels. If the piston is skuffed then there is too much play and a re-bore will be needed. If its smooth you can put the piston in the bore and check clearence between piston and bore and if excessive (check manual for tollerences) = re-bore.

If its OK then you may get away wth a set of rings but also check for small end wear and big end wear as this could also be a problem

Dave

another thing worth doing take the flywheel off and check the timing marks on the stator plate and

engine case line up!

Andy if you have some feeler gauges the maximum wear is 4 thou, (measured at the lower part of the barrel) any more and it needs a re bore. Scrape the carbon off the top of the piston anf it will be stamped .25, or .5 or .75. there are only 3 oversizes available so if its on .75 you can either get it converted to 270cc (ring Birketts) or get it re sleeved.

You need to find somebody you know will do a good job for the rebore or you'll be no better off after its bored. You need to get it bored to 1 thou clearence of the piston and then run it in very carefully. try your local bike shops, if not Birkett is your man in my experience.