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Top End Maintance....

Featured Replies

Hi Guys,

Well took your advice on the swing arm its now had all its bearing replaced and they all showed signs of wear.....

So while I am waiting for my local dealer to get hold of a few bits I could'nt get of the net I have stripped down the top end.

Not sure what I should be look for. The barrel looks to have some marks on it but I am not sure if they are bad or not!! Should it be unmarked and smooth?

Cheers

Andy

smooth and with minimal pitting, andy. any scoring could mean some bigger problems.

out of interest did you get your bearings from a sherco dealer or a bearing supplier? what was the prices like? I just recently changed mine and a dealer quoted

  • Author

The barrel seems to has some slight scoring so is it worth having it rebored?

Got my bearing for www.simplybearings.com very cheap approx

If there was not a problem to begin with, such as low compression or excessive piston slap, put ith thing back together and leave it alone! These things seldome fail! Note head torque is in Nm not FtLb, you will twist a stud if you are not astute! Wear is normal with use but not neccessarily a problem! :D

Hi copemech,

With a compression test. What PSI, Bar, or Kg/cm2 should you get?

Best of balance.

Neo

Somewhere near 150 PSI would be normal. However you get a better "feel" by pushing the start lever through by hand. They normally have quite a lot of resistance.

Other than that, you cannot just re-bore these things as they are Nicasil plated and a rework costs nearly as much as a new one. Slight honing is permissable if properly done, but a new piston may need to be fitted.

Most just install a new ring set to freshen things up unless there are other problems. :D

Hi copemech,

I was once told by a guy (who reckoned he knew a lot about Trials bikes), that you should change the piston rings every year (which I have never done). What's your thoughts on this?

Best of balance.

Neo

I tend to think it has more to do with how much you ride and how much you rev the crap out of it!

You could double or triple that interval for most clubmen without problem.

My sherco 2.9 is a year 2000 and I believe it still has the original rings. Maybe it is time for a new set.

You see what I mean!!!!!!

Why do you need a fresh top end to haul around the same old butt? :icon_salut:

So the compression test is the real decider??

Best of balance.

Neo

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