Nikasil Coating

[deonattard]

Can anyone tell me of the bore in the TR280i is Nikasil coated?

In the parts book, there is 4 different piston kits:

6612020211--A

6612020211--B

6612020211--C

6612020211--D

I presume these are over-size options which suggests to me the bore is not coated?

I thought all modern bikes would be using the coating but the piston options have me doubting that.

[lineaway]

All the manufactures show over size pistons. I doubt any use steel liners that are boreable.

[goudrons]

You'll find the bore is coated (Nikasil) and not reborable (is that a real word??).

The pistons are listed in increasing sizes, A, B, C etc as one is microns bigger than the next, so instead of replating everytime the bore/piston wears, the next piston can be fitted until D, then it's a recoat back to the A piston.

[gasgas249uk]

All the manufactures show over size pistons. I doubt any use steel liners that are boreable.

Deon , Oversize pistons are available for nicosil bores. Its not unusual ,but hardly worth the faff.

Edited May 22, 2012 by gasgas249uk

[deonattard]

Ok - is there any guide to understand at which bore measurement do you goto the next piston size? Or do you just change to the next size up each time the piston is replaced?

The manual says to do the piston and rings at 60hrs, has anyone done a pull down at 60hrs and if so, was it worth changing?

[goudrons]

I've not seen the manual, but they usually say these need checking and measuring at certain intervals (your 60 hrs??)

If they are past the tolerance then it's time to look at either fitting one of the larger pistons to retain the correct clearance, whether that be a B, C, or D

or

If these are still not big enough to do that, replate back to A piston size. Though often it's replated to whatever size piston is available at the time!

Each manufacturer will set these tolerances, most are fairly similar as pistons are of similar manufacture, but if these measurements aren't in the manual, it's either the dealer or importer that will know.

I reckon you'll find most will run it until it's shagged on that piston and bore, then slag the model off for poor performance, then buy a new piston and replate!!