Engine sound decel

[mrkartoom]

As I mentioned get the cylinder cross-hatched with a ball hone to clean it up nice and help the new rings seat in. Good luck!

[NSE.ONE]

Really??
I would have thought that would destroy the Nicasil(SPL?) coating on the bore.
Its not something ive ever done, im no expert, but my bikes have always kept going.

[noobi]

Iv never heard anything good coming of honing a nikasil bore, the coating is sooooooo thin that the bore would take almost all the coating off.

[Jakobi]

yeah everything I have read indicates if the cross hatching is all but worn away its time for a new coating. If not clean it up with scotchbright and continue on.

[GMP]

I think the ball hones might be a bit rough on the port edges. Some use them successfully I'm sure. I've used one on a 4stroke and it worked well, but maybe too well for a ported cyl. I use a tool that has a stack of scotchbrite discs on a mandrel. Works OK in cleaning things up but will not touch the nikasil.

[gasgasman]

I've used the ball type hone several times without any problems.
You just have to give is a couple quick blips up and down the bore. Basically, knocking the glaze off.

[mrkartoom]

The Nikasil is hard and as gasgasman says all you are really doing is knocking the glaze off with a couple passes in the bore. This helps the rings seat better. I refer to all of the tools as ball hones, but in reality the tool has the little plates with whatever the abrasive is. No damage to the coating. I've never re-ringed a bike without swinging by the shop and having the cylinder "de-glazed" and re-hatched. Use to re-ring my RM125's 2-3 times a season and never had a problem.

update: I talked to my shop and they use the ball (flex) hone on the 2T's. The spring-loaded finger types are not used on the ported cylinders, as those can catch up on the ports and do damage as mentioned. Basically just re-introduces the oil holding cross hatch pattern and doesn't harm the coating.

[Jakobi]

Well everythings been ordered.

S3 Head with 3 inserts. Should bring squish back to around 1.4mm from what I have been told.

Going to lift the jug till the exhaust port and piston are level at BDC and maintain compression and squish by using the head insert that puts me where I want to be.

Should be a happy Gas Gas with a fresh piston and rings and a few small changes. Hopefully the N3EW needle will be here by the time I have it rebuilt and it will be all go again!

[Bailey28]

You know you are going to have to try every needle you own in the damn thing again!!

Can't wait to hear the results of the S3 head and inserts, you may need to order a rear fender as a spare just in case you blip the throttle a 'lil too much.

[Jakobi]

I hope not Bailey

I think the N3EW will be right on the money. I'm hoping that it doesn't end up using too much fuel as I've been quite happy with the economy I have been getting with my current jetting. About 6L for 70km mixed open and single.

Quick question. When I measure the squish the RB guide says to turn the engine over with the flywheel. Does the gasser run a gasket for the flywheel cover that will need to be replaced?