Bore diameter ?

Sibbo · Post by **Sibbo** » Mon May 04, 2015 5:33 am

I just measured the bore of my ST at 84.8mm is this standard or oversize ? I have to order rings, preferably the right ones .

ME 109 · Post by **ME 109** » Mon May 04, 2015 6:35 am

Don't you have nikasil cylinders Sibbo?

If so, one size fits all. There is no oversize.

Sibbo · Post by **Sibbo** » Mon May 04, 2015 7:05 am

Oopps ! You're right I was looking at this .

50391
Part No.50391
BMW Part No.
11 25 1 335 218
PISTON RING SET,800cc R80/7 (+0.25mm) 1ST O/S
(PER PISTON)

ME 109 · Post by **ME 109** » Mon May 04, 2015 7:27 am

Sibbo wrote:Oopps ! You're right I was looking at this .
50391
Part No.50391
BMW Part No.
11 25 1 335 218
PISTON RING SET,800cc R80/7 (+0.25mm) 1ST O/S
(PER PISTON)

That's for the old bikes, not ours.

How's the original cross hatching in your cylinders?

Sibbo · Post by **Sibbo** » Mon May 04, 2015 8:00 am

It looks pretty good but the rings are shot, a bit of carbon on the pistons but nothing dramatic, just tired .

New needle and jets too.

Major Softie · Post by **Major Softie** » Mon May 04, 2015 11:49 am

Wow, compression, oil scraping, AND correct mixture? It's gonna be a whole new bike!

Sibbo · Post by **Sibbo** » Mon May 04, 2015 5:50 pm

30% more horse power would be good !

Boxerworks.com

Bore diameter ?

Bore diameter ?

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Re: Bore diameter ?

Re: Bore diameter ?

Re: Bore diameter ?

Re: Bore diameter ?