Ring Gap.

[jmmmrm]

I have a 1995 900 ss (944) and I have the engine apart to ship off my heads. While it is out, I want to check the ringe gap and was wondering if anyone knew what the gap should be for 1) The gap of the ring while on the piston and 2) The gap of the ring off of the piston and in the cylinder.
Thanks

[Nick D.]

I think there are gaps recommended in the Haynes manual. I have that book, but not handy at the moment so if noone replies by tonight I will dig that up and get those numbers for you.

When I installed my 944 kit I called the place that sold it to me (BCM) and Bruce recommended different gaps than in the Haynes manual, saying his kit had different requirements than the OEM pistons. That being said, I would contact the manufacturer first before I used any generic settings.

[JimiDee]

There are a lot of specs besides ring gap (like torque values) that will make purchasing a shop manual for your bike worth the investment.

[ducxl]

Blake?...Is that you? OOps,wrong forum.I'm interested in ring gap though,as i soon set my new Pistals

[bruntr]

Don't know off the top of my head and my book is in the garage, but if motor is apart I would just buy new rings while your in there it's easier to do it now and they are not that expeinsive... last year while I had mine apart for a tranny swap I researched some zero gap piston rings for my 966.....

[Red Enough]

.003" per 1" of bore diameter.

[desmo11]

It is a scientific, proven fact that for motorcycles piston ring gap is at its optimum when it is set to a dimension matching the gap between the owner's front teeth.

Seeing as you are from ap northern Wisconsin dere, and thus in all probability genetically quite similar to da yoopers eh, you might want to order the large feeler gauge set.....

[brad black]

the ducati specs are 0.20 to 0.40mm from memory, whereas the old "4 thou per inch of bore" gets you about 0.375mm (15thou). if you had je or wiseco rings that's what they'd recommend, or even more.

off the piston in the bore is how you check it.

[ducxl]

Thanks for the imformative post.It applies to me......very,VERY soon.Like this week.My pistons are ready for minor re-machining.I've met with the machine shop twice.They're even going to fixture the first them call me over to approve

[996f1]

A reasonable starting measurement (no less) is .003" per-inch width; such as at least .012" for a 100 mm pistion. The end gap is measured with the ring installed in the cylinder, as-if sitting in the piston.