Piston rings, anyone?

[Pescatore]

I have been repairing a head and base gasket leak on a 1991 V65GT.  Now that the pistons are out I decided to replace the rings.
I discovered that I have a 2nd series pistons/cylinders, which uses a 2mm middle compression ring instead of 1.5mm (Thank you Guzziology for resolving my confusion, engine# PG19395).
The other two rings are the same as all older and newer V65s.I checked the usual sources and the new series rings (3106 0616) are either unobtainium or wicked expensive.
The middle ring is not available by itself (2706 0860).

I bought a new sets of the 1st series and didn't realize my mistake until assembly time.
What is the collective wisdom in this case?  Reuse the old ring with the new ones?  Put back the old ones?  They don't seem worn, but I don't know for sure.

I also would like to decipher the information in the V65 Florida parts catalog.
The scan quality is poor and I want to confirm what it says in the A11 and A12 pages.
I am mostly interested in making sure which symbols on A12 refer to the 2nd series piston.


Grazie mille

[Chuck in Indiana]

Have you looked here?
http://www.deves.com/

[Pescatore]

Thanks, Chuck.  The Lario kit might have what I need.  I hope they sell individuals.
Does SK mean second compression ring?

[StuCorpe]

Could you possibly change the pistons so they take the type of rings you have?  I have no idea what the cost differences might be or even if it could be done.

[Chuck in Indiana]

Thanks, Chuck.  The Lario kit might have what I need.  I hope they sell individuals.
Does SK mean second compression ring?

Yeah, they sell to individuals. You'll have to give em a call for anything their robot can't handle. 

[Pescatore]

Could you possibly change the pistons.....

That's thinking out of the box.
It would be more expensive and difficult to match to the cylinder.
I also suspect I would need a 1st series head, which has a shifted spark plug hole. 

Yeah, they sell to individuals. You'll have to give em a call for anything their robot can't handle. 

[Alfetta]

why not open up your groove ?   its only 20 thou. ??

[Pescatore]

Thanks Alfetta, but I have the wider groove. I need a thicker ring.

[Mike Tashjian]

Put the old ring or rings in the cylinder and check the end gap with feeler gauges to see how worn they are. On cast cylinders the bottom third usually shows the least wear but you said you have Nikasil so probably anywhere would be fine to measure. Just make sure the ring is in the bore square when measuring. Using a piston to push it in is the usual way.  I know your piston coating is an issue but maybe since the ring portion shows no coating you can still get a ring in an inch or so.  Not sure what your bikes gaps should be but, you should check even new rings to be sure they are in spec.  Consulting a service manual for that spec is one way. 

[Pescatore]

Thanks, Mike.  I  read about that ring gap method on   Guzziology.  And I found specs in the workshop manual.
Here is my new dilemma.
The V65 workshop manual I've been using is for the 1st series piston.  I am not sure if any of the specs also apply to the 2nd series piston.
I need to dig through Guzziology for more details.

The first confirmation I found of these newer pistons is the V65 Florida parts list I posted.
I looked for the V65 Florida workshop manual and found only a partial copy.  It seems to be an addendum to the manual I already use and
it only covers the V35 piston.I will look through all the other V65 variants hoping to find one that uses the newer piston and has related specs.
Back to googling.

[Dukedesmo]

When I was looking for new rings for my Ducati Monster, I contacted CP-Carillo and they have a huge range of rings in different sizes & materials - sorted me out with a set and at a fraction of Ducati prices.

[pressureangle]

When I was looking for new rings for my Ducati Monster, I contacted CP-Carillo and they have a huge range of rings in different sizes & materials - sorted me out with a set and at a fraction of Ducati prices.

Total Seal made custom rings for my '85 LM1000. They have a huge catalog and are very accommodating to individual customers. Another possibility.

[Pescatore]

Thanks for the replies, Folks.  I sent inquiries with all three (Deves, Carrillo, Total Seal).
Someone warned me about measuring the pistons first, which I don't have at the moment (long story https://wildguzzi.com/forum/index.php?topic=117942.msg1864162#msg1864162)
Hopefully in a couple days.

Question: Is the ring play in the piston slot for the 2nd series piston the same as the 1st series piston?
I am referring to the picture below, 30-62 microns.  Those specs are for the 1st series piston.




Thanks!

[Chuck in Indiana]

*I don't know* but I would think so..
(bump to the top)

[RinkRat II]

   Standard clearances  run .001-.003"/ .032-.062mm on compression rings unless they are a purpose  built racing arraignment. I would also check the depth of the piston groove versus the width of the ring. My $.02

[PeteS]

Total Seal made custom rings for my '85 LM1000. They have a huge catalog and are very accommodating to individual customers. Another possibility.

I have Total Seal rings in my 850 LM plus Norton and BMW airhead. If they don’t have them in the catalog they will make them. Make sure you specify, iron liners or nikasil. Leakdown tests typically read 99% or better.

Pete