I had my mechanic call PR about ring gap. They told him to gap them at 18. I think he said Yamaha called for 12 to 16. Who ever he talked to at PR said most people just put them in with out gapping. My mechanic checked and they were only at 7.

 

I didn't inquire but since I was doing most of that myself, I checked them while I had everything apart and the gap was virtually non-existent. I went ahead and gapped all the rings at 18 based off of your unfortunate experience. [/emoticons/emotion-1.gif]

Plus, I do have a pretty good relationship with my mech and he said that was good thinking on my (your)part and 18 sounded dead on. I also slipped him a tip and asked him to give it all the once over before he re-assembled and he said no problem.

 

Any of you tech guys now what the stock ring gap is set at? My wrench set the gap for my OE 108 kit the same as stock. I don't want to ride it for awhile and then wind up like Troyus.

My bike just got finished, and I'm set to pick it up in the morning.

 

To tight is bad. A few thou over is good on an air cooled engine.

Standard practice is .004 per inch of bore diameter. .016 to .018 is safe.

For what its worth I set mine at .016 with a stock bore.

 

Your engine will crap out if the gap is too tight. One guy who races them says that he sets the top ring at 17 and the center at 37. Either way, they need to be set since they are not set from the vendor. PR told me that they should typically be set at 18.

We should have Rob get in his opinion. Also, if PR can chime in, this may save them both alot of trouble since the dealerships seem to have no clue about the gap setting.

quote:To tight is bad. A few thou over is good on an air cooled engine.
yeah I was amazed that mine lastet about 1k miles.

Guys, this could head off alot of grief.

 

Troyus, you are truly the patron saint of the ring-gap! Seriously though, I think we are all glad that you're spreading the word about potentially terrible effects from uninformed engine mods.

 

I just picked-up the bike! It seems to run pretty strong, there is some pinging at rpms above 3000; sound almost like the pushrods?

My mechanic said he set the ring gap at .013 - He said that seemed to be the right fit. I'm worried a bit because it's not between .016 - .018?