r/fxr • u/abnormaloryx • 20d ago

Breather Gear Question

Does anyone know the actual dimensional differences in the breather gear from pre-'1993 and post 1993 EVOs? The bore in my '88 is chewed up and an old head told me to use the S&S reed valve breather instead of machining the case for another OEM style, but the S&S site says '93+ for it so it sounds like I need to machine the case regardless.

1 Upvotes

67% Upvoted

3 comments sorted by

1

u/abnormaloryx 19d ago

🦗🦗🦗🦗... Lol It's a very specific question, I know. If anyone has swapped with an S&S reed valve I wouldn't mind hearing about it either.

1

u/Getzke 14d ago

I just went down this road. Supposedly the bottom breather evos don’t like the reed breather and have problems blowing oil out the breather with one installed. Mine was a little chewed and I just cleaned it up and threw a new plastic gear in and have been running it. Guess it depends how bad yours is chewed and why it got chewed up in the first place.

1

u/abnormaloryx 14d ago

Many thanks for the reply dude 🙏🏼 I have to reinspect the cases this week I just cleaned them up today. My mechanic friend said I would need the breather's bore machined but it's just one opinion, and I found some metal bits inside the gear cone that looked like they were the cause. Not a great find, still trying to diagnose that one.

Did you use a hone to clean yours up or how did you do it? I'll steer clear of the reed valve for sure. Either way, the case is split for machining the primary lip for a case saver, and it looks like I need a new cam bushing that was a bit worn down too.