Best exhaust flange/gasket for 85 R...running FMF Fatty...

**350Kris** · 09-01-2009, 12:35 PM

I have a full FMF (Fatty & Powercore). I have a pile of goop sitting my engine right below my exhaust flange. Beside ordering a new gasket (stock I assume) is there any way to get a better seal? Does the stock exhaust flange, gasket and ring work best the the FMF Fatty? Any info. would help...thanks!

**Billy Golightly** · 09-01-2009, 01:47 PM

Almost all of the billet aluminum o-ring style flanges on the market work better than the stock setup. the ESR is one of the most popular ones.

**350Kris** · 09-01-2009, 02:11 PM

Thanks Billy......I think I'll go with an ESR. The replacement o-rings are only 95 cents, too. Very helpful folks.

**honda250sx** · 09-02-2009, 04:09 PM

Personally I dont care for the aluminum ones they wear out way to fast. If i was to purchase one I'd go with a Duncan Racing Stainless steel one. They dont wear near as much as an aluminum one will.

**350Kris** · 09-02-2009, 04:31 PM

Just out of curiousity...how do they wear out?...what causes that? Seems like that flange would not be sujected to much abuse.

**honda250sx** · 09-02-2009, 05:18 PM

Vibration...

**350Kris** · 09-02-2009, 05:25 PM

Just talked to a guy at Duncan...he made some valid points about pressure and so forth at the flange.

I'm on the road right now, so I can't check. Could someone tell me what the gasket I highlighted red in the attached picture is made of? It's the engine to ex. flange gasket. I think mine was in good shape. I just want to make sure it does not need replacing. I'm ordering parts this week so can get my R back together next week..... Thanks!

**Billy Golightly** · 09-03-2009, 01:13 PM

Their sort of a pressed fiber with a reflective aluminum sheeting over them, or some other extremely thin metalic material.

**lndy650** · 09-03-2009, 01:25 PM

that would be steel core with graphite i believe

**Dammit!** · 09-03-2009, 06:54 PM

I've been running a billet one for about 4 years now. No sign of wear or leaking yet. Haven't even had to replace the o-rings yet actually.

**350Kris** · 09-03-2009, 06:59 PM

Hmmm...good info.

!

Thanks for the heads up on the gasket fellas. I'm pretty sure mine is good to go. Just wanted to make sure it wasn't 100% fiber.

I'll let you guys know which one I go with now...

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Best exhaust flange/gasket for 85 R...running FMF Fatty...

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