EC250 exhaust O rings?

[BIG TOOL]

Hi Guys, I was looking at the parts crossover list to see what O rings to get for my exhaust spigot, but all it said was " late model CR250 " Well I couldn't decide if that meant the '92-'01 or the '02-07 Cr250 or will either style work? I'd appreciate it if anyone could set me straight about this...
Thanks!

 

[GMP]

'92 - '01, or buy in bulk from an o-ring supplier. 44mm x 3mm Buna N. Viton is better but more $$.

 

[Brian VT]

I was at the corner store here in the woods of VT and, much to my suprise, they have an assortment box of Buna N for $.50 ea.
The sizes weren't listed though. Just a single # like 20 or 30. I googled but didn't find any reference like that. Any clue ?
Maybe I need to look at the box better or just grab a couple and try 'em.

 

[GMP]

Those are standard sizes, not metric.

www.mcmaster.com

www.callapg.com

 

[eff]

I ordered a bag at work. I can send you some Brian.

 

[GAKLX]

so what do you order ??

 

[eff]

I ordered 44 X 3 Buna N.

 

[slocalspode]

Was the, (44mm) X 3mm, an I.D. Internal Diameter or O.D. Outside diameter?
I could take my pipe off and measure one, but, I am feeling lazy today.

McMaster, Metric Viton O-Ring 3 mm Width, 38 mm ID/ 44 mm O.D. 9263K316
Metric Viton O-Ring 3 mm Width, 44 mm ID/ 50 mm O.D. 9263K739
Thanks, Jeff

 

[GMP]

44mm ID, 3mm width

 

[slocalspode]

Thanks, Jeff

 

[wence]

Just checking,
Is this still correct with the 07 300 also.
Do the viton last longer than the normal?, as I go through a set in a ride normally. I have to admit that the pipe was bent when I purchased the bike and I probably have not helped.
Cheers Mark

 

[GMP]

Mark,

Yes, the viton last longer as they are more heat resistant. Like you I'd go through a set of Buna N (black rubber, lower grade) in one ride because my pipe might not be perfect and side load the spigot a little more when mounted. When removed the Buna N are flatter on one side. This was becomming a PIA as I have to remove the Hyde, so I bought a bag of viton 44mm x 3mm. So far a few rides and no leaks so all is good. I have also tried going with a slightly oversize o-ring for a tighter seal but I could not get the pipe on (even my brand new spare pipe) without damaging them.

FYI, the OEM silicone are very heat resistant but have poor abrasion ressitance, and get worn away by pipe vibration.

 

[wence]

Glenn,
So the buna are better but viton is the best?
The I.D is 44mm on mine and thickness of ring is 3mm?I assume this is correct as I cannot see GG changing this between 250-300 etc.
Thanks Mark

 

[GMP]

Mark,
Buna N is cheapest, most common oring material in auto/MC applications. Good petroleum, abrasion resistance, poor to moderate high temp resistance. Silicone is very good for all but abrasion resistance. Viton is best for this exhaust application, abrasion better than silicone, temp resistance not as good as silicone but way better than Buna N and adequate.

Size is 44mm x 3mm all years, 200/250/300.

 

[wence]

Cheers Glenn,
Purchased some Viton o-rings today so we'll see how they go.
Thanks for your help mate,
Mark

 

[gasgasandrew]

Hi i use 05 KTM 200 exc orings as there high temp silicone and they last for months of riding tried viton orings and these ktm green orings leave them for dead ,There pricey at around $10.00 but i have tried to get them from a bearing trader but them only have brown viton and black standard and have never seen the ktm type before thanks andrew

 

[wence]

Thanks Andrew,
I'll be getting in touch with you if these don't work.
Cheers Mark

 

[GMP]

The green is probably not silicone. i have some green orings in my Ducati and they are EPDM.