Does anyone know the size of the O ring that fits onto the end of the silencer that fits into the main exhaust?

I cant find the sizes anywhere - once I know what they are I can get a viton O ring of the correct size.

Think mine still has the OE one fitted as it has gone hard and there is oil dribbling out of the joint.

Many thanks.

This can probably be "read" from the part number.

See the link below to see what I think is the correct part number - ie 93210-27250.

O-RING (438) for DT400 1976 USA - order at CMSNL

According to a Yamaha parts manual that I'm looking at, 'O' ring dimensions are shown in part numbers as "Section Area - Inside Diameter". I think that section area is the diameter of the 'o' ring rubber etc. Therefore my reading of the part number is the thickness of the 'o' ring is 2.7mm and the inner diameter is 25mm. HOWEVER, I'd like another member to confirm this!!

  

They are on eBay….

Item number: 175081670231

Hmmm,
From memory (which ain’t what it used to be), mine was 28 (inner diameter) x 3.5 Viton.
They are cheap on eBay (so long as you stick to generic, viton o-rings).
Experiment with a few and see what fits best….

Believe it or not, but even this topic has been discussed here before.

One member reported the o-ring dimensions as 3.12mm (cross-section) by 27.4mm (diameter) and that he found the size where he worked.

Another was using an o-ring from a Harbor freight o-ring kit.

And someone else said that the high temp o-ring off of an old burned out 9007 headlight bulb from their Dodge Caravan worked perfectly.

Thanks everyone - I'll have a dig around E-Bay / the web to see what I can find nearest to 3.1 x section x 27.4 I/D in Viton.

I dont know anyone with a an old burned out Dodge Caravan so guess I'll just have to get what I can from the web :-)

"Genuine" O rings are way too costly.

Thnanks again.

Dodge Caravan headlight bulb burned out, not the whole van. 

I find it humorously ironic to joke about the old headlight bulb o-ring suggestion (FREE) that I passed on and then complain about the price of the original o-ring in the same post. 

Many cars use the 9007 headlight bulb...  and I'm sure most people just toss them when the bulb burns out...  I tend to be one of the ones that remove and save the o-ring off an old headlight bulb before tossing it.  Yes, I have a LOT of "junk"... but it's quite satisfying to me to make repairs and even build things without having to go to the store or online to buy new.  (Or pay stupid prices for a NOS part. )

 

Junk… something you throw away just before you need it…
Sneezles61

MarkT I’m glad I’m not the only one to repurpose stuff got a lot of mini chargers (phone etc) power cords, brackets now for some orings 

Mark T - seems like you may have taken my comments out of context, the one about the Dodge was supposed to be humerous, and in respect of an OE O ring, they are too costly when you can buy a generic O ring for peanuts that will do the job.

Apologies if I have upset you with my comments, it was never the intention.

Cheers.