Throttle Shaft Seal, Oring Option Questions

1982 xj650 Maxim was running well (some weird vibration issue, but I don't think it has anything to do with the carbs), but would have a hanging idle after about 15-20 minutes of riding. During first bit of riding, idled nicely, accelerated well and returned to idle as it should.

Checked for air leaks in boots, and found none. Research shows that throttle shaft seals are very likely culprits.

There's also been posts that #11 o-rings can be used to replace these throttle shaft seals. I have some 11mm x 7mm o-rings, and they seem to be a pretty good match when matching from above, but matching from the side, two stacked are significantly higher than the original seal. When I stack them lubed, they are binding up the butterflies. And putting on those e-clips is a nightmare.

Can anyone who's used the o-ring substitution give some insight? I see some 11mm OD by 8mm ID orings available. Would these work better?

Thanks,
John

 

#11 is not an 11mm o-ring (close, but not quite close enough).
The recommended o-ring size is of a U.S. standard. Any decent hardware store should have them (but maybe not in Canada). N-Buna is the prefered material.
o-ring-size-chart-as568.htm

Chacal has the correct throttle shaft seals in stock if you can't source #11 o-rings.

 

Thanks so much, k-moe! I couldn't find #11's, but 5/16 x 7/16 are definitely available. Doing the math, it comes in at just under 8mm by just over 11mm, so I can see how those would fit better than what I have.

 

Doesn't make sense to me why you wouldn't use metric? I bought my kit from Brian at BDDesigns and it came with every oring needed for my turbo's sealed carbs. Piece of cake rebuilding them and knowing I used the CORRECT sizes, I didn't "wonder" how it was going to run! It's now been running approx 6 yrs since a full restoration and doesn't miss a beat.

jeff

 

that is the fractional size of #11

the size that works in mm is 7.62 id by 11.2 od by .177 wide .....or #11

 

The original seals are a custom size, which is why substituting a pair of metric o-rings for each seal won't work.

 

So, for any Canadians out there, carquest keeps them in an O-ring box, on the post labeled "r-04".

Fit beautifully, no binding and e-clips snap right back in. Thanks a ton, everyone.

 

What size of seals are used in the T joints between the carburettors? Do the above throttle shaft size seals fit the BS 36 carburettors? Are the seals the same size for all the XJ range?

 

i think those are "D" shaped, i mashed a "O" ring in but it cut itself going in, not good but it worked.

no idea

they worked on my Hatchi 750 carbs so they should work on 650's, don't know about others

 

They are round, not D. The ones that are REMOVED look like D because they've been in so long they are deformed. ("D"-formed?...lol)

 

I wonder if I can get that "0" ring kit from Carquest in Santa Fe