XJ650 outer throttle shaft seals

Hi all,

When I do a vacuum leak test with carb cleaner I seem to only have a vacuum leak in the outer throttle shaft seals on #1 and #4. I can spray the stuff all over the place but only get any sort of reaction when sprayed on the outer throttle shaft seals.

I am thinking about taking the easy way out (for now) and buying some time until I need to re-do the entire rack by only replacing the outer throttle shaft seals. Pretty cheap and easy to do and I think would be worth it if if I could delay the complete carb rebuild for a couple years.

Other than detecting a leak when I test for it the bike runs just fine.

Has anyone only done the outer seals on #1 and #4?

Is there a reason these would deteriorate faster than the inner seals?

Thanks everybody! Hope you're enjoying the long weekend if you're here in the states!

 

yes you can do that.
exposed to sun and elements more that other seals.

 

OK, thanks, I'll give it a try. I'm curious to find out if it makes a noticeable difference either in how it runs or the carb tuning.

 

if seals are leaking those cylinders 1 and 4 should/may be running lean.

 

Just to follow up - I have replaced the outboard throttle shaft seals and it definitely fixed the problem - no more engine acceleration when sprayed with carb cleaner while running.

I can't tell if there's any real difference in how it runs, but I haven't put the carbtune on it yet either.

Once valve lash is within spec I will throw the carbtune at it.