took apart carb rail and completely disassembled the carbs where do i get the

[brentjgordon]

new butterfly shaft rubber seals that go on those shafts? i bought the rpm kit but it does not include these seals (they dont look like ordinary o rings) will ordinary o rings work if the size od and id jive with the shaft and body?  thx alot!!!

[FJmonkey]

Wow, I tried checking a few of the on line parts fiche and the butterflies or associated bits are not shown as a replaceable part. I would recommend that you email or call Randy at RPM www.rpmracingca.com, he lives and breathes FJs and related fun stuff. Its likely he will have them in stock, might even give a few for free if you buy one of his new shirts.  He is a Yamaha dealer and also develops and sells custom stuff for FJs.  He the go-too guy for many club members including myself.

[brentjgordon]

i got to checking mcmaster-carr and i just need to get the dimensions correct and i should be ok...i do appreciate the input though and i have used rpm quite a bit...good source! thx!!!

[Tiger]

(they don't look like ordinary o rings) will ordinary o rings work if the size od and id jive with the shaft and body?  thx alot!!!

I do not believe that regular 'O' rings will work, as the seals have to 'roll' with the shaft when actuated. I would contact Randy at RPM as FJM suggested.

John.

[paulfj03]

I could be wrong, but, ... It sounds like you are referring to the carbs for the Yamaha  XJ (seca/Maxim) ..... Not an FJ.

The shaft seals are a 'must do' when cleaning and rebuilding the xj carbs. I have yet to see on this forum a recommendation to change those seals for the FJ's Mukini rack of carbs.  Does the FJ even have those seals? . The carb gurus would know.  

My Yamaha 83 xj750 Midnight Maxim has the Hitachi carbs and it is highly recommended that the butterfly shaft seals be changed during a cleaning as they usually are the cause of an air leak.


HTH.

Paul

[movenon]

Kinda wondering the same thing.. I don't remember any shafts in mine, but I am old and forgetful.. So please forgive me.

[Shaun]

Yes there is a seal on the butterfly shaft, no it is not an O-Ring it is a open sided seal like a "BAL' ( no spring in it though) seal cross section looks like a squared off U (Monkey may know these or Mechanical design types). To see it you need to remove the butterfly, take the retainer of the end of the shaft and slide the shaft out. The seal in question sits in a counterbore in the carb body behind a reddish colored plastic washer. The seal does not show on the parts sheets on line so I don't think it is real common knowledge or a particular wear/replacement item. I came to know of this seal when I recently rebuilt my carbs, shaft was sticky and would not move freely so remove butterfly and and shaft for inspection find one seal under the washer and when the shaft comes out you lose the other seal to some dark void in the garage. In reality the seal actually makes it into the container of parts cleaner and hides there for a day or two. When said seal is found you notice that the seal has gone really soft and swollen in size by about half and does not seal on the shaft or fit back in the counterbore ever again! Answer Email Randy and he luckily has a parts carb body with a willing seal to save the day. Could you use an O-Ring, in an emergency sure, Buna-N is the one to use in something like a 70 durometer (most common) should do. Never Silicon as it is too soft and abrasive, Silicon O-Rings should never be used in a rotational situation even when lubricated not to mention lube alters the properties of Silicon O-Rings. Using an O-Ring on the shaft in the counterbore would not work properly for a long time as it would not be under enough compression to seal properly ( see plastic washer) and probably cause a sizeable vacuum leak.

My three cents worth and experience with this very thing.

Shaun

[brentjgordon]

three cents is worth alot here at fjowners....so after looking into the old parts i  found this gentleman correct and recovered the "squared off" orings and orientated them correctly on the butterfly shaft and no longer need "new" parts (at least those new parts), i would like to thank everybody for having patience with the new guy....i have found all the resources here on fjowners invaluable!!!!!thx again, and im sure you will hear much more nonsense from me before im through....