Throttle Shaft Seals

[gr82bwild]

I've got a 79 XS1100F with hardened rubber seals on the carburetor butterfly shafts. This causes the typical "lean running" performance (won't idle down, overspinning during an upshift, poor "low throttle" carburetion). I ordered new seals from Mike's XS (P/N 48-5021) and installed them. Unfortunately, I confirmed my air leaks remain using starting ether; sprayed it around the outside of the throttle linkages with the engine running and got definite 'increased rpm" reactions. Removed and disassembled the carbs again and confirmed the new seals are a "loose fit" to the throttle shafts. In search alternate sources for these seals, it appears that the standard size (8mm ID x 11.5mm OD) is all that is available. I'm suspecting I need something like a 7.5mm ID to get a good seal. One idea I've noticed is "packing" these seals with some grease. Anyone got any experience with this, and, whether it will last very long?

[newc4]

A judicious application of carb cleaner will cause the seals to swell. If they swell too much a dab of brake fluid will bring them down.

Darrell

[gr82bwild]

Hmmm; hadn't thought of that approach. Is this the normal thing to do with these seals; even new ones?

[mro]

I'd get the OEM ones, cost around 5 bucks ea tho

80's (BS34 III) are only about half that.

I've not checked if there be any difference in the shaft or carb body dia between the II's and III's but they are different part #'s so you should have to get the more expensive ones.


mro

[trbig]

So what IS the right part number? Am I looking at the right thing on the Fiche? 256-14997-00-00? If so, right here at Boats.net shows them for $2.75, but I have no clue what the shipping is from there. Doesn't seem like it should be much for 8 tiny O-rings..

Tod

[RODS454]

Seals

That fisch only shows seal on one side. Is that shaft not removeable? Does it not need seal on both sides of carb body? Also, the only part of the number that is different is the first 3 digits. Could they be the same?
RODS454

[gr82bwild]

Stopped by my local Yamaha shop this past Monday and confirmed that the OEM seals are still available (P/N 2A2-14997-00-00) at a whopping $8.88 each. I ordered one, which is expected to arrive this coming Friday. I'll verify the fit before investing in any more. True, the fiche at the Yamaha shop does show only one seal on the inboard side of the #3 carb (#37), but, I strongly suspect this is just a drawing convenience; not trying to indicate that there is only one seal per carb. Thanks for the reference to the seals at boats.net. I may try those much cheaper parts before taking the plunge with more of the OEM parts from the Yamaha shop.

[petejw]

i had the same problem after buying
genuine yammy seals, they were .5mm to small
on the outer diameter, they wont fit and arent the right
ones for our carbs.

i got my seals a little while ago from mikes xs
ive got a pack in front of me with the number
48-5021 they fit perfectly and from memory
were quite cheap.

[bgrubb7]

A judicious application of carb cleaner will cause the seals to swell. If they swell too much a dab of brake fluid will bring them down.

Darrell

I do this all the time with various rubber parts, but use PB Blaster instead. Swells the right up, but you have to check them incrementally while soaking, otherwise they can swell too far. Seals will shrink back down over time, but it does take a while. At least it would tell you if that fixes your problem initially and whether or not its worth spending your money on the $9 Yamaha seals...

[gr82bwild]

Got the one OEM seal I ordered from the local Yamaha dealer today (P/N 2A2-14997-00-00) and it fits much better than the seals I got from Mike's XS (P/N 48-5021). I have so much confidence in the OEM part number seal that I decided to order eight more from boats.net this evening (much better price at $5.55 each). Hopefully in another week I'll have the beast reassembled and purring pretty. In the meantime I'm working new coils, wires & plug caps along with brake pads. Thanks for all the responses and suggestions.....

[petejw]

mines an 81 model, seems that the early and later model
carbys are different .
glad you got yours sorted.