Butterfly shaft seals..

Where is a good place to get these seals if Yamaha does not list them ? Are they nothing more than O-rings ? If yes than Buna-N O-rings should suffice. Mine appear to be leaking because they dirty up pretty quick after I clean off the outsides.

Marty

 

A source just appeared for them. Hit the search function, it was posted about two months ago. Something to the tune of $5 USD a pop.

 

Just a note: If you are going to replace the seals, look at the back of the butterfly plate screws. When I had my carbs off I noticed that the screws were staked over. If you try to remove these screws without a little bit of dremal work you could break off the screw heads or destroy the threads in the shaft.
Just a warning and something to look for.
James

 

Thanks for the heads up on the little screws. I for sure would not have thought of that.

The Muppets are cool.......Wakawakawaka indeed !

Marty

 

Stake them over again after you put them back in.

Not good if they come loose - pistons don't chew them very well.

 

Better idea, install new ones then stake. Old ground off screws will be getting pretty short.

 

This SHOULD be over in the PARTS FOR SALE section, but no one would notice it over there, and since it's appropriate for this thread, I hope no one minds me hawking these parts here. And besides, my prices are better than anywhere else! So........

I've got the correct throttle shaft Rubber Seals, with the correct outer diameter and inner diameter, that fits the Hitachi HSC32 and HSC33 carbs correctly, $3.50 each or $26 for a set of eight (plus shipping). Unlike the McMaster Carr QR011 or QR012, these seals are just like goldilock's porridge: not too big, not too small, but just right and oh-so-tight......

Sorry, couldn't resist that.

They do NOT have to be glued into the shaft bore like the QR011's do (the QR011's have too small an OD to fit into the bore tightly, and although they grip the shaft properly, their lack of proper OD results in them rotating with the shaft, which is not a good idea).

The QR012's are too big an ID, and don't hug the shaft tightly enough for a proper seal. The shaft-to-seal interface is where it's going to leak vacuum, and you sure don't want to go to all that trouble to replace the seals with ones that have a good chance of leaking after a few months or a year down the road.

I also have replacement throttle shaft rubber seal Nylon Washers....the white, thin nylon washers that go outboard of the seals. These washers are only half as thick as the originals (1mm originals vs. approx. .55mm thick for these replacements) and I've used them successfully to "shim" the stock washers and tighten up the shaft end play. The original washers wear a bit over time, and the addition of these 1/2-thick washers makes for a nice snug fit of the throttle shaft assembly. Depending on how worn your original washers are, you may or may not need to use these on all 4 carbs. $ 1.50 each or $10/set of 8. NOTE: originally, there were only 7 of these washers used, as the #3 carb on the left or "inside-center" side of the shaft used a very thick plastic spacer/bushing instead of a thin flat washer.

Oh yeah, and the throttle shaft-end retaining "E-clip", $1.00 each, used on the outboard ends of the end carbs only........use 2 per bike.

I'm working on getting the butterfly screws made in stainless.