pitted fork tubes

[Lamric]

..As for the part numbers, does Yamaha do the same thing as Suzuki making part numbers different even though the two parts are the same if the machines they are used for are different?

Luck for us, No, they don't do that.

Generally, Yamaha use the same part number irrespective of what bike/model the part is fitted to. The first three digits of a part number will give you the model code for the bike 7 model that the part was first used on.

All the Specials (inc Midnight's) use the same fork tube 3H3-23110-00-00

[crazy steve]

Are you suggesting that any inner tubes from Mikes 37 mm tube list are direct swap? Is it that easy with inner tube swapping?

No, it's not. It's been noted here that not even the Special and Standard inner tubes will swap due to slight machining differences between the two, so the chances of finding a set off that list that would fit are extremely poor.

So you have three basic choices:

Find a good used set of Special forks.

Get new tubes from Frank.

Swap to different forks.

The easiest swap would be to a set of 'standard' forks, but you'll have to also get the triple trees, axle, fender, and the brake calipers to make it work.

'78E original owner

[bikerphil]

Just to add, if your tubes are a bit nicked up or pitted, you can use the Leak Proof brand fork seals. They were originally designed for motocross use but now are made for street applications, and they do a great job sealing on slightly damaged tubes. I've used them before and they worked great for me. JAT

http://www.denniskirk.com/jsp/produc...Id=&mmyId=7771

[jmnjrpa]

Sorry about the missconception

I sometimes forget that not everyone has easy access to machining. As stated the inner tubes configuration is different among models and Manufacturers. I intended to say that most of the list has the proper size and length that can be converted (by machining/welding) to work. A direct swap without additional work or parts requires that the tubes are from a special as all specials have the same inners.

Don't know why anyone would think aftermarket seals are inferior to OEM? They may even be from the same factory. In my research fully 75% of replacement parts actually come from the OEM. I think there may be a mistaken idea that Yamaha made all of the parts they installed. I could be wrong, it did happen once before........

[dontlikeoc]

Thank you for your comments. It is very helpful to know what other non-standard remedies may be out there. For now, I will see how long the new seals will hold. Non-leak seal sounds worth a try.

I know from experience, that applying epoxy or something to the surface of the inner tubes to smoothen doesnt realy help.

One local German-trained mechanic says that, in old days, they used to fine-sand the pitted tubes to smoothen before putting on the new seals. Did anybody ever actually try that technique on an XS?

[bikerphil]

The problem with sanding is the slippery chrome coating is removed from the tube and might result in a stiction problem. If they start leaking again, I'd go with the Leak Proof seals. They were designed for this type of problem. You can install them easily, they just press in with your fingers.

[rpgoerlich]

I used a set of XJ1100 upper tubes for my special. They were a bit longer, had different valving and the air assist was through the side. I welded up the air holes, gutted the adjustable valving, used my top plugs w/air assist valve along with the springs from the XJ.