Availability of seals

[Downeaster]

Took the engine out of the '79 tonight. Not planning any major work, but it needs a thorough cleaning, the carbs had to come off for a rebuild anyway, and it just seemed easier to do with the engine out and on a stand.

There is a TON of gunk around the front sprocket. I haven't started cleaning things yet, and chances are it's from 30 years of over-oiling the chain. OTOH, it could be a dried out countershaft seal or a clutch pushrod seal (if there is one, I don't remember).

There's also a lot of slime on the bottom of the engine. I'm guessing the process of removing the sump plate to check the sump filter and replacing it (along with new gaskets and proper torque) will take care of most of that.

My question is this: If I start running into worn out seals, are these parts reasonably easy to find? If so, where do I look?

Also, while I'm asking stoopid questions, how's availability on new sprockets? The chain is wore slap out, and if I'm going to replace the chain, I may as well replace the sprockets. Stock ratio is fine.

 

[TampaSVT]

Took the engine out of the '79 tonight. Not planning any major work, but it needs a thorough cleaning, the carbs had to come off for a rebuild anyway, and it just seemed easier to do with the engine out and on a stand.

There is a TON of gunk around the front sprocket. I haven't started cleaning things yet, and chances are it's from 30 years of over-oiling the chain. OTOH, it could be a dried out countershaft seal or a clutch pushrod seal (if there is one, I don't remember).

There's also a lot of slime on the bottom of the engine. I'm guessing the process of removing the sump plate to check the sump filter and replacing it (along with new gaskets and proper torque) will take care of most of that.

My question is this: If I start running into worn out seals, are these parts reasonably easy to find? If so, where do I look?

Also, while I'm asking stoopid questions, how's availability on new sprockets? The chain is wore slap out, and if I'm going to replace the chain, I may as well replace the sprockets. Stock ratio is fine.

Down:
Complete engine seal kits on Ebay are roughly $30.00

Rich

 

[Downeaster]

Exellent! Thank you. I see Mike's has some of the common ones as well.

 

[XSLeo]

Chains and sprockets are on Ebay also. Mike's XS, 650central both sell the seals.
Both the clutch pushrod seal and the counter shaft seal, behind the sprocket, can be changed without tearing the engine apart, can be done on the bike.
The clutch pushrod seal being small is easy to mangle on your first try, but two or three when you get it. Better to have a spare handy than have to reorder. I like to use a phillips head screw driver that is a light slip fit through the seal. Put a large washer on the screwdriver, then slide the seal on. A bit of oil or grease on the screwdriver help prevent seal damage. Now put a very thin coat of Yamabond or simular on the outside of the seal. Now slide the screwdriver into the hole where the push rod goes.
This will guide the seal into the case straight, helps prevent damage to the seal. Now just a firm push should pop the seal right in place. The large washer prevents you pushing the seal to far in.
The seal behind the sprocket is often ok. Often the leak is from the bushing that slides through the seal. The bushing sets against the bearing on the shaft, comes out through the seal and the sprocket pushes the bushing tight against the bearing.
If your sprocket nut isn't properly torqued, often found barely finger tight, oil gets between the bearing and bushing, runs through the bushing and leaks out between the bushing and sprocket.
You can clean the area and change both seals on the bench. Not much harder on the bike.
If you are changing the seal often the bushing the pushrod moves through is worn. If you can wiggle the pushrod up and down and feel much movement then it's worn. Mike's has new bushings. On his site there is a how to on changing the bushing and seal.
Leo

 

[Downeaster]

Thanks, Leo. Excellent information. Good tip on the pushrod seal too, I'll make a note of that.

 

[retiredgentleman]

Actually that's not a complete oil seal kit in post #2. The oil seal kit I used from Mikesxs came with 10 oil seals.

 

[5twins]

Here's a link with some good seal replacement tips. They really help and work, especially the one about shaving the sharp edges off the case holes before installing the new seal .....

http://www.650motorcycles.com/XSseals.html

The clutch pushrod seal is a notorious leaker on these bikes. Usually, as Leo mentioned, a worn pushrod bushing has a lot to do with it. Best bet for a leak-free pushrod seal is to replace the bushing and switch to the long one piece pushrod, along with the new seal of course.

 

[drog]

Good info guys! Here is a little trick i have done on these bikes for years and cures the leaking pushrod problem.Buy 2 seals,cut off the 4 "teats" on the back side of them both.Make sure you clean,dry and chamfer the case hole.Now put a light coating of gasket sealer(your choice) on the outside edge of the seals and the inside edge of the engine case hole.You can now install the first seal,pushing it in as far as it will go,then the second seal on top of that one.There is enough room in there for 2 seals,the second one will not be quite flush,but that doesn't matter.I then spread a very light coat of sealer around the outside edge of the seal and case,let dry overnight.Hope this helps.

 

[5twins]

Hmmm, I like that 2 seal idea.

 

[Downeaster]

BINGO!

Started degreasing the engine today. (Note: NAPA/Gunk Foamy Degreaser is about as useless as tits on a trout...) and found both problems mentioned above: sprocket nut not even finger tight, and clutch pushrod flopping around like a wounded duck.

Also, sump screen torn in the usual spot, but peeking at the bottom end through that access, things look good. Nice and clean. No metallic debris on the drain plug magnets.

Oil filter on clutch side needs cleaning, but again nothing horrible.

Dropped both wheels in preparation for new tires and a new sprocket on the back. NONE of the sprocket bolts were more than lightly finger-tight. Good thing the keeper tabs were installed properly.

 

[Downeaster]

Looking at Mike's, he has a one piece replacement push rod for the clutch.

Is that a good upgrade, or should I just replace the short one that's there when I do the bushing and seal?

 

[xjwmx]

^People say the long rod makes it less prone to wear out the seal, but I don't know if that science has actually been done, or if it just sounds like it would work. If the rod you have is pitted in the area where it will contact the seal, it would be a good idea to replace it with one or the other.

I like having a good push rod seal - because if it drips oil from down there, it means I need to tighten the sprocket nut

 

[retiredgentleman]

I'd say there is no need to replace the short outer pushrod, unless its badly manged. If the area that slides in and out through the seal is in good condition, just keep using it. The new bushing and seal should get things working as normal.

I've used the long steel pushrod for the last few seasons and it works fine in its pushrod duties. However, because the engine cases are aluminum and the long rod is steel, a differential expansion occurs. The steel rod does not expand as much as the aluminum cases, with the result that the clutch lever freeplay grows larger as the engine heats up. I have to re-adjust the free play at the lever depending if the engine is cold or hot.

With the 2 short pushrods, the inner rod, which is about 2/3 of the total length, is aluminum. The aluminum pushrod will expand similar to the cases, and should keep the clutch free play more constant.

I've decided to go back to my stock configuration which is with the 2 short pusrods, with the ball bearing between them. I'll try that next year, with hopes that I don't have to keep re-adjusting the clutch free play.

Another thing you can do to help prevent wear on the bushing and seal, is to "dimple" the end of the pushrod and the wormscrew......see picture.

 

[retiredgentleman]

xjwmx;

I agree. I'm thinking the 2 short pushrods and the long single rod don't affect the bushing wear any differently. The bushing is going to wear, that's its job; so replace when required. The dimpling likely helps to centre the rod and minimize bushing wear.

 

[5twins]

I think the short outer rod does promote bushing wear. Even with a new bushing, it still flops side to side more than the long rod. RG, check the side to side "wiggle" on your long rod before you remove it then check it on the short rod. I think you'll find much more. That double seal idea would probably add more support to the rod and help curb the side play.

 

[xjwmx]

^Even at that, I'm not sure flopping from side to side would promote seal wear. If it flops to one side at a point in time there's more pressure on that side but correspondingly less on the opposite, so...

 

[retiredgentleman]

I think the short outer rod does promote bushing wear. Even with a new bushing, it still flops side to side more than the long rod. RG, check the side to side "wiggle" on your long rod before you remove it then check it on the short rod. I think you'll find much more. That double seal idea would probably add more support to the rod and help curb the side play.

Good point 5twins. I'll do a comparison of the "wiggle" with the long and short rods.

 

[xjwmx]

^will not prove anything. The only good test is one using good methodology to see if wear increases

 

[retiredgentleman]

I think the short outer rod does promote bushing wear. Even with a new bushing, it still flops side to side more than the long rod. RG, check the side to side "wiggle" on your long rod before you remove it then check it on the short rod. I think you'll find much more. That double seal idea would probably add more support to the rod and help curb the side play.

You are correct 5twins. There is a lot of "wiggle" with the short rod, because it has no support at its inner end. The long pushrod is supported at its inner end, so it does not "wiggle". There is a bushing of some type at the far end of the long pushrod. You can feel the bushing is about 1/2" long.

Well, I've been using the long pushrod for the last 4 seasons, so I may as well carry on using it next season.

 

[5twins]

I went through pretty much all the scenarios when I was trying to cure my leak. I started with just a new seal and a new short rod. It leaked as bad as the old one because the bushing was worn. Even a new good seal couldn't handle all that rod play. Next was the bushing replacement and another new seal. This reduced the side play but I still thought it had an awful lot. It did stop the leak but I figured just a bit of wear and increase in rod side to side play would have it leaking again. Last was switching to the long rod. It hardly moves side to side at all - problem solved.

As I said, it would be interesting to see if that double seal idea firms up the short rod. I agree, an alloy rod in there somewhere is better for maintaining consistent adjustment. I pulled the pushrod from an XS500 in my dealer's bone yard. It's a long type and alloy with steel end caps. Unfortunately, it's diameter is larger than the 650 and the length differs a bit as well. I'd love to mod it somehow and try it but I don't have a lathe.