heard of this?

smokie · Post by **smokie** » Wed Apr 22, 2009 2:37 pm

A week ago I replaced all the external seals under the clutch cover because the countershaft seal was seeping. There were no leaks for a week then today it decided to start leaking. It appears the cases are leaking at the split around the drive shaft seal. Has anyone else seen this or am I nuts? Ill try to post pics when I get a chance. This is on the 380, thanks.

tz375 · Post by **tz375** » Wed Apr 22, 2009 11:48 pm

I hope I misunderstood what you just said.

It sounded like you said there was a gap between the upper half of the crankcase and the lower half at the point where the cases are clamped around the seal.

If that is really what you have, then it's time to call Houston (as in "Houston, we have a problem")

There should be no gap there. The two case halves should be bolted tightly together. Are you missing some bolts or are they loose - or did some PO rebuild the motor and leave a bearing sitting high on top of a retaining dowel which is now trying to push its way out of the cases?

smokie · Post by **smokie** » Thu Apr 23, 2009 6:42 am

Well, Here it is. If you look closely to the right of the seal you can see the drip. The area around the seal itself is dry. Dont know the exact history of the motor. I bought it from the original owner who said all he ever did to it engine wise was re ring it. [img][img]http://i578.photobucket.com/albums/ss22 ... 0_1162.jpg[/img][/img] I believe we have a problem Houston. What I dont get is why it took so long to start leaking. This bike is a moody bitch!, but I love her just the same.

Post by **Suzsmokeyallan** » Thu Apr 23, 2009 7:49 am

Did you check the torque of the case bolts on each side of the sprocket seal where they come out the top of the engine case??? If it is leaking there next to the right side of the seal in the pic you could still fix it somewhat temporarily without splitting the cases.

tz375 · Post by **tz375** » Thu Apr 23, 2009 8:00 am

It could be an optical illusion, but it looks as if the black plug on the kickstarter shaft has a gap at the top as well.

That leaves you two options. One is to clean it all up and cover the outside with RTV and hope you can slow down the leak or you can fix it.

The problem with the coverup is that the real problem is still there and won't get better by ignoring it.

It may be a loose crankcase bolt, or a broken bolt. That one on the GT750 is the worst for corrosion and snaps more often than not.

What I would do it to take two self tapping screws and put them into the seal and pry it out. Then I'd carefully inspect the cases and that bearing. Can you slip a thin feeler gauge in above or below the bearing? can you slip a feeler gauge into the apparent gap between the case halves?

If the answer to either of those questions was "yes" I'd whip the motor out and pop the top off. If it all turns out to be tight as a Scotsman, you could get away with a new seal and a smear of RTV

It may just turn out to be that the seal has a gouge or scratch on the outer surface on that side.

smokie · Post by **smokie** » Thu Apr 23, 2009 8:15 am

Ill check the torque of those bolts first. Hope the cases dont have to be split! (but im counting on it). Or I could deal with it for now. No worse than an old Harley or Triumph right?

Post by **Suzsmokeyallan** » Thu Apr 23, 2009 11:50 am

Lets know the status of those bolts torque, if you wish you can use the RTV, but i'd use some JB weld or plastic steel running a bead along the seam after a proper cleaning.
This can easily be cleaned off at a later date if you have to split the cases, and from my experience holds better for such issues.

smokie · Post by **smokie** » Thu Apr 23, 2009 12:51 pm

Well, I managed to snap 1 bolt. According to my info the 6mm bolts should be around 9.5 ft lbs and 8mm ones 15 ft lbs. I also read the S marked bolts should be around 15 ft lbs so thats what I torqued them to. This may have been too much. It seemed like the bolt was turning too easy from the start also (like it was already broken) but I cant be sure. My Crapsman torque wrench may also be at fault but I dont know. Is it possible to extract these? Theres not much to work with (bolts are 6mm).

tz375 · Post by **tz375** » Thu Apr 23, 2009 1:22 pm

They are not hard to remove but usually require the cases to be split to get to the broken part.

Timing isn't good with riding season upon us, so you might consider riding it through teh summer and stripping it in the fall. The "right" answer is to do it right, so I would order gaskets and seals etc and then I'd do a compression test and leak down test to see if it really needs more extensive work.

No point in doing all that work and then have a bad crank or pistons worn our etc, so measure it all up and take a deep breath before you commit to a tear down. I hate tearing into things only to discover that a whole lot more needs to be done and I run out of cash and enthusiasm, so the thing lies in a pile in the shed.

So I like to get a good idea if anything else is likely to be wrong so I'm financially and mentally ready to deal with it. If not I just ride it and keep applying RTV until something major goes wrong.

smokie · Post by **smokie** » Thu Apr 23, 2009 1:59 pm

It appears I may have over torqued them. Anyway, I dropped the torque down to 10 ft lbs and tried the others. They were loose. The 380 may get put up this summer until the finances shape up. You guys may cringe to hear this but im starting to get hooked on the early xs 650s. These are really cool bikes if you dont mind the vibes. I was thinking about doing a hard tailed bobber.

smokie · Post by **smokie** » Thu Apr 23, 2009 2:00 pm

Or this

tz375 · Post by **tz375** » Thu Apr 23, 2009 3:58 pm

Popular bikes with the AHRMA crowd and lots of parts available from Mikes XS at the right prices too.

Suzukidave · Post by **Suzukidave** » Thu Apr 23, 2009 5:05 pm

This one in road racer trim i saw at the vintage races in Daytona was super cool .

H2RICK · Post by **H2RICK** » Fri May 01, 2009 9:01 pm

Just a thought but.....MAYBE the original problem might have been the spacer collar/shaft seal interface being badly worn.....either on the collar OD or the lip(s) of the seal.....or both.
Another problem area can be that skinny little oring inboard of the spacer collar.
What are you running for gear lube ???.....and please don't say a synthetic of any kind.....

My .02 worth...

smokie · Post by **smokie** » Sat May 02, 2009 4:50 am

Ill check that Rick, im running castrol 20w50. I just looked and everything appears fine around the seal area-I assume this is not a common problem. It appears the old sealant is deteriorated. Ill post pics when I get home from work. Cases are split.