The Hodaka Club Forum

Well it's good to know I'm not the only one who has lost his damn mind working on these bikes . But yes I have removed the stator and sprayed around that seal with nothing doing. I should had listed that in things I've checked. But thanks for the advice. If my garage wasn't such a disaster right now I'd let it go for a few days to regain my composure but I want my damn garage back.

Al, what did the leak end up being?

Sounds like it is time to strip all the parts you can off the engine. Since the magneto side has already been done, that leaves the clutch side. Pull the clutch and primary gears, so you can search that side closely for leaks. There are no options, gotta find the leak.
Ed

Well when I get home tonight I'll do just that. Thanks for the motivization guys!

Where I found the leak on my adventure:

It was a 100 cc rotary valve Suzuki with no trans vent. None.

The fix was to add an O ring to a slip over the crankshaft collar. The crank seal contacted the slip on collar, not the crank. The design relied on a Tight Fit between two machined parts to seal the crankcase.

And yes, I did spray the trans filler plug to look for leaks. None showed.

It was only after hooking the compressor with regulator set at 10 psi that I found it.

A hose into the trans fill hole placed to my ear let me hear the slight hiss.

This one took me days to figure out.

Once upon a time I was a young man working in a rough neck factory. I used all the modified four letter words I learned there on that pressure test.

Hope it isn't a leaky valve stem?? Clarence

Clarence, exactly what are you referring to?

I think he's saying to make sure your test rig is air tight and that the leak isn't outside the motor.

I did that today. I tested it on the 98 and didn't have any issues with it.

Too bad you couldn't submerge it like you would a tire tube to look for bubbles.....

Don't tempt me!

Um, it has been done.

Ed

Where the center cases come together is my guess. Pull the engine, tear it down and start over. There comes a time when all you are doing is driving yourself nuttier! Things happen! You do EVERYTHING 100% correct and you just want to cry! The engine in my Super Rat Shifted flawlessly . I rebuilt it inspecting every single part. Then after 2 hours running time it gave trouble shifting into First gear. I have 2 Ash trees in front of my Barn. Don`t ask me how but a leaf got in that engine, got ground up and found it`s way into the counter shaft! It was probably in the funnel when the oil was poured in. And I was the one that poured in the oil!!! Things happen! Joe.

So yeah, after doing the dunk tank test I can officially see the the leak coming from the breather! I tried putting soapy water with my finger but that didn't work. So I'm assuming my seal wasn't installed correctly or I screwed it up putting it in? Is there any other avenue for it to get there? So I guess I'll be tearing it down and getting a new seal. Throwchain, you were right all along! The sealant really took care of all the other gasket leaks. Thanks guys.

I went back and looked at the part number, for some reason I thought it was the same seal as my rat. So I put the wrong seal in.

Ouch, that hurts.

Fair amount of work there.

The only other possible area is the seal between the cases, around the crank area. The rear of the crank and the tranny cavity share a mating surface and if that's not sealed it could mimic a seal leak. There is a directional install to the seal, flat side should face the crank.

Yes, it is but its my own stupid fault for not making sure I had the right seals. Does anyone have the size of that seal off hand?

When you guys seal your cases does every part of mating surface get sealant? I want to say that for some reason I didn't put any sealant on that part. Not sure why, I got a lot to learn here, good thing is I usually learn from my mistakes....usually.

I'm not convinced the seal is the wrong one. And yes sealant on all mating surfaces. And you don't need or want a lot of it, just a light application to fill in any gaps.

I didn't seal around that area it could have leaking through, do next time around seal all surface and should I replace the seal right away since its apart?

As long as it's apart replace anything you think may need it.

So are seals for the right side crank the same size as the ones from my 98 because that's what I was going off of. The part number for that seal is different. Does that affect the size?

So the finger held on the side of the transmission breather is just a home-cooked way to attempt to assure that a water/soap film gets formed completely across the hole in the vent piece so bubbles will form. I should have mentioned that . . . and that several tries should be made. Perhaps a better method would be to use a flat artists paint brush (under a buck at Walmart) dipped in the soapy water then held over the transmission vent hole. Oh well, that time has passed.

Now you know there is a leak from the crank cavity to the transmission cavity . . . but you don't yet know WHERE the leak is. If you have the clutch cover and clutch removed, you can turn the engine on its side and look for bubbles through the oil in the clutch side main bearing (pour some more oil in the bearing if needed). Got bubbles through the bearing? Now you KNOW the seal isn't sealing. No bubbles through the bearing? Dang! The leak is somewhere else. Usually between the case halves . . . but it could be a porous case condition.

Yes, the complete "web" of matching case surfaces must be sealed (lapped first???). You can use silicone sealant (lots of folks will roll their eyes at that - but I used it in the PABATCO/Hodaka Service Dept. shop back in 1971 . . . and didn't switch to the new fangled anaerobic sealant until a couple of years ago) . . . but I digress. Ennnnneywayeeee, a very tiny "thread" of sealant along the center of the "webs" is needed. Keep it small - say 1/3 the width of the case web thickness and about that same height. More is wasted . . . and squeeze-out of big globs on the inside is not a good thing.

Ed
PS: Silicone sealant and anaerobic sealant clean up is easy at the time of initial use AND later when ever the cases are split again . . . unlike some highly favored sealants with names ending in " . . . bond" which I've found to be very messy initially and a royal pain when re-build time rolls around. (my 2 cents)

Ed, I already had checked with clutch off and on its side.....no bubbles. There was a small area around the cavity and the back side of the crank that I didn't touch so I'm guessing that's my leak but porous could be it too. So I guess I wont mess with the seal I have in there if it passed the no bubbles test. I'm still wondering if that seal the one from a 98 is still compatible with the 01. It's a different part number and doesn't show compatibility on the list. I did use yamabond on the 98. I'm not sure what the fuss is with it. It seems like it stays fairly flexible.

No, there was no lapping done to the cases, I'm not familiar with the process. Is that something you do yourself or at a machine shop? At any rate, I think I'll try cleaning everything up and then resealing everything this time. I'm pretty sure I did that on the 98 and I had no big issues. I'm thinking it was just another rush to get done and that's what I get.