The Hodaka Club Forum

Vic:

Something else is most likely wrong - this doesn't sound like a sealant failure.

Yamabond or RTV or purpose made anaerobic sealant should be applied in quite sparing amounts - a continuous but sparing application. When you tighten the case screws, the seam comes together and presses almost all of the sealant (of any type) out. The sealant left in the seam/joint is quite likely less than 0.001" thick when all is done. Putting on more sealant only increases the amount of "squeeze out". The "squeeze out" on the exterior of the cases isn't a problem except for appearance. The "squeeze out" on the inside is another matter. Chunks of it could come loose and wander around the engine. Even that may not be a big problem . . . on the other hand, it really isn't the best thing to be sending lumps of Yamabond/RTV/anaerobic sealer through the gears, into the clutch and the ball bearings and the kick start system needle bearings.

Your situation of losing all the oil while sitting in the garage, suggests that the cases never actually fully came together all the way around. A relatively quick way to check where the leak actually is would be to install a cylinder and head and do a leak down test. I'd guess that you will not be able to pressurize the engine to 6psi to do the test due to a large case leak between the case halves - but you will be able to see where the bubbles are (soapy water spray is used to find the leak). Doing the test may help you find what ever is preventing the cases from sealing.

The symptom reported does not suggest a sealant failure - it suggests either an assembly fault or a set of cases which need to be lapped to make the case sealing surfaces flat. Regardless of all the above, it seems sure that the cases will have to be split, closely examined, issues corrected and then reassembled.
Ed

As you put an engine together there should be a little side play in the shafts. Victor I taper a sucker stick down to about 3/16 wide and taper the tip down to a point. I apply just enough to be tacky. I am not applying a volume. I assemble the engine without sealer, to include tightening screws making sure everything turns and has a little end ( side )play. Then I split again and apply sealant The amount of yamabond is about a thread size that is uniform outside the case when everything is tight. Some people drive in a screwdriver to pry engine cases apart, everything must be inspected. When working from spare parts or on engines that others have rebuilt, look for extra thrust washers or incorrect ones. -----Clarence

Clarence. I used a snap blade knife to apply the Yamabond. It was applied very evenly around the edge of the cases. The cases went together smoothly and evenly and I could see a small bead of bonding agent all the way around the case joint. I wiped the excess bond off gently and let it dry. So I didn't think there was a failure of the cases to seat. I also used all new case screws because I sit there want the issue to be that the case didn't pull together closely enough.

I'm guessing, just buy "eyeball measurement" that I put a fairly even sealant bead on about 1/16" all around.

I don't have a way to pressure test at this point. But I'm going to pull it apart and inspect it to make sure there wasn't an area or two where there wasn't enough seal. If I don't find any missing seal spots on the cases, I'll strip the Yanabond off and give it another go.

Sometimes I just need to verbalize what I'm seeing to give myself a chance to think about it more. I'll let you know how it goes! Thanks! ; D Victor

Vic are you sure that your oil loss is coming from the seam at the case halves. For instance did you mount the engine sprocket and tighten the nut? That might be a more likely culprit. It sounds like you did everything right putting the cases together. Good luck locating the source of the leak!

That's a very good observation Ivan. If the sprocket collar, sprocket and nut (tightened) are not in place, the transmission oil has a free-flow route thru the ball bearing to the outside.
Ed

Ivan. I'll check. I'm pretty sure I put it on, & securely, before installing the shifter cover. ; D Victor