94 Wombat Crankcase Breather - Why? + Pressure Test

[Simonkav]

Once again, I'm new to 2-strokes and Hodakas so please excuse the ignorance. I'm trying to get a 94 wombat sorted with not much luck. I've learned that crankcase pressure is pretty darn important, funny things these two strokes, so I thought - I'll run a pressure test. I hacked together a tester. Sealed the intake and exhaust, was using the plug adapter for the air in/pressure reading, found BDC and began pressurizing. Immediately, pressure would not hold. Hmm. So I let low pressure (~3psi) just run constant and listened/sprayed and sure enough, I discover there's a crankcase breather?

So now I'm officially baffled. I thought the case needed to be sealed yet there is a breather? Does the wombat produce enough case pressure that it needs a breather and still has enough pressure/vacuum to move fuel/air through the motor? For the pressure test, I assume I just cover the breather?

Thanks in advance.

Simon

[racerclam]

the breather is for the transmission which is NOT! tied to the crankcase , If its blowing air through it , its because you either have a bad clutch side crank seal or it leaking through the case halves into the trans.

Rich

[taber hodaka]

If your wombat has sat for years I would only guess it to be the seal clutch side .. or as Rich said the cases. -----------Clarence

[Simonkav]

Ok, that makes more sense. Even looking at the schematic, it looked as if it was leading to the crankcase. I suppose on closer inspection it's just at the very top of the transmission?

Regardless, cases or clutch side seal - bad news. Need to split them and rebuild. Yes?

-Simon

[matt glascock]

Yep. No way to reach the clutch side crank seal without splitting the cases. I've done it with a lot of advice and help from this forum.

[dirty_rat]

As mentioned many time before, if you are not too sure of your abilities to do this work, there are many on the board that can assist. If you list where you live, there could be someone very close by that can be of great assistance. It isn't a hard job, but if never done before it can be daunting. There are also many professional (semi-professional) Hodaka mechanics on the board that could do the whole job for you, for a reasonable price.

[Simonkav]

Thanks dirty_rat.

I'm located in the San Francisco Bay Area, CA. Knowing local contacts/mechanics would be great! I'm sure it's quite possible, even likely, I'll get in over my head at some point

I'm FAR from professional, but not totally new to small motor work. I am new to Hodakas however. Most of my experience to date is on old English twins. I've only done one full rebuild from the crank up. It went well, albeit with a lot of patience and a lot of support from a board similar to this. It took me way longer than it probably should have and maybe even cost me more in the end, but made me a better mechanic and most definitely, a better owner of the machine. I hope the same for this job.

[dirty_rat]

One of the first things you should do is get a Workshop Manual for your bike and read it over. I would suggest the Official Hodaka ones as they are the best. They made one that covers the Model 94 and 94A Wombats and the Model 95 Combat Wombat. Well worth the money. Once you have looked it over you will see the engine is MUCH easier to work on that an English twin, and parts are much easier to obtain (not Whitworth fasteners to deal with).

[Simonkav]

Indeed! I do have a manual, first thing I bought when I bought the bike. I’ve read through the teardown/assembly sections multiple times in the last few days to mentally prepare . Definitely a few sections that I assume will be more clear once the motor is apart in front of me. I’m hoping it will pretty much be seals/gaskets. I’ll likely do bearings while I’m in there. Bike has sat for a LONG time and beyond that I have no clue what it’s history is.

And thank the lord for metric fasteners!

[dirtsquirt74]

Hey Rich and Clarence

A Hodaka guy sold me on the mod of drilling out the breather and attaching a hose to it. I have been doing it for more years than I can remember. Would you consider this mod to be over kill?

Richard

[racerclam]

are you going to be riding in deep water ? If so then do it if not then not . Or maybe if road racing

Rich

[Bullfrog]

What Rich said. Back in the 1970's when I rode several of the ISDT Qualifier events, I took care to install a vent and tube for the magneto area to help assure that it wouldn't draw in water on deep water crossings, but I don't remember drilling out and adding a tube to the transmission vent. (probably should have). None of the bikes in my garage have had a vent tube added to the transmission breather vent -- cuz I pretty much stay away from deep water crossings these days.
Ed