The Hodaka Club Forum

No, the breather fitting vents the transmission cavity. Crankcase breathers on 4 stroke engines are a different animal, for a different purpose. (Um, your own pressure test shows that the breather isn't venting the crankcase . . . right?)
Ed
PS: Fly fisherman perchance?

Ok, apparently or obviously I'm not seeing this cavity. But I'll trust your assessment. I'm more of a walleye guy. I live on Lake Winnebago in Wisconsin. So I do a lot of jigging, slip bobbering, and mostly trolling. We catch a lot of different species. Walleyes, Sauger, perch, crappie, gills, white bass, burbot, sturgeon, etc...great system to fish. Oh I forgot to mention the pesky sheepshead!

I think the breather fitting everyone is talking about is #19 in the previous schematic. And the cavity Bullfrog mentioned is the cavity underneath the breather which is a part to the transmission cavity. I don't fish but I know what Bullfrog is talking about.

Bill nailed it. Item #19 in the parts diagram for the Super Rat 98 is the transmission breather vent. While it is located very close to the crank cavity - it does vent the transmission volume/cavity directly.

Using tunnel vision, I did make a mistake in my post last night. My tunnel vision was imagining what would happen in a pressure test if the breather vent actually did "vent" the crank cavity. If that were the case, you would not be able to pump up any pressure for the pressure test at all. Every pump would come whistling/wheezing out of the breather. So (my thinking was), since you didn't experience that situation, you have proof that the breather does not vent the crank cavity.

HOWEVER, I have pressure tested engines with a fully blown clutch side seal which DID whistle/wheeze at the breather vent with every pump - because the leak "path" was so large and free flowing that the engine could not be pressurized at all. In fact, with your engine during a pressure test, I'm sure that soapy water sprayed on the breather vent will reveal a leak (bubbles will form at the outlet hole). Those bubbles tell you that air pressure in the crank cavity is leaking into the transmission cavity - but they don't tell you how the air is leaking. Faulty seal? Leak between the cases? Porous case castings? Etc.

The transmission breather vent assures that as the engine heats up (and the air in the transmission cavity heats up and expands too) - the heated air can escape. Without the vent, the heated higher pressure air would be forcing oil past the countershaft/sprocket seal AND pressing the outer lips of the crankseal tightly onto the crankshaft which would probably wear it out more quickly. The clutch cover gasket would also be under pressure.

Hope these additional comments are helpful.
Ed
PS: I guess I won't pirate the thread into a discussion about fly fishing then. (and I don't know a thing about walleye fishing )

Ed, Thanks for all the information. I understand most of it but I'm not all of it. Is there a rebuild kit that would hit most of the key parts that I should change if I start breaking it down? I don't want to cut any corners but I also don't want to do too much. I still think I should wait to run it, see how it runs. I know the clutch plates are probably sticking right now so I've read up on ways to break them free. I still want to do that because if it doesn't work I will I will be also replacing the clutch. Good news is, the bike isn't going anywhere so I will have many years to restore it and get to know it. Thanks again to everyone for there info. If it wasn't for forums like this I would be lost!

Shaun

Shaun,
I have several thoughts. First, you are off to a great start in learning everything that you need to know about your Super Rat. I believe that you are going to find that these bikes are very easy to work on and like Ed stated, once you do a rebuild, you will know your bike inside and out.

I also think that you have the right attitude to successfully get your bike up and running. Yes, it takes time and money. It also takes a handful of specialty tools. That is the bad news. The great news is that there are only a few of these tools to obtain and once you have them, you can work on your Hodaka whenever you please.

Yes, there are kits available for seals, bearings, gaskets, o-rings, case screws, etc. Both Paul here at Strictly Hodaka and Dan at Hodaka-Parts carry everthing that you will need.

So you have choices. You could split the cases and check everything out and just replace the rubber parts (seals and o-rings). Or you could replace all of the bearings and bushings too. Your clutch is easy to get to at any time. Also, I should note that you have to consider the top end and what to check and replace there should you decide to tear it down.

The bonus that you have with this Hodaka forum is that you have not only former Hodaka dealers on board, but also several of the original PABATCO (Hodaka) employees. Ed (aka Bullfrog) was the Service Manager. You just can not do any better than that! These people are ready, willing and able to help you through whatever you decide to do.

Take your time and it will be a great experience.
Dale (a newbie less than 5 years ago)