Ace 100 Transmission in a Combat Wombat--Huh?

[DesertRat54]

Yesterday I thought I'd button up a Combat Wombat motor that I've been rebuilding. As I'd picked this up as a project from Mid-Ohio some years back, I wan't sure what I'd find, but I had allowed myself to assume that the motor would probably have stock components, or mostly stock, anyway. Then the First Rule of vintage bike restorations presented itself: Never Assume.

After cleanup, everything went together smoothly and uneventfully--until I found that the kicker wouldn't move without a great deal of resistance and the certainty that trying to move it was causing some real damage. I split the cases, cleaned off all of the 3-Bond, and did several "dry runs" after checking for obvious errors each time. I couldn't find anything that I'd done, but thought I noticed that the kick gear and the second gear on the counter shaft weren't meshing correctly. As I recall, these two gears don't line up perfectly anyway, but the kick gear seemed to be riding A LOT higher than the second gear. Also, there was almost no clearance between the kicker gear and the first gear on the counter shaft, and this was before installing the other case-half. After noodling on this for awhile, I started looking at the gears on the counter shaft, and at the main shaft itself. From first to fifth gear on the counter shaft, I had 35T, 30T, 27T, 25T and 23T. The main shaft tooth count is 10T, 14T, 18T, 21T and 23T. Sure enough, these were not Combat Wombat components; they were all out of an Ace 100.

So, after this lengthy tale (sorry) I have to ask: "What's the point in putting an Ace 100 transmission in a Combat motor? Is this some Old School trick that I wasn't aware of, or is this a "bitsa bike?" It seems these gear ratios are better suited for road riding, yet the bike this motor came in was set up for motocross. Has anyone else tried this? Mind you, the previous owner somehow got all of this to function in the cases he was using. Apparently, and for some reason, these transmission components won't work in the Combat Wombat cases that I've refurbished for this project. I don't know why, but today I plan to install the stock CW transmission in these cases and move on with it.

I'd appreciate any thoughts on this. Thanks.

[dcooke007]

Could you let us know what the serial # was on the engine cases you replaced? That would be a good start to determining how this came about.

Danny

[eichco1]

Hodaka gears have been known to grenade on occasion.

I picked up a 98 bottom end once just for the transmission.
You can imagine my disappointment to find ACE 100 gears in it.
A 97 I worked on had 95 gears in it.
Just part of the mystery when working on a brand that so many parts interchange.

The good news is that 94 or 95 gear sets are not too hard to find. Can't say that about the 97 gears.

I also picked up another 98 bottom end with a 99 cylinder and a 95 head.
It had a hardened 97 gear set in it. BONUS!!!

Mark in Illinois
#492

[DesertRat54]

I haven't run into as much of that as you have, Mark, although I purchased a Combat bottom end some years back with a 97 gear set in it. That motor is in my race bike--the one that I haven't raced in three seasons...

I solved my problem today by just putting a Combat transmission into the Combat cases, so everything is as it should be. It was a textbook installation; as easy as painting by the numbers. The Ace 100 episode was an interesting exercise, though. What I found most interesting was that the Ace 100 gears, stacked one atop the other, is the same height as a stacked set of Combat or Wombat gears. The Ace 100 first counter shaft gear is thicker, though, while the second or third gear (I forget which) is thinner to compensate. This seems to make sense. I found it interesting that you say you've run across a 98 bottom end with an Ace 100 transmission. That must have been underwhelming.

Bill in Virginia