Combat Wombat max HP or torque

[keif149]

Greetings,

Great to see so much support for these great bikes!

I'm doing some research on the early 70's mx bikes and wondered if any one can tell me the max horsepower or max torque for the Combat Wombat 125cc. Any or all years that you know of would be greatly appreciated!

Many thanks in advance,
keif149

[hodakamax]

It was all guesses in those days, no ratings or dynos, I think we all just made things up, wishful thinking of the times!

Maxie

[Bullfrog]

The standard Hodaka answer to the question, "How much horsepower does it have?" was, "Enough".

Several of us could give you a pretty good ball park number without the advertising agency inflation factor, but you'd probably be disappointed. So you'll have to either accept, "Enough" or go out and ride the machine and come up with your own number.

Ed

[Zyx]

Oh, I think Hodaka had a very good idea of the hp and torque of each of its machines. You may note that some of the earlier bikes were rated, and even those that are not do state at what rpm each value is maximized. It would be problematic to state with authority that max torque is reached at 8,000 rpm without also having an idea of what the peak output was. If you weren't tracking it on a dyno, how would you know when it peaks?

In the early 70's the Japanese manufacturers were having a bragging rights war that got out of hand IMHO. Nothing Honda or Yamaha said about peak hp was true (and I worked for both between 1974 and 1977), especially when talking about racing equipment. Hodaka routinely made slightly less power in factory trim than the Big Three, so there was no good marketing reason to say what that number was. It would only impact sales negatively, even though the reality was that Hodaka's hp and torque were roughly in the ball park with the others. The difference between 17 and 18 hp is moot at best. It was just that Hodaka would have to make things up to match or beat the lies coming out of the Big Three, so why go there?

And even some local shops and race types had or had access to dynos, so it isn't correct to say no one had such things. The better point was that it didn't matter. Motocross races aren't won on raw horsepower, or even on torque. It is far more complex than that, and depends greatly on who is riding. Admittedly, raw power helps define results in drag racing, but otherwise, not so much.

So it doesn't really matter if a CW made ten or twelve hp or whatever. If you ride one and it makes you smile, how much more do you need?

[fullchoke]

Getting the power to the ground and using it is the formula for success. I remember Can AM had a 250 back about 1977 that made a huge amount of unuseable HP. I remember the factory rider refused to ride it. Black Widow.
I have not ridden a Hodaka 90, but I have ridden a Honda 90 which my dad had. I bought a 1971 Suzuki tc90 so we could ride together way back when, and I'll tell you that little Suzuki with that rotary valve induction would really take off. The Honda couldn't keep up and was outclassed big time in the power dept. but look how many Honda 90's they made in comparison.
Hodaka had the Ace 100 and the Super Rat, Hodaka made them both at the same time, I'm curious about the engine specs differences between them and the list price too.

Greg

[hodakamax]

Hey Greg, By the time the Super Rat came out we had all the modifications in place on the Ace 100s through Hodaka and aftermarket people like Webco and Bassani. The Rat finally put everything in a cool package and was the start of the real racer in a box. The price change was small but if you wanted only to race it was ready to go. When we raced Ace 100s we had already replaced the head, pipe, piston, carb, tires and gearing. It took the big guys (Honda,Yamaha etc.) years to figure out the package racer thing. It was a good era for Hodaka until the big guys finally got it.

A little history here.

Max

[keif149]

Thanks men for all of the replies and taking the time to answer.

Claimed numbers were actually what I was wanting and I hoped they would be in the owners or a shop manual.

The last year I raced 125s was in '74, but not on a Hodaka. I moved up to a 360 Pursang in '75, then switching to Maicos in '76 with a 400. I stayed with Maico with other 400s and 440s and stopped racing in '85 with my last 490.

So, trying to remember '74 and some open practice sessions after that when 125s were on the track at the same time as the Open class bikes and if I had to guess, I'd wager 16 at the real wheel and that would probably be about 21 claimed for the CW.

Again, any claimed numbers would be great. I only mention torque as a few brands would say what torque they claimed at XXXXX rpms and I would use the old formula of torque x rpms divided by 5252.

No dire emergency, I'm just making a spreadsheet for my own amusement.

Thanks again,
keif149

[hodakamax]

It would be interesting to dyno some vintage bikes both stock and modified to see what mods did. When Hodakas first arrived we were modifying street bikes to race. Incredible gains were made from stock. It was a fun time but all we had was the seat of our pants to judge things (or compare it to an unmodified machine.) Dynos for motorcycles were probably around in the late sixties but were only a dream in Kansas. (Actually not much has changed since then in our state.)

Just thinkin' again!

Maxie

PS--I was a Maico dealer in that time and raced 400s but I always liked to race Hodakas best! Did you ever see a 125 Maico with a rotary valve? They were fairly swift!

[Zyx]

Keif,

Hodaka made no number claims for the Combat Wombat, and if Ed, who was part of Pabatco, says they weren't published, they weren't. I would seriously doubt the CW made even 16 at the crank much less at the wheel, nor would I expect a 25% power loss through the transmission, but I suppose it's possible. Only way to know would be to rent some dyno time.

The published data for the Ace 90 was 8.2hp @ 7,500, and 5.1 ft-lb @ 5,500. Ace 100 was rated 9.8hp @ 7,500, and 6.7 ft-lb @ 5,500. The 100B was rated at 10.5hp @ 7,500, and 6.7 ft-lb @ 5,500. The B+ was probably the same as the B model. Hodaka does not say whether those are crankshaft numbers or wheel numbers, but the Japanese not being Germans by disposition, they are probably crankshaft numbers.

By the time Hodaka started making crate racers, the marketing wars were heating up, and Hodaka stopped publishing power output numbers. The Super Rat chrome tank is rated at "sufficient" hp and max torque at 6,600 rpm. While that doesn't tell you what the torque is, 6,600 is a fairly specific number. And, since Hodaka did know what the numbers were for earlier models, one may assume they did for the others as well, but simply would not state them. The business model was built more on durability and simplicity than on statistics, and certainly Hodaka pride would not have allowed for wild BS claims of power, just to hope to impress some youngster looking for an MX bike of the day. Clearly, it is possible to get much more power from a Hodaka than the factory did, but the cost of doing so would have jacked up the price. Price point was one of the major selling points of the Hodaka.

The published numbers for the 90 through the 100B's suggests both a range and a trend in power. If the 100B made 10.5 hp, the model 93's probably made a bit more, like 11 or 12. The 125's in modest port trim made a bit more, but not a lot, say 12 to 14 more or less. The Super Combat, ported as a dedicated MX race bike, no doubt made more. Perhaps 15 or 16hp. The CW was not a balls to the wall race bike. I would expect perhaps 14hp at the crank, but I don't really know. You can get more than that from it, but you have to modify it first.

Bottom line is that while the Big Three did publish numbers, they were largely inflated by virtue of some primo Asian recreational products, and if rated fairly on the basis of dyno runs, you would find that stock Honda Elsinore numbers for 74 or thereabouts would be very like Super Combat numbers, and if higher, only be a digit or two. Such small differences don't mean anything to the average sportsman, and the factory guys were not riding stock bikes anyway.

If you want to get 21 crank hp out of a Wombat, I suppose you can, but you will also get the benefit of a life span similar to any other works bike, and rideability will suffer for all but the better riders. If you are one of these folks, feel free, although there are better starting points for an all out power effort. The CW is a durable and rideable woods bike with lots of potential. I say ride it and enjoy it, and if you then feel the need to tweak it, do it. We have all tweaked our bikes at some point. It is an honored Hodaka tradition.

[racerclam]

Harry Taylor told me the Super Combat made 16hp and the same year Honda Elsinore made 15hp but the Elsinore made faster lap time due to the 6 speed trans. I have no info on the combat wombat

Rich

[kc57]

In the Reed Valve primer article from Popular Cycling ( on the front page under ads, articles and videos) . It show's dyno runs for a Combat Wombat. It looks like about 12.5 hp @ 8500 rpm . With stock engine and soundmaster ?? pipe. With a reed valve and stock porting almost 14hp @ 8000 and finallly With boost ports 15hp @ 9000.

Pretty interesting article . But I cant say I have ever heard of a soundmaster pipe. K.C.

[DGardner]

Had some dyno time on my wombat yesterday. This is with a 03 cylinder with stock height ex with only some intake work by RK Tek, 28mm pwk, circle f pipe, RK Tec head. The run was started at 3500 rpm and ended at 7500 rpm the first run was without a hole in the back of the piston for the reed valve and the second one was with the hole, almost a 1/2 hp with the hole over no hole but with less HP and torque in the lower RPM. The jetting is on the lean side on the bottom and about 5000 rpm. First I need to say this was made for the street it's not a race motor that said check out the flat torque curve and that is what it feels like on the road and what I was looking for. If you live close to Ogden UT and would like to put your bike on a dyno or need a custom pipe made for your bike give Tim at TTR Designs a call 801 920 5083. DG (all this is at the rear wheel)

[Zyx]

I find it fascinating how little difference it makes using a windowed piston. If you could add either a photo of the modified piston or a description of the hole arrangement for reference, that would be great.

But frankly, if using a windowed piston only gets you a tiny increment of power across the band, and no visible benefit at any rpm ( no sudden peaks ) then small adjustments to boost port center braces won't even register.

What style rear tire did you use for this run? Stock carb or not? Hodaka reeds or carbon fiber?

[DGardner]

The hole is in the center about 1/2 inch above the bottom of the piston it is about 5/8 inch wide and the same hight as the new wisco piston. The carb is a 28mm pwk with the reeds that Rich sent. The tire is a 3.50 universal.

[Zyx]

Stock Super Combat

The window at the top of the piston makes best use of the V porting on the intake side. The multiple round windows were traditional, and do make use of the intake porting on the 03. They are not aggressively large, but round is a strong configuration in terms of stress resistance, and combined area is more substantial than it might appear, not to mention that configured this way, some part of the intake and V porting is open to transfer through just about the full stroke of the piston. Without the top window, you will be missing a lot of transfer potential, plus that top window causes flow across the bottom of the crown, adding to cooling. It might be worth considering adding such a window if you don't have one now.

[DGardner]

I have the horizontal window in the piston.....it started out as a combat wombat wisco piston.

[DGardner]

Also as I said earlier the intake has been modified and looks nothing like a 03. That is why the hole is in the middle of the piston.

[DGardner]

The first piston is the new one with the holes I add and the second one is my old piston.

[Zyx]

Curious to know what intake mods were made, and if you could, explain the theory behind your hole pattern. Thanks. BTW, the holes appear to be ink not drilled.

[Bullfrog]

I too am interested in the hole pattern shown . . . haven't seen that before.

I also have never seen a piston like the "old" one in the photo. It looks like about half an inch of piston above a single conventional ring . . . strange.
And the wrist pin is at the lowest location in the piston I can recall . . . I'm sort of stumped as to how that could have worked in a Hodaka engine.

Ed

[bchappy]

Appears in the photo to look like the piston is made of wood.

[DGardner]

It is wood....I seen these on the internet and got a laugh out of them.

[DGardner]

Just for fun this is my other bike that I put on the dyno today. This bike is a 2010 1900 cc yamaha stratoliner......no turbo.

[Zyx]

I too am interested in the hole pattern shown . . . haven't seen that before.

I also have never seen a piston like the "old" one in the photo. It looks like about half an inch of piston above a single conventional ring . . . strange.
And the wrist pin is at the lowest location in the piston I can recall . . . I'm sort of stumped as to how that could have worked in a Hodaka engine.

Ed

It didn't. More like a potato masher turned into a photo op. I thing someone is jerking our leash. I'll let you know by tomorrow if I am amused.

[Zyx]

Just for fun this is my other bike that I put on the dyno today.

Cute, but the Stratoliner has been out of service for a long time, and had a slightly different power curve. Being turbo-supercharged, it's power came on a bit slower than shown, but was fairly linear.

I suppose this means your first chart was just for fun as well.