that they do, but not sure with a gazillion HP Engine the size of a buick in the back LOL

You said you drove it and it topped out at only 35-40mph...
...was that at full Engine RPM?
...And were you in the "low" gear or the "high" gear?

The Hondamatic has a low and high gear, that's it. Top speed in low was 60mph and 105mph in high. Also, the CB750A with the Hondamatic boasted only 39hp @ 7500rpm. Hence...I don't really understand the benefit in putting this powerplant in place of the stock Engine (??).

Looks like the gearing from the Engine through the sprocket-train is unchanged since you've got a sprocket size "A" coming out of the Engine, driving a size "A", steps up to a size "B", but then the final drive sprocket is back to a size "A". Hence, -0- net reduction through those sprockets. Looks like a 14T and 28T sprockets (tough to see)...

> Engine 14T to 14T jackshaft, 14T jackshaft to 28T jackshaft, 28T jackshaft to 14T gearbox, then gearbox 10:1 reduction.

> Math: Engine gearing x (14/14) x (28/14) x (14/28) x (10/1) trans = Engine gearing + gearbox 10:1.

The motorcycle also had a REAR SPROCKET though. Stock rear sprocket on the CB750A was a 42-tooth. So...a 14T drive sprocket to 42T drive sprocket is a 14/42 or a 3:1 reduction.

Tire size differential could be considered null...CB750 rear tire is 130/80 on a 17" wheel = 23-24" and considered the typical tire OD on an Oddy.

Weight isn't horribly different since the hondamatic 750 weighed 560lb.

So the bike's setup would reduce the Engine RPM down 1/3, and the Oddy gearbox is reducing Engine RPM down 1/10. Hence your buggy is 70% slower than the bike (but more torquey, lol). And this could explain why it only topped out at 30-40mph!!!

Slower, heavier, still air-cooled, and required a tank & jack-shafting...besides it being an easier to maintain 4-stroke and having a "granny gear", I really don't know why they did this swap.

In theory you'd have to sacrifice some torque and put a bigger sprocket on the Engine shaft to get more top speed. If you could find a 20T drive sprocket and it'd fit, and use 13T on the jack shaft/gearbox, you could improve the output RPM by 1.5x (~~20/13). This would get your top speed in 'high' out to 50mph, but have no idea what would happen to torque, low end, nor chain life. A 22T / 13T combo would maybe get you to 55mph in high gear.

Or...just rebuild the stock Oddy Engine and use it.

In the end, you've still got your money's worth or better in Oddy parts alone. So, don't sweat it!!

It wasn't at full rpm, the throttle was only going about 3/4(I have to adjust the throttle cable). And that was shifting through both, also don't forget that the carbs need to be synchronized and tuned.

Yep, I guess I was looking at that wrong and was halving the RPM right after it got doubled. Now I see it correctly (was sketching on my whiteboard at work earlier, lol). So that makes it 60mph or so. Glad I was wrong!

Ok, now I want to see/hear this thing at full power. Although I have my doubts since the late 70's early 80's powerplant doesn't make all that much more power than the stock Oddy. Find a newer bike Engine that's 65-100hp and make it a superbike shifter-Oddy!!

There's a '76 on evilGay for $499 without any electrical.

in my odyssey I am converting a zx600 Engine

a 583 rotax has gobs of power for a small car like that, the Farr off road kit looks to be the way to go! Dave-co will be installing this kit into one of my long travel pilots, lots of pictures when I start

You've got the jackshaft setup already there, so a bike Engine might be a simple near-drop-in. If you can find a fuel-injected GSXR, CBR, etc bike Engine with everything from the rice-pipe to the dash gauges and with the entire wire harness, computer, carbs, intake, fuel send unit, etc. A wrecked bike is a great source. A carb bike is fine, but for a couple hundred $'s more you can simplify with EFI. Look for something you can see/hear RUNNING. You can pick up a '96-03 GSXR 600 for fairly cheap and they put down 90-100hp (97-00 carb 90hp, and 01-03 EFI 100hp) which is pretty much as much as you want to put through a stock FL350 gearbox without losing sleep. Anything newer starts to get pricey to the point where you could just go buy a clean running Oddy or decent Pilot instead.

What scares you about the 2-stroke? Just have to set them up right, break them in right, and maintain them. Its not high-tech! Something breaks on a 4-stroke, and you're pretty much sunk. 10x the parts in a 4-stroke.