Otis S-71 Cart with Predator 670cc and Drivetrain Help

[DeStoriesAir]

I acquired an Otis S-71 golf cart that I completely gutted so I can repair/prep for a gas conversion.
I will be installing the Predator 22HP (670cc) V-Twin engine.

I am needing some thoughts on the drivetrain from everyone's experience to see if the rear axle is going to have to be swapped out. The shaft is 90 degrees to the rear axle and it appears that the most common shaft is parallel to the rear axle. Are there any clutches/transmissions that anyone is aware of that would allow me to utilize the existing axle? See images.

[raydhd]

You might want to look at my HD/Columbia cart swapped to Suzuki 440 cc FC sled swap in that section. It would appear that you will be dealing with a similar situation with that rear axle cart combo. They way to use the 670 would be to graft a 4 cycle engine cradle to that frame. I looked at that option BUT it would take TONS of fab work. It just makes more sense to start with a more suitable cart for the 670 swap. HOWEVER really different swaps make for interesting reading. Whatever you do good luck and have fun.

[slonomo]

I'm not familiar with that cart at all. It looks like that might be originally an electric cart? If so, that's not going to work very well with a gas engine. You'll have no reverse gear and you'll have to use a sprocket and chain setup, which is very complicated to build from scratch and they never really work nearly as well as a CVT setup.

You can upgrade to a different cart that was a 4 cycle type with reverse gear. That would typically have the correct transaxle you need. Or you can find one that just has the rear transaxle and swap it in there, although you would need quite a bit of fab work to get the transaxle to fit up to the suspension etc.

[raydhd]

The big question on using the present diff unit is there a secondary clutch unit that fits onto the diff ? It looks like the unit used on the electric HD carts. I am not sure if there is a way to change or add to the snout to use one. If yes remember no reverse without using some other method. Some have added a secondary starter to drive a reverse system. I did not attempt this as space was already very tight as you can see from pages 2-4 in my sled build. Another consideration is the final drive ratio. HD/Columbia unit was geared for the higher revving 2 stroke engine so a governed 4 stroke would have a limited top speed. There a quite a few HD carts with the single cylinder clone engines on youtube. All of them claim the 30 degrees tilt on the engine had no ill effects on it. So a quick recap I used the sled engine since the rpms would result in plenty of speed and since it has no oil containing crankcase the tilt would not interfere with it's lubrication. IF you can't add a secondary clutch to the existing diff to use a CVT drive system you might want to rethink this project.