85 Marathon Electric to gas

[bronsonj]

I just bought an 85 marathon that an 18 year old was going to convert to gas. I picked up the fairly complete cart and a new honda 6.5hp clone motor from the kid for $20! And that is not a typo!

I already have a Comet TAV2 "torque converter" laying around.

The rear brakes work, the rear diff doesn't leak, the steering seems tight and the frame is solid. It is as ugly as a monkey's hind end.

I am thinking I need to weld together a mount for the engine and a plate to mount it to so it will stay in-plane with the rear diff and the chain won't go slack when it hits a bump. I need to remount the gas tank and add a small fuel pump. I need to move the muffler so it won't catch the seat on fire. I have the #41 sprockets and #40 chain that I would need already. I don't think this will be an overly difficult project.... Time consuming, but not too bad.

Am I just missing something overly obvious here? I know it won't have reverse, but I don't think that is much of a concern.

The kid I bought this from had no real tools and no ability to weld. I am not a pro, but I am certainly no noob when it comes to metalwork. So, before I start spending my nights working on this thing, is this a fools errand? Doomed to failure from the start? Thoughts or tips would be appreciated.

[pachanga90]

Welcome!A couple points.With the stock rear,you will not have reverse(It weighs about 400-500lbs,you don't want to wrestle it in a spot you can't turn around in!).The original engine in that cart is a 2-stroke and it runs backwards for reverse.Yes you could build a plate to mount the engine and jack-shaft for the CVT,but I don't think that Comet CVT will last very long,as its' meant for a Go-Kart,Mini-Bike,etc..that are much lighter weight.I would either try to find a stock donor-cart,or find a 4-cycle Marathon Rear-Axle(1990'-94')Bolt it to your swing-arm,build a mount,and install your engine that way.You will be much happier in the end.Hope this helps.

[scottyb]

6.5 hp am I missing something? Stock 4strokes were 9 & later on came 11 and 13hp motors

[bronsonj]

Thanks Pachanga, I was wondering how the Comet would cope. My in-laws have a dead gas cushman. I will see what I can scavage off of that when I am up there in a couple weeks. If no parts are slavageable from the cushman, how much *should* a decent gas rear diff/axle cost? They seem a bit steep on some auction sites I have looked at.

Hi Scotty, I wondered the same thing. I did see some youtube videos of some guys doing the same thing and it seemed to scoot pretty good. Better than I thought it would anyway. If I were buying the engine new, I'd have opted for the 11hp clone instead of the 6.5. But this came with the cart for twenty bucks so I thought I'd try it. The kid removed the governor so I should get 4500 RPM out of it which should help some.

[mtpolarbear]

Welcome to BGW!

[tradermark]

Try posting down in the Gas EZGo section. There's a guy down there who's already done this, probably where the kid got the idea in the first place. Lots of valuable in down in the Clone Engine Swap section too.

Hope this helps.
Mark

[pachanga90]

I didn't notice the 6.5hp,I wouldn't waste the time on that.Way under-powered.I would start at 11-12,no less considering stock 2pg is 8,the newer carts are in the 9-12 range.

[bronsonj]

Thanks for the welcome MTPolar.

Mark, thanks for the heads up. I will look in the Gas section.

[pachanga90]

The Big-Block or Swap Threads will be your best bet.Mine is a 85' Marathon in a TXT-Body,with a Opposed Twin Briggs and Yamaha G2 rear-axle.

[bronsonj]

Thanks Pachanga, another 85 marathon that's been converted! Nice to see.

I'll hold off on getting the 11hp until I can see what the old cushman cart can give. I really don't know what's wrong with it, but it has been sitting under the oak trees for at least a few years. I might get a good axle out of it or maybe even a usable engine or trans. I think the bigger cushmans used a real transmission, not the CVT belt style I was planning on.