Murray explorer gokart

[djfisher8]

I bought a rolling murray explorer gokart back a couple years ago. I took apart rebuilt or replaced the parts. I used a predator motor on it. The single tire pull didn't work to well in the yard. So I used a piece conduit and bearings and put a 1" axle on it.
It works well but eats clutches. I've checked alignment each time. I replaced the bearings with regular gokart bearing and blocks and still goes thru clutches. I've tried low and high end clutches. The predator is a 6.5 hp, 3/4" shaft. Used 35# sprockets and chains. It breaks the bushings in the clutch. When I align I used a straight edge on the outside of the sprockets then with chain on used it on the chain. It looks square. I did have to move the motor mount over when I changed bearings.I checked level and it shows level. I also used a adjustable plate for the motor to give it more adjustment than orginal mount. So I asking if anyone can give me a idea of where I'm going wrong. Grandkids like to play on it but it will only go for 3 or 4 hours before the clutch goes. Sorta at the point of using the motor on a mini bike and ebaying the gokart frame. An
Any suggestions is welcomed. Thanks!

 

[Havasu Dave]

I'm pretty sure that took a Comet 30 series clutch and driver. Belt drive system. A standard mini bike chain clutch is no good for the big, wide tires, and heavy weights. I'm assuming you removed all of that when you rebuilt it?

A quick way to verify what I am saying is to email info@maxtorque.com and let Jim know what your engine is, the kart weight estimate, the outside diameter of your tire and the width. He's very responsive.

 

[djfisher8]

Didn't have the motor or drive, had a wheel with a sprocket, the manual on line showed it with clutch and chain. The manual was close but not exact match to the gokart. But what you said sorta makes sense. I'm using a comet on a heald super bronc, know they work with heavy loads. . I had thought about a 40 chain and clutch, but figured it would do the same. Anyway I'll go back double check the manual again. Thanks for the thought.

 

[Havasu Dave]

Big difference between big bike and heavy go kart.

The general rule is "Go Karts with rear tires taller than 15" or an engine larger than 8hp require a torque converter."

 

[djfisher8]

Found the manual for the murray explorer, think this a early model. Sorta kids model adult has hard time fitting in it, two place. It did have a clutch and chain drive. Orginally had welded bolts for rear axles, with one side pulling. Did not work well in the yard. Live in the Ozarks there is no level place or very little. Went to solid rear axle it helped but still went thru clutches. The motor is 212 cc predator 6.5 hp and tires are 14" in the rear. Stayed with the same size tire even though I went to the straight axle. A torque convertor or comet set up would be hard to set up with the room it allows. But will think about it before quitting all together on it. Sorta wonder if a jack shaft would work, have them on the doodlebugs d30's for the grandkids. Thanks for the info.

 

[Havasu Dave]

If your earlier model didn't have a solid axle, then perhaps that is the difference- spinning half the weight. I don't think a jack shaft is going to do you any good, unless you are trying to reduce the gear ratio, and have no other means. Of course that means getting too slow for the grandkids maybe.

The weak link on those clutches is that bronze bushing definitely. I wonder if a TAV system would work. I guess the Predator crowd is using the Chinese knockoff versions, trimmed down, with some success. You still may have to move the rear drive sprocket down the axle a bit to fit it though.

Here's the one inch PTO version OldMiniBikes sells.

https://www.OldMiniBikes.com/torque-converter-1-bore-35-chain-clone-.html

 

[djfisher8]

Missed the email address for maxtorque, just sent them a email, I'll wait and see what they come up with.

 

[djfisher8]

I'll do some looking and see I have a plate off a comet set up I used with the super bronc. Give me something to do next few days take care.

 

[djfisher8]

Hey I've been emailing couple times to Jim at maxtorque. Found out like you thought clutch isn't the way to go. He said they(murray) had two models one with a torque converter and one with a jackshaft. This one must been a earlier model or something. I undersized the chain and clutch. Missed or didn't look close at the parts list in the manual. Anyway either torque converter or go back to single drive with jackshaft.
I may do some measuring and looking a bit, have a idea I'll pull the motor, (have mini bike frame that needs a new motor) and ebay the kart frame or sell the parts. Thanks for the info and direction. Should asked more questions early on. Like your Mopar had 70' roadrunner in high school. Simliar color.

 

[Havasu Dave]

Hey I've been emailing couple times to Jim at maxtorque. Found out like you thought clutch isn't the way to go. He said they(murray) had two models one with a torque converter and one with a jackshaft. This one must been a earlier model or something. I undersized the chain and clutch. Missed or didn't look close at the parts list in the manual. Anyway either torque converter or go back to single drive with jackshaft.
I may do some measuring and looking a bit, have a idea I'll pull the motor, (have mini bike frame that needs a new motor) and ebay the kart frame or sell the parts. Thanks for the info and direction. Should asked more questions early on. Like your Mopar had 70' roadrunner in high school. Simliar color.

Thanks for the results. Best of luck which ever way you decide to go.

 

[KingCobra]

Here is the rear clutch system on mine.

 

[djfisher8]

Thanks! Gives me a idea or two. Not sure if I'm if I'm going to which way I'm going with the gokart. Could have use for the motor on another project. May shelf it to later. But know I need to go to a torque converter set up. Its sort tight for one, but it is doable. Thanks again.

 

[djfisher8]

Plan to work on murray gokart this winter, know I need a torque converter. Question can you put the drive sprocket on the outside of the torque converter in the rear and spacer the belt drive accordingly. . I have lining up issue of little outside space due to brake. I may need to motor over
but trying to figure a way of not having to do that. Appreciate any help.