motor swap (how big) and clutch question

[Jody400]

Hello all, couple of questions:

Just bought another go cart. Pretty good size yerf dog, only paid $100 for it and i only had to replace the carb. It appears to be the same as the following link:

http://cf.mp-cdn.net/fb/31/3108b6c4e02372f3e5b6b9a86ba1.jpg

This only has a 6 hp engine and i want more power. I plan on using this engine on a fourth go cart that is awaiting an engine. I have found a lifan 15hp at home depot for $250. I believe this is the best deal. There is also a briggs and stratton 11.5 for $277. What size or brand would you go with? I honestly have never had good luck with a briggs. I recently purchased a generic baja from tractor supply that i was very pleased with so i am not too nervous with going with an off brand but i do not know anything about the lifan engine. The baja is on another go cart of mine. With this type of go cart what types of speeds would i expect with the 11.5 or 15 hp?

secondly, the current engine has a 3/4 shaft on it. This type of go cart has the belt and chain setup. i do not know much about these because i am use to the simple clutches.
The new engines that i am looking at all have the 1 inch shaft. Am i just able to buy a new clutch that is a 1 inch for the shaft coming out of the motor? How expensive is this? Can someone send me a hyperlink with the part i need? I assume this go cart has two clutches. One that is connected to the shaft coming out of engine that is belt driven and the other that connects that belt and chain together. Is it possible to eliminate one?

thanks in advance, jody

 

[Russ2251]

Speed and horsepower cannot not be equated.
3600 rpm is 3600 rpm...whether it is 500hp or 2.5hp.

 

[r_chez_08]

Speed and horsepower cannot not be equated.
3600 rpm is 3600 rpm...whether it is 500hp or 2.5hp.

True, however the 500hp could be geared for a much higher top speed.
The lifan is fine if you are not worried about a brand.
They make well known clones and other motors.

 

[Russ2251]

the 500hp could be geared for a much higher top speed.

OP made no mention of this. My comment would have been far different had he said so.

 

[slideways]

I once put a 16hp Clone (which is what you're looking at) onto one of the suspension 2 seat Yerfs. I had to use the clutch off of our race car since my belt drive setup i home made didn't work.

Geared 6:1 (60t/10t clutch) with 16" tires it was ok on a flat stretch but wouldnt climb hills well. The clutches hold up great but it was just too much stress. Powerslides and such were effortless though.

I would gear it higher if i did it next time. I would have really liked to run a jackshaft too. I had to hang the clutch on the end of the shaft (they dont slide through) and it seemed like alot of stress on the crank. Plus it would have given it more teeth on the chain to grip... this way was more like a triangle of drive vs wrapping the chain a little more around the clutch sprocket.

The clutch you are after is some type of 1" racing clutch. Noram is your best bet. I run an Enforcer 1800 series. They are about $180-200 new. You can also find others though...

Mounting the motor wasnt too difficult. I just removed the whole torque convertor jackshaft plate and mounted the motor to the existing plate.

 

[speedshopmike]

jody,
yes, you can buy a 1 inch bore driver unit (the effective clutch for a cvt) for your (presumably) 30-series comet cvt, but the 30 series is only rated to 8 HP.
i think they can hold more than that but i've not tried myself (yet).
anyway, they can be found on ebay.

there should only be one clutch type part on your kart, which is the front, smaller pulley of the cvt.
the rear, called the driven pulley, and sprocket ride on a jackshaft.