newbie needs help with gear ratio

[miniclimber]

i have a go cart with a jeep body on it with 22 inch mud tires. i am wanting to use it for trail riding and hill climbing. and i am wanting to use a centrifical clutch cause its easier and cheaper than a torque converter. waht would be the right gear ratio for this using a jack shaft. also what size sprockts need to go where? sorry i kno its alot for my first post. thanks in advance

[metalstudman1]

Welcome- What type/size motor? Any suspension on this kart? Also your wieght will be a big factor on if the centrifical clutch will last. Can you post some pic's of it?
Just to give you an idea of what you might need-
To get any type of climbing ability you'll probably need 9-10 tooth on the clutch, similar on the jackshaft & 50+ tooth on the axle.

[miniclimber]

it has a 5 horse briggs and a torque converter but the belt slips when climbing no suspension. i weigh about 130 pounds. and how do i post pictures

[metalstudman1]

Posting Pic's-
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You can always read FAQ as it provides lots of information too.

If you can take a pic of your CVT system(belt drive)- we can probably help.
A centrifical clutch may be cheap to buy but won't last or perform anywhere near as good as the CVT. Your monster size tires (especially in the front) require a good amount of torque to move it on flat ground.

[miniclimber]

this is it

[T3beatz]

Nice looking Go kart/jeep. For any kind of real trail riding I would recommend selling that and buying a nice mini buggy... they can be bought for a lot cheaper than people think if you stay in the adds. Having no suspension on trails will take it's toll sooner or later, either on the kart or on your bones!lol or if you have any fab skills you can add a simple swing arm in the back and some A-arms up front with shocks all around, for a little more comfortable ride.

The sprocket on the axle looks to be kinda small, you should find a bigger one and try and fit it on there... also if the driven clutch on there is only a 6" one you can get a 7" one for a little more torque on the low end. Doing those mods will take a lot of the work load off of the belt and engine, you'll spin more RPM's on the low side but it would climb hills a lot easier.

[metalstudman1]

It say's "4x4" :rofl: nice looking kart/Jeep!!!
I think the axle sprocket from what I can see of it is plenty big or couldn't be increased very much due to ground clearance- the sprocket on the jack shaft could be MUCH smaller to get any torque. I agree with T3beatz about the 7" driven but there's very little room right now. If the jackshaft sprocket was decreased it may allow enough space for the 7" driven assuming that it's not already a 7" now. What size sprocket is on the jackshaft? I think with the size of those tires if they're running on low air pressure you might have a semi-soft ride in the trails- but a continous beating on rough terrain will cause a frame failure.

[T3beatz]

I don't know MSM, my sprocket on my manco intruder was much bigger than my driven, and his looks to be smaller... I know it was a #41 size, but I don't know the sprocket count, but I do know it was huge. That's the only way i was able to drive it through most of the ATV trails. My bro had a smaller sprocket and bigger wheels and he couldn't make it through anything! lol

your setup is very cramped so, mods will have to be thought through, but if there is a will there's a way!

[miniclimber]

i have to take the body off the frame cause i stripped out the crankshaft bolt hole that holds the clutch on i was gonna clean it out and try and retap it. would this work and hold. and while its off ill measure the size of the pulley and count the teeth on the jackshaft input and out put sprocket and the axle sprocket.

[metalstudman1]

Re-tapping the hole will require a good quailty tap-It will work- the bolt usually get's stripped since it's much softer material than the crank shaft.

T3beatz- I stand corrected!!!!! I must have had a brain fart, the jackshaft sprocket would need to be larger for more torque- but there's no room to increase it. The big tires are killing the torque.

Check and see if there's room to increase the axle sprocket as that's the only place to make an adjustment for a better gear ratio.When you get the body off, take a pic of the other jackshaft sprocket.

[miniclimber]

my computer is not letting me post pics for some reason but the axle sprocket is 54 teeth the jackshaft out put is 11 teeth and the jackshaft input is 40 teeth

[T3beatz]

You can get pretty low on the front, I think down to 8T... My axle sprocket was a #41 60T if I'm not mistaken.

[miniclimber]

You can get pretty low on the front, I think down to 8T.

Are you taking about the one that drives the axle sprocket?

[T3beatz]

yep, the one that is on the Jack-shaft. I don't know how thick your jack-shaft is but most or 5/8" like these... http://www.*************/item/41-Sprocket-400901--1507

The one other thing I could suggest is getting a slightly bigger engine. One of the predators from Harbor Freight might work, they are like 6.5hp and they run pretty good.

[metalstudman1]

I'm betting this jeep has electric start(I saw a battery)- that's why I didn't suggest another engine to resolve the power issue and the stripped crankshaft threads issue.

[miniclimber]

I'm betting this jeep has electric start(I saw a battery)- that's why I didn't suggest another engine to resolve the power issue and the stripped crankshaft threads issue.

yea it has electric start. thats one reason i dont reaky want to get another engine. And the crank shaft wasnt stripped just the bolt so i found a grade 8 bolt and ran a tap through the hole to clean the threads out