Looking for Clutch advice (Noob)

[Lordofangmar]

Hey guys,

I have been meticulously scrounging and building a go kart from scratch for about a year now (on a highschoolers budget) and am running into a bit of a dilemma.

I am a bit rushy and got a good deal on a Max Torque 10T CC and 50T drive sprocket for my Unmarked Briggs Test Engine (I got it from school and it didn't have the identifier number, just the briggs logo. I think it's a 950, it has a 3/4" Crankshaft and looks similar in size, you can sort of see it in the photos below. I did not really know at the time that a 5:1 ratio has the probability of burning through my clutch rather quickly

In addition to the gear ratio, I am running 17" lawn tractor tires that I got for free.

I got my first powered motion yesterday, but it came with a very very hot clutch and a burning smell.

I was looking for advice from you guys as to whether or not this setup will cause me to quickly burn through my clutch? And if so, how should I proceed in fixing the system?

One of the ideas I had was to fabricate my own clutch with a belt and pully system and jackshaft, but the number crunching led me to the conclusion that this was not as cost effective as a chain and sprocket system.

The entire kart is self fabricated with the aid of my High School's Machine shop. I have access to a wide variety of tools to fix things up if need be.

 

[itsid]

that gear ratio will sort of work for a modded engine and 11" wheels (rear)

it's nowhere near decent for a unmodified engine with 17" wheels

you want to keep the wheels?

well then get a 88T rear axle sprocket and you might have a have chance of not instantly ruining your next clutch.
(the one you have is most likely already dead)

'sid

 

[Arkyhunter]

you need something to hold your steering wheel in place.And how about a pic of your axle bearing setup.

Vance

 

[Lordofangmar]

Arkyhunter,
I am aware. I need to buy some 5/8" shaft collars on my next visit to the hardware store. I am using a 3/4" live axle attacked via pillow blocks

Itsid,
I did a quick search, and I'm not finding many 88T sprockets I can adapt to my hub. Any other suggestions. I want to be safe and all, but I'm not exactly rolling in the dough, if you know what I mean

 

[itsid]

I think you could get away with about any sprocket above 78 to be honest...

or let's put it this way: the bigger your butt, the bigger your toothcount.
(yes for engines this small weight IS really important)

Or if all you can find is maybe a 60T sprocket, then get that one plus buy much smaller tires (11" if possible, 12" if necessary.. not bigger )

'sid

 

[landuse]

If you buy a TC, you "might" get away with 17" tyres. You will need a 60T sprocket though. IMO the 50 will still be too tall a gear ratio.

You could also look into making a jackshaft. This will allow you to use smaller sprockets to achieve a lower gear ratio

 

[Lordofangmar]

What about a manual clutch. Sure the pulleys may cost money but I would be potentially wearing thru belts rather than clutches.

Would that eliminate the need for a new axle sprocket potentially?

I could run 10 T 3/4 bore sprocket to my existing sprocket on a jackshaft, turning a pulley running like a 1:1.5 gear ratio from jackshaft to axle, with a spring activated idler pulley allowing me to have a foot operated clutch?

Could this work with my tires and engine?

 

[OzFab]

If you're prepared to go to that much trouble, a 15/10 jackshaft, which will give you a drive ratio of 7.5:1, would probably be cheaper & easier...

A 16/10 js will give you 8:1
A 17/10 js will give you 8.5:1