93 timberwolf not starting

I have a 93 timberwolf that always started fine, after leaving it at a friends farm for the summer it won't start.  Starter clutch slips, after pulling it out and cleaning it up it starts ok for a while.  Is there a easy way to tell which part needs to be replaced?  The cost is to high to replace them all.  

by starter clutch do you mean the bendix?
if so:

if the starter spins but all you hear is the starter motor turning, then chances are the starter bendix is bad.
or if it does this and occasionally starts the engine then the bendix is going out.
but visibly inspect the flywheel make sure none of the teeth are broken or worn out.

but if the starter motor runs but doesn't engage everytime then you need a bendix.

if the starter motor doesn't turn or occasionally turns check the starter solenoid. as well check all of your battery connections, it could be a short that doesn't allow enough juice to the starter to make it work all of the time.  
Keep it RUBBER SIDE DOWN!!

I do mean starter clutch, there are a couple of idlers betueen the starter and the starter clutch assembly.  It has a three point clamping system to turn the crank shaft.  

Oooh like the chinese atvs, or some of the older honda's.

sounds like one of the clamps is worn.  
Keep it RUBBER SIDE DOWN!!