anderkart
Moderator
If your clutch rides on a Bronze Bushing, instead of a Needle Bearing:
You could shim your clutch outward a half inch or so by first stacking 3/4"-ID. X 1-1/4"-OD. Thrust Washers onto your engine's output shaft before installing the clutch and Key. They're super thin so you could use however many were needed to perfectly align the clutch to your sprocket.
Then after installing your clutch and key: You could effectively extend your output shaft with a stack of 5/16"-ID. X 3/4"-OD. Hardened Flat washers.
Use high quality washers like these: https://www.fastenal.com/products/details/302703-130481
They'll fit inside of your clutches bushing, helping to support the drive gear of your clutch because the outer portion of your clutches bushing will actually be riding on these washers... Be sure to stack enough of these washers to slightly extend (a 32th to 16th of an inch) out past the outer (drive-gear) edge of the clutch, You'll simply need to instal enough of these washers to shim far enough outward so the clutches drum still spins freely and doesn't bind up when you tighten the clutch retaining bolt into the end of the engine's output shaft.
Then to complete the installation you'd just need a 5/16"-24 bolt, A 5/16 lock washer & a 5/16" x 1" hardened flat washer to secure the clutch to your engine. Make sure you buy a high quality/hardened bolt that's long enough to thread into around 3/4" of the threads you'll find machined into the center of your engine's output shaft.
Then after you've got the clutch installed and all perfectly shimmed in place; you'll discover the engine turns over as you try to tighten the clutch retaining bolt... You can solve this problem by simply removing the engine's spark plug, and feeding a length of clean Rope down through the spark plug hole into the cylender when the piston is at the bottom. This will safely bind the piston and allow you to tighten (or remove) the clutch retaining bolt without the engine turning over.
Your final step would be to either remove, or tighten the Allen Head Grub screws that came with your your clutch, you won't really need them...
PS:
If you have an ACE hardware stores in your town, you'll probably discover they stock all of those specially washers, and the bolt you'll need for this job.
PS: It'll be especially Important to keep the Bushing in your clutch lubricated with 3 drops of oil every couple hours of riding, because your clutch bushing will probably wear out a bit faster, compared to a normal clutch installation... The only time this bushing has any wear at all is when the kart is idling and getting up to speed, so just try to keep that to a minimum for a longer clutch life...
PPS: bring your clutch along to the hardware store when you buy the washers, to make sure the ALL of the 5/16 x 3/4" flat washers were correctly machined to perfectly fit the inside your clutches bushing...
