First kart build, lots of trial and error!

[mysteryboy28]

yeah, i think i'll be biting the bullet and making a jackshaft - which will allow me to move the main axle sprocket closer to the wheel.

I'd really love to get this kart done! Not going to spend more than $200 on a torque converter though. my first kart was a Manco Dingo 2-seater with a nearly new 11hp clone motor with electric start, Comet 40, had a differential on the axle, headlight, and hauled a$$. i only paid $325 for it!!!

 

[mysteryboy28]

ok, here's another attempt at trying to see if possibly it isn't my Comet 30 clutch that's causing the problem with my belts dying almost instantly...

possible alignment problem? sharp edges on the inside surface of the clutches? i've sanded down any roughness i could find since the last belt toasted. afraid to buy a new belt and try it (at $16 a pop). lol.

seems the comet 40/44/500 series all use belts that aren't much more durable than the comet 30 series. GTC TC2 torque converters are rated for 8-13hp, and yet they're advertised as a replacement for the comet 30 - which only supports up to 8hp. it appears they both use the same belt! WTF!?!

so i'm really starting to think my comet 30 ISN'T the REASON my belts are getting ruined within an hour of installation.

somebody has to have a suggestion that isn't going to cost me $200-350. cuz if it does - then this project is done, and i've just wasted a lot of time and money. yes, i'm frustrated.

 

[mysteryboy28]

closer inspection of my most recently ruined belt shows that it has been chewed up on the slanted side. there's an obvious groove that has been carved into the belt. nothing obvious on the driven or driver clutch to indicate any sharp edges that might have cut into the belt. the flat side of the belt is where most of the "string" from the belt was fraying/separating from the belt. blah.

 

[mysteryboy28]

best guess is that once the belt was chewed into and the string started fraying - that's when the belt started stretching. it sits on the comet 30 obviously looser now. i can slip the belt over the driven clutch without any effort now. before i had to pry the driven pully apart a bit to slip the belt on. not any more!

let's focus on what might be chewing the belt up...

 

[r97]

ok, here's another attempt at trying to see if possibly it isn't my Comet 30 clutch that's causing the problem with my belts dying almost instantly...

possible alignment problem? sharp edges on the inside surface of the clutches? i've sanded down any roughness i could find since the last belt toasted. afraid to buy a new belt and try it (at $16 a pop). lol.

seems the comet 40/44/500 series all use belts that aren't much more durable than the comet 30 series. GTC TC2 torque converters are rated for 8-13hp, and yet they're advertised as a replacement for the comet 30 - which only supports up to 8hp. it appears they both use the same belt! WTF!?!

so i'm really starting to think my comet 30 ISN'T the REASON my belts are getting ruined within an hour of installation.

somebody has to have a suggestion that isn't going to cost me $200-350. cuz if it does - then this project is done, and i've just wasted a lot of time and money. yes, i'm frustrated.

Alignment isn't a big issue, as long as its close. (I think some setups might actually be setup specifically to have some amount of misalignment). Post a picture of the sheaves if you want, but as long as they aren't like sandpaper I don't think much will happen. One thing I would check for is that you have the correct belt, and that it is installed correctly.

The GTC clutches being rated at 13hp is complete BS.

As I mentioned before your gear ratio may be contributing to the short life of your belts, that said I still think your main problem is a wimpy clutch.

If I were you I would try to sell the comet 30 and but that money towards the 40/44/500 series clutch. Doing that you could get down towards $200.

 

[mysteryboy28]

thanks, i just don't have the funds for a new clutch. i'd like to exaust all other possibilities as to the source of the problem.

i'm hitting both the driver and driven clutches with a brush grinder today to smooth the heck out of them and remove any unseen abrasive surfaces. i did NOT clean them up after the first belt burned up before installing the new belt. was probably melted rubber on the surface that contributed to friction, along with some rust from the age of the clutch.

also grinding off old paint on the frame/roll-cage and smoothing out my welds - in preparation for painting. thought i was going to go with bright rustoleum green (tested it, wasn't as bright as i thought it would be) - but at $5 a can - i may opt for walmart brand something or other. maybe settle for black? hmmm...

 

[r97]

Well the best thing you can do to get your clutch to work as well as it can with this setup is to gear lower.

 

[Simon Thomas]

I like the look of your build.

 

[mysteryboy28]

I'd gear lower, but I can't remove the axle. The sprocket isn't the split type, which would have been nice. Honestly though, I think my gear ratio is fine. I have good hill-climbing ability, and my top speed is reasonable (maybe 30-ish mph?). I don't want to sacrifice either, seems I have a good balance.

Looking closer at my belt, it really looks like it got carved up pretty good. So I'm going to take a chance and try another one - after cleaning the heck out of the clutch.

Bought 7 cans of black paint at Home Depot for 97 cents a can. Just waiting for a warm day and we'll get 'er done! Got about 8 inches of snow last night. Blah!

 

[mysteryboy28]

made a jackshaft, washed the kart down and started painting it. still need to carve out notches on the jackshaft rod for the 3/16" keys, although the sprockets i'm going to use also have the little threaded nubbies i could just drill a hole in the rod to accomodate instead. one sprocket on the jackshaft is larger than the other, so i might gear it for more torque and less speed to help the Comet 30 with the excess of horsepower. lol.

also lowered the front suspension a bit, which raised the front end for better ground clearance. i had noticed that when my almost 300 lb nephew rode the kart the front end only had a couple of inches of clearance - turning the kart into a grass catcher, and making big bumps hard to coast over. i also firmed up the shocks by compressing the spings a few notches. the damping on my shocks sucks, they move in slow motion. blah. will have to settle for now untill i can fit better shocks into the budget. maybe they'll soften/quicken up after i break the kart in some more. they do seem a little more responsive since i compressed the springs.

 

[Doc Sprocket]

still need to carve out notches on the jackshaft rod for the 3/16" keys,

Keyways.

although the sprockets i'm going to use also have the little threaded nubbies i could just drill a hole in the rod to accomodate instead.

Setscrews. And don't rely on setscrews to transmit power. They won't. They are there simply to positively locate the sprockets on the shaft. All that will happen is they will fail, mangling the shaft in the process. Go with your first instinct, and cut in those keyways.

 

[mysteryboy28]

will do! thanks... i sometimes forget that using "best guess" terminology can upset the experts. lol. i'm a computer refurbisher/repair tech, so when i hear people call their computer towers "modems", or they say they "downloaded" a program from a CD into their computer rather than INSTALLED - i always end up correcting them. lol.

 

[Fast Eddie]

Here's your solution (if you have the correct shaft size). Found these on OMB forum. Several members have bought sets and are happy.

http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&vxp=mtr&item=180761091447

It's a Comet Duster clutch setup. Much beefier than your 30 series. This guy has 50 pairs of NOS driver/drivens for $55/pair!

Link is for auction that ended, but just contact the seller directly.

 

[mysteryboy28]

thanks for the suggestion! both the driver and driven clutches in the pairs he's selling are 1" bore. the jackshaft i JUST fabbed is 5/8". i emailed the guy to see if he had a solution. otherwise i'll have to make a whole new jackshaft, and replace 2 sprockets.

 

[Fast Eddie]

...otherwise i'll have to make a whole new jackshaft, and replace 2 sprockets.

Still alot cheaper. New retail for the Duster setup is over $300.

 

[r97]

It wouldn't hurt to upgrade the js a little bit anyway, 13hp on a 5/8" shaft is ok, but not ideal IMO. Otherwise, a simple adapter with a 5/8" keyed bore and a 1" keyed OD would work great and be relatively inexpensive.

 

[Doc Sprocket]

i sometimes forget that using "best guess" terminology can upset the experts. lol. i'm a computer refurbisher/repair tech, so when i hear people call their computer towers "modems", or they say they "downloaded" a program from a CD into their computer rather than INSTALLED - i always end up correcting them. lol.

Sorry- I hope you didn't take offence, I'm quite used to correcting language. My two young sons (obviously) are still learning, and I have a non-mechanically inclined friend that is constantly screwing terms up. The real issue is that half the time I have no bloody idea what he's talking about, and we have actually had arguments in the past regarding something- only to find out we were talking about the same dang thing after all!

...Doesn't help that I was an English major in High School...

 

[mysteryboy28]

Got the kart painted (aside from the underside... low priority. lol). Slapped most of the parts back together. Figured it was time for a photo shoot. Sorry for the dark pics, better ones will be coming soon!

Also decided that i'll be painting the rims red to match the shocks - or maybe silver?. I think the black and red go well together.

 

[mysteryboy28]

Looking into the Comet Duster (model 94c) it appears that the engagement RPM is about 4600 RPMs. Considering the fact that my engine's top RPM is 3600...

 

[Fast Eddie]

Looking into the Comet Duster (model 94c) it appears that the engagement RPM is about 4600 RPMs. Considering the fact that my engine's top RPM is 3600...

You can vary the engagement RPM from 1600 to 4600 on the Duster with spring changes.