TAV-2 belt and driven pulley buttons burned up!!

[Torquerolljoe]

As the title says, my kids were riding there kart today when it i smelled burning rubber as they passed by me. I called them in and noticed the dust cover had smoke billowing out from it. I told them we had to call it a day and that I would have to look into the problem. Anyway, I got the kart home and let it cool down. Then I disassembled the TC and checked for problems. The belt and driven pulley cam buttons were melted. It will need all 6 buttons and a belt. I completely disassembled the TAV2 and inspected and could not find any areas of concern other than rubber from the belts on the sheive pulley's. Has anybody else had this type of problem? Any input would be appreciated.

BTW, the TAV has a 10t 41pitch gear, the kart has a 60t gear on a live axle with 18x9.50-8 tires in the rear. It weighs about 150lb without kids. With kids, it weighs about 300lbs. It has a new clone 6.5 slightly modded with a stage 1 kit from AGK and billet rod from ARC. I did a valve job and ported the head. It has great power and the kids love it. I myself am an automotive master technician of 18 years. I knew to check for alignment, wear, blueing, etc... in the TAV. Is it possible that "gunning" the throttle caused it to slip excessively and caused it to overheat the belt? BTW, it is a new TAV unit I have had for about 6 months. If you need any other info, I can easily get it for you. Thanks in advance.

Joseph

 

[freakboy]

im sure its from not really cleaning and lubing it properly after every run.

 

[residentg]

check the driven pulley bearings. I have never worked on a TAV2 but twice I have had jackshaft bearings fail with the same results as you have described. As FB says above, you need to clean the pullies, here is a link for that:

http://www.gokartsupply.com/asymapp.htm

here is a link to the comet manual:

http://www.gopowersports.com/comet/Tav30.pdf

 

[Torquerolljoe]

I will definitely be looking into keeping it clean and lubed. I may have failed there. I will be ordering 2 belts and extra driven cam buttons today. Hopefully after cleaning and rebuilding it, I won't have any other problems with it. It was a bummer to see my kids fun end so soon. Lesson learned. If I get anything else figured out, I will let you all know.

Joseph

 

[nerfo]

This is actually an area of concern of mine as well. I'm putting a lot of thought (perhaps too much) into my final drive ratio. I want to use 18" tires as well and was also kicking around the 6:1 final drive ratio. Your 10 tooth driver and 60 tooth driven... mine was just going to be 12 tooth driver and 72 tooth driven... but I'm wondering if between your engine mods and tire size, that gear ratio is just too high? Now that Comet's doors have shut, I'm a little more concerned about all this.

 

[Jdominique]

Mine has done this once as well. I finally drudged it out of my son that he was pulling his buddy on a sled. I assumed it was just the extra weight that fried it.

 

[1992suburban]

make sure the kart is not binding anywhere. and that much weight with that tall of a tire probably did her in..

I would change the final ratio.. with that size tire I would shoot for 7.5:1 ratio carrying that much weight


you realize with your current setup the kart is capable of 50mph with a slightly modded motor..

 

[Kenny_McCormic]

There are production karts geared like that with weaker CVT systems. Something isn't set up right.

 

[Rickracer]

There are production karts geared like that with weaker CVT systems. Something isn't set up right.

They probably don't have enough power to "overpower" the clutch though. I think a lower gear ratio would be a good idea. I would gear it for about 30~35 mph, taking the tire size into consideration.

 

[nerfo]

I kind of want to agree with Rickracer on this one. A 6:1 ratio might be fine in most applications, but if it's even a slightly heavier kart with two people on it... 18 inch tires are probably going to be too tall. I mean, with the gov. removed on a little 6.5 horse clone engine, you could be pushing 50 mph or better on flat pavement. Asuza makes sprockets, split or un-split, with tooth counts that go into the hundreds (for #35 chain, 41 chain, probably into the 80's). Keep in mind... a TAV doesn't see tire size, gear ratio, or kart and rider weight... all it sees is LOAD. If the gear ratio is too high... excessive load. Tires too tall, excessive load. Too heavy a kart... again, it's just excessive load. By swapping out the axle sprocket with one of a higher tooth count, (maybe 72 or 80) you'll reduce your top speed, but it'll get going quicker and the clutch will probably thank you with significantly longer service!