Please help. I bought a used hammerhead 150 for my son who is battling a serious illness. The look on his face was awesome when I brought it home and he has been riding it off and on for about a week. Yesterday, the kart stopped shifting. It still runs, but will not shift into a higher gear. As you know, this is an automatic (CVT transmission), and was working fine until yesterday. I have to get this going again, as it is great for my sons spirit, and he is no down again. Here is what I have done so far:
1. Checked the gear box fluid, drained it and refilled - no help
2. We have taken of the cover assy. and the belt looks very good. (The pulleys are in the low gear position)
3. We removed the nut from the outer clutch Assy (it was way difficult) and inspected the outer clutch (seems ok?)
4. tried to remove the nut from the cooling fan on the other end of the belt (drive pulley?), but it is too tight and the whole thing turns (any ideas how to get it loose, and do I even need in that part?)
After reading about how a CVT transmission works, it seems that maybe one or both ? of the pulleys do not move in or out to allow for a change in gears?

I am looking for anyone who can help steer me in the right direction. Please do not tell me to take it to a dealer, the company does not answer my e-mails. I do have a friend who works on ATV's and is quite good, but we need to know where to look.

Any help and advice would be greatly appreciated.
Thank you!
Doug

 

you need to use air impact wrench when removing the nut for the variator, i like to use a 1/2" drive, while the cvt cover is off, start the engine and rev it and see if in deed the belt is not moving up and down on the variator and clutch, of couse right now sitting still it should be in low gear but should move up on the pullys as the engine increases rpm.

 

Thank you so much for responding. I had trouble getting my 1/2 Impact in to the nut, so I tried my 3/8 impact rachet, but to no avail. When I get home I will try the 1/2 Impact again. I will first jack the rear end up and see if the belt moves like you stated.
Again, thank you so much for taking the time to reply. I will post the results of this effort tonight.
Sincerely.
Doug

 

Ok, the belt is moving, but it is not moving up and down the pulleys when reved up. Looking at the drive pulley something looks a little fishy?: There appears to be a small wire in the groove (where the belt is seated now) near the right part of the pulley (as you are looking at it from the rear). It really kind of looks like part of a spring, but I do not see a spring represented in the parts diagram that I have. Also, the left (variator?) seems to have a small gap (I hope the picture shows), anyway should that be there?


I am sorry the pictures did not turn out weal well, if you can not see from these, I will try to get others with a better camera.
Thank you again for any and all help.
Doug

 

i'd replace the whole variator, clutch and belt. oregonvintage.com has the parts here the part numbers and prices, variator 164-46 price $69.00, kevlar belt buggy part # MRP 039 $60.00, clutch part # 164-45 price $60.00 for $200 you'd have a whole new transmission. to remove the variator nut spay some penetrating oil or wd 40 let it sit for an hour or so, use a 1/2 in impact wrench with an extension and a universal . the key here is to make sure you have a big enought air compressor. when reinstalling the nut use locktite and a 3/8 impact wrench. do not over torque.
here's a couple of more places for your parts, engine is a gy6 honda clone
miamimoto.com
indycycleranch.com
e-bay look under go kart
do a web search

 

Thank you again for your time, I will give it all a try.
By the way, could you tell by the pictures if the variator pulley looked bad?
Thanks again.
Doug

 

what happens is that the rollers inside the variator goes flat and will quit rolling, if you decide to just replace the rollers i would recommend using dr pully sliders instead, they work better and of couse will not flaten since they're already flat, you might even consdier changing the weight of the rollers or sliders now, 14grs is stock, for better low end performance use 10grs.

 

chineseatvmechanic is right on the money. It sounds like a roller problem. I'd also highly recommend getting sliders. I'd go with a 10gram slider, you'll get much better climbing ability. Check out buggynews.com for more info. Lots of people on there that have that same buggy. Good luck and I hope your son gets better.

 

Thank you both. After replacing the variator (The rollers were bad and the bushing came out of the variator) it worked great - except that I had forgotten that my friend had loosened the nut from the rear pulley, The nut cam loose, and broke the housing and buggered up the threads. I ran a new nut back on with locktight and it was working great. Until just a day or two later my son hit the rt front tire on a tree and now the right tire points outward about 3-4 inches and I cannot find the problem. I have checked the struts, strut brackets, tie rods, tie rod ends and I cannot find the problem for the life of me.
I hate to be a whiner, but my luck really seams to be sour still. He has yet to get a full weekend of riding. Right now, it is still sitting in the garage until I, or someone, can help me find the problem. Oh, the steering still seems to work and both wheels still spin freely and neither rim appears to be bent.
Thanks.
Doug

 

The area where the tie rod end mounts to the strut is very, very weak. It bends very easily, especially after hitting a tree! Take a closer look at that - you may need to bend that back. Most of the buggy owners reinforce that with some welding. Check to make sure your steering rack didn't move. Assuming you bend that little strut arm back into place, you should be able to adjust the toe in. We've (buggynews.com subscribers) have had quite a few run-ins with trees and it would be unusual that the steering rack got damaged, although it is possible. Keep us informed.