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 #10892  by Cfuzzkennedy
 Mon Sep 04, 2017 9:47 pm
2017 Hammerhead GTS 150

Uni intake
Carb and Jets
Header and Muffler
Adjustable CDI, Coil and Spark plug

Things were fine for a while, like 100 plus hours. Friday I was following a buddie through our trails and after about 30 minutes the gokart lost some of its go go juice, she was sluggish with no top end. Figured it might just be a carb adjustment so I headed in and attempted to get her back to speed. Nothing worked and I started suspecting Variortor issues. Luckily, I had ordered a new variortor, weights, belts, clutch and clutch bell and they had arrived Friday while I was at the property.

I returned back to the property this morning with all the new goodies in hand. This is a Dr. Pully upgrade kit with 11gr slide weights. So after about an hour I now have new upgrades and she is ready for a test run. Well, I was totally disappointed. Still sluggish on the top end, like there isn't one and no bottom at all.

So I take her back down and check everything. I start her up while on a jack and watch the variator and clutch work flawlessly. Motor is ideling smoothly and sounds great through all RPM's.

Changed the coil... same
Change the CDI...same
Pull carb and check jets, perfect
Retune carb... same
Bypass fuel filter... same
Test, test, test.... same! ???

Here is where my test ended, I pulled up to a tree and while in gear I floored it, clutch is slipping and wheels not spinning. Ok maybe the new clutch has oil on it or something. While backing into the shop I notice reverse feel stout. So I drove to the tree again and back up to it this time. While still in reverse I floor it and clutch is fully engaged and tires and digging into the ground? Uhhhh. So I try forward again, clutch spinning, tires not.

Back in shop;
Clean clutch bell and inspect pads
Inspect slider weights for bad installation.

Still the same!

Change pillow springs to lighter springs.

Still the same! Gah!

Brought her to a small levee about a 20*-25* incline.
At the base of the hill in forward, will not climb, clutch slipping, tires not.
Same place in reverse, up the hill like a bat out of hell, clutch fully engaged.

I have a fully stock kart as well. Went and got it and up the hill both ways without a problem.

I fell like the clutch isn't grabbing as much as it probably should, but it works perfect in reverse which make absolutely zero sense to me. And everything works perfect on the jack.

Top end did get better eventually, but there is just no get up and go in forward, backwards is a beast.
 #10895  by tkeagle
 Tue Sep 05, 2017 11:15 am
Not 100% sure. But reverse is geared different. Much lower. At least my external one is. Feel like going to brake something, if don't go easy with it.
(To me) sounds like a power loss issue. From what you all checked, don't see how can be a clutch issue at this point. Other then, did you check clutch pads and inside bell? I bought a (high performances) clutch kit. Noticed was not running like should. Put stock one back on. Ran great.
Looked at the HP one, and noticed where they drilled cooling holes for bell. Made a high spot in the bell, and could tell the clutch pads was not in contact with bell even 10% of what should be.
Power loss? Have you check for any air leaks behind the carb? Seems that issue creeps up the gy6.
Spark plug check?
Put a different plug in? They can get cracked, but never see it. Happened to me. Was about going crazy on what was going on. Changed plug. Fixed. 2weeks my life never get back again. :).
Can u do a compression test?
 #10897  by Cfuzzkennedy
 Tue Sep 05, 2017 7:05 pm
It's is a HP clutch and Bell and it's new.

I feel like it could be a power loss also. I'm heading back this weekend and will try whatever suggestions come my way. I can do a compression test, but unless I k ow what it's supposed to be, it won't matter. I have changes spark plugs.
 #10926  by Travis @ Buggy Depot
 Sat Sep 09, 2017 12:20 pm
The initial problem is very unlikely to have been related to the clutch or variator. But the problems you're experiencing after the new CVT parts install, (the big difference between power in forward versus reverse) usually indicates that a roller weight is turned sideways in the variator.

More info: Reverse is geared down 3:1. If a roller weight is turned sideways, it will be like starting your car in 3rd gear. No power, and destructive slippage of the clutch. You don't see this happen in reverse (it seems normal) due to the 3 to 1 gear reduction that isn't present in forward.

Back to the original power problem: What is the condition of your air filter / intake tract/ and intake manifold?
 #10934  by PGH
 Sun Sep 10, 2017 1:42 am
Make sure you are orienting the slider weights according to the supplied diagram and you are holding the variator together so they do not twist or slip out of place during assembly. This sounds like a typical weight out of place issue.
 #10947  by Cfuzzkennedy
 Tue Sep 12, 2017 8:27 am
So I went through everything and all was right. I started swapping out new parts with stock parts and finally figured it out. Once I swapped the carb, all was good. Something went wrong in the new carb and I can't find it.

It happened while I was driving, sudden loss of power. Still had some go to it, slow start and top end would get to about 75% of what it should be.

I'm at a loss. Why would it all of the sudden not work? Jets are clear, everything is clean...