BuggyMasters.Com - An On Line Mini Buggy Forum and Go Kart Forum

Go Back   BuggyMasters.Com - An On Line Mini Buggy Forum and Go Kart Forum > Technical Discussions > 150cc GY6 and Under Engine Tech

150cc GY6 and Under Engine Tech GY6 and Smaller Technical Discussion Forum

 
 
Thread Tools
  #1  
Old 09-12-2010, 11:05 AM
supertoast92's Avatar
supertoast92 supertoast92 is offline
Contributor
 

Join Date: Feb 2010
Location: Rochester, NY
Posts: 103
Default CVT Problem? (again?)

My Helix seems to be producing a loud whining noise which depends on the speed I'm going (or the rpm of the engine, if in neutral). The faster I'm going (or higher the rpm if I rev it), it seems that the whine gets louder, and it I think it's coming from the CVT. Any ideas what it could be? Maybe the belt's caught on something? I'll take the cover off and inspect sometime today if I get the time.
  #2  
Old 09-12-2010, 06:02 PM
chuckorlando chuckorlando is offline
Contributor
 

Join Date: Apr 2010
Posts: 356
Default

Couls be a bearing
  #3  
Old 09-12-2010, 07:41 PM
ckau's Avatar
ckau ckau is offline
Heavy Contributor
 

Join Date: Dec 2009
Location: central North Carolina
Posts: 915
Default

I'll bet it's one if the gear shaft bearings in your internal transmission. I had the same whining noise in one of mine. It got louder until a bearing granades! the trans then locked up! I had no other damage except for the bearing it's self but the tranny wouldn't budge until I cleaned out and replaced the trashed bearing A rebuild kit with sets of bearing are avalible.
In the pic , it will be either # 5,6,7 or 8. Don't bother trying to figure which one, just replaced them all. If one is failing, the others are not far behind. No big deal, they will pop out. they are not pressed.
This is normaly due to poor lubrication, low oil level or poor quality lubricant. In my case, I drained the tranny and forgot to refill
Attached Images
File Type: jpg gy6_catalog_page_01_dxl8.jpg (72.6 KB, 13 views)
  #4  
Old 09-13-2010, 03:03 PM
supertoast92's Avatar
supertoast92 supertoast92 is offline
Contributor
 

Join Date: Feb 2010
Location: Rochester, NY
Posts: 103
Default

But would the transmission not be moving when not in gear, just the CVT? The same whine occurs when I'm in neutral and sitting, just revving the engine.
  #5  
Old 09-13-2010, 05:47 PM
ckau's Avatar
ckau ckau is offline
Heavy Contributor
 

Join Date: Dec 2009
Location: central North Carolina
Posts: 915
Default

Quote:
Originally Posted by supertoast92 View Post
But would the transmission not be moving when not in gear, just the CVT? The same whine occurs when I'm in neutral and sitting, just revving the engine.
Yes it does , the internal trans is still spinning. Your neutral point is in the forward/reverse box, not the trans. The output shaft from the internal trans spins whenever the clutch engages.
  #6  
Old 09-13-2010, 06:32 PM
olderthan's Avatar
olderthan olderthan is offline
Heavy Contributor
 

Join Date: Jan 2010
Location: dayton nev--lake tahoe,nv
Posts: 588
Default

i don't think the helix actually has neutral just a area in between but your tranmission will
still be turning replace bearings
__________________
olderthan
2008 tomberline punisher
1500 spring 12g sliders
30mm cv pumper carb
uni filter no rev cdi
polaris xlt snowmobile shocks for front
w/550 magnum springs & blaster fronts on rear
and another buggy built working on mods gk-13
white spring 17 gram sliders so far
  #7  
Old 09-14-2010, 08:56 PM
supertoast92's Avatar
supertoast92 supertoast92 is offline
Contributor
 

Join Date: Feb 2010
Location: Rochester, NY
Posts: 103
Default

The gear selector is a 3-position, F, N and R, N being in between of course. But then again I wouldn't know enough to be able to tell you if it's true neutral or not.
  #8  
Old 09-15-2010, 08:06 AM
bige's Avatar
bige bige is offline
Contributor
 

Join Date: Jul 2009
Location: prattville alabama
Posts: 370
Default

yes the helix does have a true neutral, pull the cvt cover and see if the fan is rubbing
  #9  
Old 09-18-2010, 08:00 AM
supertoast92's Avatar
supertoast92 supertoast92 is offline
Contributor
 

Join Date: Feb 2010
Location: Rochester, NY
Posts: 103
Default

Pulled it yesterday, the cover didn't seem to have any marks on it, nor did the variator fan or clutch bell. Funny thing is when I replaced the CVT the noise seemed to magically have stopped (or muted a bit). Maybe something is/was rubbing in there, but both nuts holding the clutch and variator were tight, so they weren't coming loose.
  #10  
Old 09-19-2010, 09:53 PM
SYCARMS's Avatar
SYCARMS SYCARMS is offline
Supporting Vendor
 

Join Date: Sep 2009
Location: Senatobia, Mississippi
Posts: 3,375
Default

Have you checked to see if you have fluid in the final drive? TOM
  #11  
Old 09-19-2010, 10:02 PM
supertoast92's Avatar
supertoast92 supertoast92 is offline
Contributor
 

Join Date: Feb 2010
Location: Rochester, NY
Posts: 103
Default

Final drive? How would I do that?
  #12  
Old 09-19-2010, 11:33 PM
SYCARMS's Avatar
SYCARMS SYCARMS is offline
Supporting Vendor
 

Join Date: Sep 2009
Location: Senatobia, Mississippi
Posts: 3,375
Default

On the back of engine you will have a drain plug on the underside and a fill plug on the left side of case. You will fill the unit just like a car rear end to the threads. If you go to American Sport Works web site you can download all the manuals, all you will need is your model number which I believe will be a 7150 but don't hold me to that. I would drain the factory fluids and replace with a high quality synthetic. TOM
  #13  
Old 09-22-2010, 09:15 PM
supertoast92's Avatar
supertoast92 supertoast92 is offline
Contributor
 

Join Date: Feb 2010
Location: Rochester, NY
Posts: 103
Default

Didn't get a chance yet to do so, but I want to note another possible symptom. It seems as if the go kart drags quite a bit when in motion. When I let off the gas, even on level terrain, it acts if I'm slightly braking. When in neutral, the kart moves freely. I can feel some drag, especially on pavement.
  #14  
Old 09-23-2010, 07:19 AM
SYCARMS's Avatar
SYCARMS SYCARMS is offline
Supporting Vendor
 

Join Date: Sep 2009
Location: Senatobia, Mississippi
Posts: 3,375
Default

Is your hand brake on, or adjusted to tight? Does the rear caliper hang , and do you have fluid in final drive. Best way to check is to put rear up on stands than inspect those 3 things. It might be a hung brake. Also check front brakes. TOM
  #15  
Old 10-08-2010, 07:21 PM
supertoast92's Avatar
supertoast92 supertoast92 is offline
Contributor
 

Join Date: Feb 2010
Location: Rochester, NY
Posts: 103
Default

Update: Today I finally made a trip to TS and bought some new 80/90 weight final gear oil, changed what was in the Helix. A lot came out when I drained it, so that wasn't the problem. At least I have fresh oil in there now.

I know for certain now that it's in the CVT, because there's a loud unusual sound coming from in the case when I put it in gear and slowly push it back and forth. Something's rubbing around the driven pulley, so I guess next thing to do is (once again) take that cover off. I took it off a few weeks ago, nothing looked like it was rubbing after a quick inspection.

Also for the brakes, they are definitely not hanging. Kart rolls easily on its own in neutral on flat ground. I'll probably run it on jack stands next time I take a look at the CVT.
  #16  
Old 10-11-2010, 10:28 AM
SYCARMS's Avatar
SYCARMS SYCARMS is offline
Supporting Vendor
 

Join Date: Sep 2009
Location: Senatobia, Mississippi
Posts: 3,375
Default

From what you describe it sounds as if it will be either in the gearbox or final drive. Did you notice any metal in the fluid drained? Tom
  #17  
Old 10-11-2010, 10:32 AM
supertoast92's Avatar
supertoast92 supertoast92 is offline
Contributor
 

Join Date: Feb 2010
Location: Rochester, NY
Posts: 103
Default

Nope, nothing was in the fluid. I think we have figured out that it's the bearing in the CVT case. I think it's starting to go. When the case is off and we push it back and forth in gear, the sound isn't there.
 


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 01:28 AM.


Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.