Chain getting tight

JanGaLanG

Member
Made a gear change at the track on Friday tightend up the motor chain had alittle slop in it just how I want it. When I got home the chain was alittle tight but when I spun the axle alittle it would loosen up so I was tight in one spot and loose in another. I haven't touched the kart since taking it off the track and put up in the garage. This morning I just came out here and this chain is so tight I can barely turn the axle. What am missing here guys?
 

Joe28

Member
Not sure, maybe heat expansion and contraction when cooled down. If not in a bind, I’m not sure. New chain or older?
 

sundog

Member
Take it all apart, clean everything, check for bent components with a dial indicator, put it back together. If it still pulsates you can set it on the tight spot, loosen the sprocket bolts and tap it lightly towards the engine shaft with a soft mallet. If that doesn't work you might have to file a little off of the inside diameter. Sometimes a stamped out sprocket will have a rough edge you can smooth out.
 

Bumpy

Member
We chased that problem for awhile. Disassembly, dial indicator
and changing multiple sprockets. Changing sprocket manufacturers
helped some but it ended up being an out of round issue with the sprocket hub.
 

Colt sr

Member
Check rear gear for warping also inspect your clutch thoroughly. We had one do that to find out drum was bent on clutch
 

MaxxT Out

Member
Check you rear Motor Mount Butterfly, if it is being tightened down where the Nerf Bar spud is welded at Chassis, it could bind on the weld when tightening. Rear butterfly on outside motor rail...
 

JanGaLanG

Member
Thanks for all the replys guys. I just came in from checking all of your guys suggestions and could not find a clear answer to the problem. I checked the sprocket half's and they were fine. Checked the sprocket hub for roundness and it was fine. Chain has 3 night on it after inspecting it had a few binds in it. Clutch drum checks out. Axle is not bent. Hub to drum was straight. A few chain links were alittle tight and had gunk build up so that couldnt help. I'm alittle baffled as to how it went from slop before race to tight when I got home to can't turn the axle a night later. Heat Expansion and contraction of the chain is the only thing I can wrap my head around.
 

mike97760

Site Supporter
The holes in the gears arent often a tight fit over the hub studs and can allow a gap between the gear halves when tightened. We see this a lot. Have you tried other gear sets? Other drivers? I dont know what gears you run but 11 tooth drivers never seem to spin as well as the bigger ones. Another common problem is using the wrong thickness snap ring to retain the driver, allows the driver to cock a little in the hub.
 

sundog

Member
If it had slack before then was tight after, your motor mount probably moved forward. If you have a screw on the chassis to keep the mount from moving back, you have to leave a paper thin gap. If the screw pushes on the mount it will move it forward during a race.
 
Had a similar problem. The set screws on the bearings were loose on the axle. The rear axle wandered a half inch to the right and left. Chain went from tight to loose and back to tight.
 

JanGaLanG

Member
If it had slack before then was tight after, your motor mount probably moved forward. If you have a screw on the chassis to keep the mount from moving back, you have to leave a paper thin gap. If the screw pushes on the mount it will move it forward during a race.
Front butterfly on the motor mount is cracked on the wing. And bearing are shot with no set screws. Axle was just turning inside the bearings.
 
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