Intermittent Ratcheting

[ouhockeyplayer]

I took my 2008 FX Nytro out for the first ride around the yard today and noticed that my track was ratcheting under hard acceleration. Tried messing with the adjusters to make it tighter but the track was already pretty tight. Finally tried adjusting it to Yamaha spec but didn't have anything to put an exact amount of 22 pounds of pressure on the track to get approximately an inch gap between the track and sliders (seems awfully tight). After making this adjustment it seemed to help but I still got a ratcheting feeling here or there under hard acceleration. I could go from a dead stop and hammer the throttle and it wouldn't do it but a few minutes later (in a different spot in the yard) under hard acceleration I would get a ratcheting feeling. Now the sled did not do this when I put it away but over the summer but I did change the GYTR front shocks out for Exit aftermarket shocks. Could front pre-load or shock settings have anything to do with it? The rear limiter straps are in the stock position and rear suspension was rebuilt by Hygear last winter. I'm wondering if varying traction and snow conditions had a big factor in it as the sled was trenching down to the grass pretty easily under hard acceleration possibly causing it to go from spinning to biting quickly. Snow was about 6 - 8 inches or so. Any help is greatly appreciated.

 

[ouhockeyplayer]

Oh and sled has roughly 3,300 miles on it as well.

 

[ouhockeyplayer]

Doing a little more research today and thinking switching to an extrovert driver system is the best way to go to get this under control. I'm thinking this spring/summer I'll put in a new track and change the drivers. Anyone running the Schmidt Bros setup http://www.schmidtbrosmotorsports.com/yamaha-anti-ratchet-drive-wheels/

 

[Big_Phil]

How are the clips on your track? Any left or are they all worn off? It shouldn't ratchet. The extroverts you will lose some top speed, and are probably unnecessary at stockish power levels. My backup stock nytro can wheelie all day with the stock drivers. Hooks like an animal and never ratchets

 

[1nc 2000]

How's the driveshaft bearing on the left side? Could be shot letting the driveshaft move around.

 

[ouhockeyplayer]

Clips on the track seem fine. How do you go about checking the drive shaft bearing?

 

[jimbur]

You might be able to see with a light from underneath . Otherwise pull speedo sensor and bearing cover underneath the secondary clutch.

 

[ouhockeyplayer]

Would you be able to tell by checking the secondary for side to side or up and down movement by trying to move it by hand?

 

[ouhockeyplayer]

Never mind. Realized that's separate from where the driveshaft bearing is. I'll have to check it Friday when I'm home. Looks like it's a pretty quick fix to replace that side of its needed. Will I be able to tell the bearing is bad due to the drive shaft looking not centered as it enters the tunnel?

 

[hibshman25]

I'd pop the seal out of the bearing with small flat blade screwdriver and inspect. If it's all rusty it should be replaced. If it is really bad ball bearings may even be missing.

 

[ouhockeyplayer]

I ordered a new drive shaft bearing since they aren't very expensive at all. Might as well replace as preventative maintenance since just checking it is pretty much half the steps to replace it. At 3,300 miles it would be good peace of mind so I don't miss out on our short season with a failure. I also found a fish scale at a sporting goods store that I can use to pull down on the track with 22 pounds of force to more accurately set the track tension.

What should I look for when determining if the drive cogs are worn and possibly slipping a little? Are the edges supposed to be mostly square when new and get rounded over time causing slippage?

 

[hibshman25]

I rarely see drive cogs that are worn bad enough to cause the slippage. I have seen the drive lugs on track get chewed up from broken suspension parts, ice, rocks ect.

A broken front pivot arm in the rear skid could also result in racheting

 

[ouhockeyplayer]

Thanks. I just had the skid out before I put the sled away to refresh the rear shocks and didn't notice anything broken or out of sorts.

 

[Dr. FeeLGooD]

If it is rusty it can be a lot of fun to take apart. Mine was a real treat.

 

[radianguy]

Not chain case making the noise is it? I'd check chain tension to be safe.