800 HO high idle

[Absledder]

Middle of a slow and easy ditch ride I stopped to take a break and when I went to restart the sled it idled really high (4000) for 30 seconds then died. Pulled and pulled and after about 45 minutes of cool down time it restarted. It seems to start better if I wait a long time between pulls?! Now I can get it running but it still idles high to the point of creeping without touching the throttle. I just don't understand how this problem came out of nowhere?

 

[Merc63]

Check the throttle linkage and sensors.

 

[Mantis]

Check y pipe bolts, carb boots and crank seals...could be drawing in air/lean condition.

 

[Absledder]

My first thought was that it could be getting lean but I don't see how that would happen in a couple minutes of riding? It was fine when I left my house and half an hour later it all of a sudden appeared? Hopefully it's just an iced up sensor or something, I have it thawing out in a friends garage right now so I'll see if I can find anything or if it thawing out magically fixed itself.

 

[ralphsmotorsports]

Sounds like a frozen throttle, it can be the cable itself orice build up at throttle body. There is a safety switch in your throttlecontrol that will kill spark when it senses a frozen throttle cable- but won'talways know a frozen throttle body, which would give you the very high idle.

 

[Absledder]

So I started it up after thawing out in the garage overnight and it was idling right around 2200-2400 which I think is where its supposed to be. I assumed that the problem was something freezing and that it had been solved so I took it for a quick rip and the problem came back. I got it back to the garage and I think there might be a crack at the flange weld on the PTO side of the y pipe. Its got some oily residue there that isn't anywhere else on the pipe but its currently way too hot to pull the pipe off and take a look at it. Does it make sense that a crack would cause the high idle? It only happens once the engine is hot, it idles fine when its first started. Would a crack like that cause a lean condition higher in the rpm range or would the pressure in the exhaust be enough to prevent drawing air in? I'm just hoping I didn't do any damage by riding it.

 

[Modman]

So I started it up after thawing out in the garage overnight and it was idling right around 2200-2400 which I think is where its supposed to be. I assumed that the problem was something freezing and that it had been solved so I took it for a quick rip and the problem came back. I got it back to the garage and I think there might be a crack at the flange weld on the PTO side of the y pipe. Its got some oily residue there that isn't anywhere else on the pipe but its currently way too hot to pull the pipe off and take a look at it. Does it make sense that a crack would cause the high idle? It only happens once the engine is hot, it idles fine when its first started. Would a crack like that cause a lean condition higher in the rpm range or would the pressure in the exhaust be enough to prevent drawing air in? I'm just hoping I didn't do any damage by riding it.

Probably not from the pipe, but maybe if you have any air leak. You got the pipe off anyway due to the crack, pull the plugs and check the colour, if they are good then probably not much risk of any issue. I would spray some ether around the intakes and see if it crops up, could be there is a leak in the boot or something. How many miles on the sled? I would also check compression.

 

[Absledder]

After I pulled the expansion chamber and the heat shield below it I was able to see that one of the clamps on the rubber boots has slipped. I wasn't able to take the y pipe off cause the extension I need seems to have gone missing but I'll let you guys know if I find anything. There just about 4000 miles and the top end was redone around 1800 because the engine sucked a reed in.

 

[Absledder]

Anyone know the torque specs for the y pipe bolts? And are the gaskets reusable or should I just go get some new ones and some high temp silicone while I'm at it?

 

[JONSHOW]

Anyone know the torque specs for the y pipe bolts...

Tada...

countrycat.com/ccstore/kbase/snow/2014/ZR_XF_M-2-Stroke.pdf

 

[JONSHOW]

Tada...

...page 75

 

[mountianguy]

hi temp silicone is the gasket from the factory

 

[Absledder]

Thanks for the help guys. I tightened up the loose clamp on the boot and put it back together. It was fine until I tried to lower my handlebars (adjustable riser) and then started to rev up right away. I took a closer look at it and it looks like its rubbing/pinched between the steering post support frame and the gas tank. Are all M series cables routed like this? or is it maybe something the previous owner did? Its a pretty tight spot and seems like a failure waiting to happen.