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2016 Mud Pro 1000 Rough Idle

1108 Views 5 Replies 3 Participants Last post by  doorfx
Hello All,

I recently bought a "used" Mud Pro 1000 SE with 426 miles on it. When I went and looked at the machine the prrevious owner said that it's rough idle was probably because of "old gas".

When I start the machine it fires right up perfectly. After about 5-10 seconds once the idle lowers it starts to drop in RPM, and then die. If you rev the machine or drive it it runs perfectly.

I recently just changed the oil, and put fresh plugs in it. I also syphoned all of the old fuel, put it fresh 87, and added a bottle of amsoil quickshot.

No improvements. It's kind of annoying me as my 2009 550 H1 idles and drives like a dream. I checked all electrical connections and everything looks perfect. The machine is very clean and has hardly been ridden. Since I drained the old fuel I only road the machine around my house a few times. Maybe the old fuel hasn't been 100% used out of the tank?

Any help is appreciated. I tried searching on this forum and google and haven't found any better suggestions than what I already attempted doing.

Thanks in advance,

1 - 6 of 6 Posts
Check your TPS
Check your TPS
I purchased the TPS tool, took off the front plastics, got to the TPS, sensor reads 0.63 at idle (service manual says 0.58-0.62). I adjusted it to 0.59 and it’s doing the exact same thing.

Any other tips? This is driving me insane.
My initial thought is a gummed up fuel pump or fuel filter from the old gas just sitting in there. Check EFI make sure ur all good there.
So I spent a lot of time last night messing around with the machine. I replaced the fuel sock at the end of the pump, drained all the fuel out and cleaned out any sediment in the tank, put fresh gas in and some seafoam. Still the same thing. I ended up figuring out what the problem is, the ISC Valve sensor is shot. I ended up spraying brake cleaner all over the area of the throttle body and while directly hitting the ISC valve sensor, the machine would idle perfectly for a little bit and then go back to the way it was. I took the sensor off and cleaned it and reinstalled. It seems to idle better but not perfect. So I ordered a new sensor, and o-ring ($214 for the sensor alone) from country cat and it's arriving Friday. Looking forward to replacing it to hopefully have a smooth idling machine.
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Did you try the reset on the ISC?
1 - 6 of 6 Posts