04 WR450 Gray Wire

Can anyone tell me what circuit the gray wire that everyone is hinting for me to undo is in? Why is it there and what will undoing it do? I'm trying to get rid of the stutter at a constant throttle position. I've uncorked the exhaust and went one mj richer (165) stayed at Canadian stock setting pj#48 and to the 5th clip position on the needle. I rode in the foothills the other day @4000' altitude and 20c. I felt it was rich enough and was blown away as this was my first big ride on this amazing bike. Plug shows air/fuel mixture good (clean, light tan color). I'm totally happy with it except it's got that inherent trait of not holding steady rpm with steady throttle input. I found what I've been told is the gray wire in a connector under the fuel tank and under the frame just behind the rads. Can someone confirm that this is the one (its in a connector with six sockets/pins and its the only gray wire I could find). Also is this mod applicable to the 04. The tps disconnected helps a bit but doesnt eliminate the stutter. I'm going to try the acv mod too but don't think it should affect the rpm at steady throttle as it is sprung open until a large vaccuum is present.

go to offroad.com and look up the wr450 project bike. they have some good pictures. using the search feature will give you all the info on the results. i'm not sure this will help with the stutter, though. it's a dirt bike, not a road bike. yamaha was not looking to make this a smooth cruiser. disconnecting the tps has solved the issue for some but you give up some performance quality in the dirt.

Thanks for the lead to the 03 project bike. It confirmed that I had the correct wire and I cut it to advance my ignition timing curve to that of the YZF. I took it out for a quick trip at 3000-4000 rpm and it was alot more steady. Still a little bit of rpm hunting/wandering but much better. Then I disconnected the TPS again and it held very steady at one rpm. It seems the two together work to eliminate the problem. Awesome! I don't think I'll leave the TPS disconnected though because it seems that the throttle is more responsive with it connected.

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