M7 WOT stumble

I just bought this 05 m7 162 from a buddy of mine. When he bought it, it had a Speed Werx 925 in it. He fought with getting it to run correctly for a couple years, then it broke a skirt on one of the jugs. So he put a stock engine it.

Anyhow, when pulling a hill at wide open throttle, it will stumble, like it is running out of gas or the ignition is retarding or something like that. If I let off and get back into the throttle it will slowly come back around.

It has the BDX power valve delete, Boyeson reeds, and a BDX intake. Other than that the engine is stock. I do have an Attitude fuel tuner for it, but have been told that I don't need it for this set-up

I have read some that guys were having problems with the taillight wiring shorting and causing the computer to freak out and cut some timing. I have not had a chance to check this yet.

Any hints of things I should check?

BDX delete

The electronics for the BDX power valve delete is installed. The tuner is not currently installed.

I need to check the taillight wiring I guess.

Power Valve delete...

I really can't tell you one way or another if I like it or not. I never rode it with the power valves...I do like the fact that I don't have to deal with them if they decide to fail or stick. It runs pretty good, I am pretty happy with it. The first ride out, it was kinda doggy off the line....but the clutching was way off. We put lighter weights and the correct spring and it works good now.

I have been busy and have not had a chance to check the wiring....after blowing snow today, I rode it home and it reminded me of my Indys when the TSS would die.....it would act up when I played with the throttle.

So, tether...and disable the TSS? I am thinking that I want to move the kill switch anyhow, I hate it when I bump it in some technical halfway sketchy manuever......I have an Aluminum throttle block.....I believe it is pulling 40mm carbs....so would the ratio be correct for the throttle bodies?

Fixed

So the problem was the TSS....all of my Polaris' have done this in the past too. So I removed the kill switch and TSS from the throttle block, installed a momentary kill switch from a Kawasaki and a tether to add back the safety that the TSS tried to provide. The new kill switch would not fit where the stocker was, but I tried to figure it out. Any how, where it sits now it is just below the level of the rubber grommet deal which will protect it from being bumped on accident. The install isn't super clean, but it will work. I also removed the thumb warmer as the switch was busted off and I never use it. I made a lil aluminum plug to cover the hole to keep the snow out.