Have a vertical Escape with SLP single pipe and can, ATAAC, V Force 3 Reeds, High flow air box, Cheater Heads, SLP Clutch Kit, Boost Bottle, Flow Rites.

Sled runs great up to 1/4 throttle and after 1/2 throttle. DET light starts flashing and the egt's max out at high temp.

Tried changing the needle position all the way up, moved tps both directions, adjusted fuel screw at all settings possible, changed back to stock, no matter what I try, nothing changes.

Any ideas?????

Thanks for any help I can get.

You mean when you hold it at steady throttle between 1/4 and 1/2, it spikes the egt's? Are you running at low altitude, or in the mountains? What heads do you have? You may need to get a 5/20 shim kit to fine tune the needles, or go to the XC ones. I don't have the chart, but maybe they are richer in the throttle position you need.

I am running the SLP Cheater Heads for High Altitude. I have tried the sled at 8000 feet and 550 feet with factory settings and setting suggested by SLP.

I adjusted the TPS setting to 4.0 volts. I also tried it at about every position possible just to see if it made a difference. It did not.

Saturday I did some testing and changed the sled to lowest possible altitude for the ATAAC, jetted the mains to 510, put needles at highest possible position (clip in lowest slot), turned TPS all the way clockwise, which retards the timing, and reclutched.

It ran much better but still the DET started blinking and when you hold the throttle at just under half throttle, the egt's rise off the guage.

No matter what I do with jetting, needles and tps setting, the sled runs absolutely perfect except for half throttle det and high temp on the egt's.

By the way, I did try the 5/20 shims. :frech32:

the cheater heads are really high compression heads for above +8000', try puting some high octain fuel in the tank and see if it still dets? cam2 or av gas 100 low lead ,I like vp's fuel best. Most guys are running VP's MR1 in there race bikes.

If you run the high altitude heads below the altitude they are specified for, without adding a race fuel mix, you will have lean spots no matter what you do.