My last jetting question - 07 WR450

[Island Boy]

I am 95% there with my jetting. Finally... after much trial and error... no off idle bog, no sputtering, no backfiring. The bike runs strong, crisp and smooth through all gears UNTIL I am going faster than 50 mph. I am experiencing some sputtering at constant throttle and backfiring when i let off on the throttle. What factors would cause this?

Altitude: sea level

80-90F avg. Temp

GYTR fuel screw 1.5 turns out

R&D Power pump w/ ALJ set at 40

168 Main

45 Pilot

JD Red needle, clip in 4th position

DR D full race exhaust

All free mods done

Thanks

[Gary Murray]

incorrect jetting.

[KennyMc]

I am 95% there with my jetting. Finally... after much trial and error... no off idle bog, no sputtering, no backfiring. The bike runs strong, crisp and smooth through all gears UNTIL I am going faster than 50 mph. I am experiencing some sputtering at constant throttle and backfiring when i let off on the throttle. What factors would cause this?

Altitude: sea level

80-90F avg. Temp

GYTR fuel screw 1.5 turns out

R&D Power pump w/ ALJ set at 40

168 Main

45 Pilot

JD Red needle, clip in 4th position

DR D full race exhaust

All free mods done

Thanks

Check this out. No resolution but some suggestions.

https://www.thumpertalk.com/forum/showthread.php?t=636373&highlight=stutter

[123BigcoopDawg576]

I am 95% there with my jetting. Finally... after much trial and error... no off idle bog, no sputtering, no backfiring. The bike runs strong, crisp and smooth through all gears UNTIL I am going faster than 50 mph. I am experiencing some sputtering at constant throttle and backfiring when i let off on the throttle. What factors would cause this?

Altitude: sea level

80-90F avg. Temp

GYTR fuel screw 1.5 turns out

R&D Power pump w/ ALJ set at 40

168 Main

45 Pilot

JD Red needle, clip in 4th position

DR D full race exhaust

All free mods done

Thanks

when your doing 50mph i assume your only about 1/4 throttle and are in 5th gear right? two things....if it was me i would do a 48 pilot as 45 is stock and thats pretty lean and then i would check your throttle positioning sensor (TPS)...

[Island Boy]

incorrect jetting.

thanks smart arse.

[kevinwr450f]

Did you take off the AIS? That was causing backfire on decel for me. Removed it and have not heard a pop since.

[Island Boy]

Yes AIS removed. I will look into disconnecting the TPS and report back what i think.

[Island Boy]

I disconnected the TPS at the 3 pin connector under the tank and taped it up. Ran the bike and guess what... Problem Solved... I did not notice any loss in power either (mentioned in the manual and some TT members experienced this). Thanx for all the help.

[jams229]

I was going to tell you to fiddle with the TPS, but it appears you already have... I sure would like to know the other effects of disconnecting it.

I have heard you should keep it plugged in for off-road, but I cannot remember why. I ride about 95% off-road, but the 5% on-road can be annoying due to the "TPS Stutter" Please keep us posted.

Thanks.