Vortex tuning box jetting help



I have recently bought a WR450 after fixing the water seals and the impeller as it snapped, and starter damper as its a 2003, i finally got a chance to go out onit i cleaned the carb out aswell.

My mods are....

De snorkled air box

Throttle stop off

Leo vinici exhaust

Vortex tuning box


As im sitting at 30mph holding the throttle the bike feels like its coughing or jerking, at full revs it seems ok just the holding the 30mph which it hates. Also when i let off the throttle it back fires like mad, i have checked for exhaust leaks and everything seems fine.


The main jet i noticed is 160 from reading i have now purchased a 168 main jet, and a 48 pilot jet. Does this sound about correct?


Also on the bottle of the carb there is a red turnable mixture screw im guessing, im going two turn that full turns out


Chee.rs for the help



Make sure your pilot jet is clean or new.

Most people experience an on and off surge on the road. Try setting the Vortex ignition to the torque setting.

My 08 still surged with a Vortex so I replaced it with a Dynatec ignition.

How do you post your own topics

How do you post your own topics

Start new topic. Box to the right.

im going to also remove the tps, and replace both jets just incase

Ok little update. Put a 168 mj in and a 48 pilot screw. Unplugged the tps as I'm using it on the road.

The bike idles perfect. If I raise the idle though it does sound like it's slight poppin very faintly missing.

The bike still backfires alot on decel and when I cruise alone it's stutters alot.

I have purchased a jd jet kit and getting the valves checked today

They will studder on the road. If you use a 52 pilot it will decel pop less. Some say it's too large. However I usually run something like that.

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