yea be warned you will end up thinking, right just done this mod what next!!!!!:048:

I have a distinct feeling you maybe right on that one mate.

:YellowCrazy_J8GDC6:.....sorry if I seem a bit stupid. To clarify are you saying not to use your fuel mod for my model because ECU is better and try to go for power commander & fuel map instead? Would changing filters/airbox in you mod make a difference without a power commander as power commander seems expensive? Just needs clarification. Thanks.

Stage 1 & 2 filters with my fuel mod will show a good result on your bike, but the best result is from a Power Commander with a custom made fuel map made on the dyno.

Thanks Kev, that clears that up.

Fuel mod needed ?
 

I already have a K&N Stage 1 air filter installed and am thinking of getting the DNA Stage 2 air filter. Would this be OK to fit without playing around with any of the fuel mods or mixtures ? I am really irritated by the surging and would love to improve the power, especially low down.

2 main ingredients of an engines combustion is air & fuel. By adding more air only will burn off any extra fuel & create some extra HP, by adding more fuel & air to the combustion will produce alot more HP.

By nature the XT660X/R motor is to lean already, by fitting a stage 2 filter with no fuel mod will make the A/F even leaner & make the surging worse.