670 jetting and tuning

[woodsRIDER92]

iv finished up my 96 670, i put a long track 151, droped and rolled the chaincase, move the skid back 2", 2 wheel kit, gutted the silencer, 9tooth extraverts, short carb boots, im playing with the clutching right now and about to gear it down the chaincase to a 20 tooth gear.

but my one big question is i cut rotary valve to a 501 rotary valve, before when it was a stock sled beside 44 helix, gutted air box and ufos i used to get 80-90km to a tank of fuel, now im getting just above 60km is this normal? A friend of mine said that the jetting is probably off soo for you guys running 501 plates wat is your jetting set at? mines at 380 and 390 main jets and 17.5 pilots. and how many km are you getting?

the sled goes way better than stock right now but id like to last longer out in the mountains, if the jetting doesnt help me that much im thinking of finding another stock rotary valve

any help is appreciated
thanks alot

 

[Modman]

Depends on what elevation you are running at and does the sled have the HAC on it? If its just carbed with no HAC I'd say you are still probably rich, you need to look at the plugs and piston wash.

I run 330-350's in one, but I also have 560's in the other motor....

You can always pack gas.

 

[woodsRIDER92]

i still have the HAC in it, the last ride i forgot to check the plugs since i was having too much fun with the sled :d

is it normal for the fuel milage to go down that much with a 501 plate?

 

[magnet]

i have a 99 x model. with prety much the same modds as yours. out here in the flatter land i get about 100-130km to a tank and shes done depending on snow depth and weight. so yours is probably about the same when you factor in the always climbing aspect of it all.

 

[Modman]

i still have the HAC in it, the last ride i forgot to check the plugs since i was having too much fun with the sled :d

is it normal for the fuel milage to go down that much with a 501 plate?

No, the 501 plate should drop it some but it shouldn't turn it into a 60 km trail sled, which is why its important to check the plugs and see what the jetting really.