DWB, Is your QS1 a "half-system" or does it have the front header pipe with it, and how much are these pipes costing now? ......Also 124/128 mains, even if they are DJ mains seem lean, I would think around 132/136 would be needed...I guess the Dyno's don't lie and most of us are running around too rich........what would the 124/128 DJ's be equal to in a Keihin? I would think about 135/140......

 

Not sure STAKK. I know I had another spring in once and it gave me higher rpms but I know the speed couldnt have been much if any faster and possibly slower than the 68mph.

I guess what Im getting at, without the tach the rpm related to speed is hard to determine even on the same atv if different primary springs are used. I would guess you are in the 8500 range.

 

Yes, it is just a slip on and not full. I would find it hard to believe that a full would change much though. I did not have the spark arrestor installed either. You have to remove the arrestor to measure AFR at the dyno. I think the slip on runs $290ish. I wouldn't bother if I was paying retail. I would stick with stock or go for a loud wide open exhaust if a person insists on getting one.

Stock vs QS1 slip on

I was told to add 13 to the dynojets to compare. So, I would think 135/140 kiehen might be close. Which is pretty close to stock.... Not the needles though. The dynojets are shorter.

 

sounds like even with the Dyna, the stock cam timing is keeping the rev's from peaking, I'm like KOD and think that my rpm's now are probably 8500-8600 rpm......It will take other cam's to get full potential, if the V cams and Dyna will allow you to get to 9000 rpm, you are close to the 9200 limit anyway so with that I question if the Penland or Web cam's offer any real performance over the stock V cams?now if we went to the higher lift and dration and timing of the web V cam's NOT the web Prairie cams we might see acceleration improve, but top speed looks like can be acheived with the V cams and Dyna and normal mods.....If I can get 71 mph at 8500-8600 rpm, I would guess that 9000-9200 rpm would equal 76-78 mph....anyone agree??????