I had just the slip-on mounted, with pro-flow with lid on @ 150/155 and it ran great. I put the headerpipe on and now it's running like this. However, before if I tried to take the lid off it would do the same thing it's doing now(coughing and cutting out). Plus, I don't the pipe getting red thing.

 

What does it do with the lid on?

 

You do too need to get the head pipe!! Look how small the stock one is,, It is not breathing right with it that small. Go with BIg Gunn full or wait for the Sparks full. They are putting out he best numbers!!!

 

What kind of numbers are the spark pipes reported at putting out?

 

No need for a head pipe unless your doing engine mods the stock one is a good design and puts out more low end tourqe than the big head pipes. A bigger head pipe will help if your looking for more mid/top but you'll loose lowend tourqe. I have rode my raptor with just a TC silencer and carb jetted PROPERLY and it runs just as good if not a little better (exp down low) than raptor with full exhaust and filter. So unless your tearing into your motor or you like the look of a head pipe and wish to get more mid/top with the air box opened up the stock head pipe is a good design. Dont be fooled by all the companies saying its so restricted and the stock head pipe is way to small because for tourqe they are flat our BSing everyone. If you ride dunes/baja where your doing 70+ then yes go with a head pipe because you dont need as much low but otherwise you wont notice any gains. I even saw a couple of people in here admitt this they first had big gun silencer then went with full exhaust and notice no gain. Do what you want but try the silencer first even if you go with a full exhaust and then put head pipe on and see for yourself.

 

Sparks wont give numbers just tell you that they do there testing by riding quad and its a huge differance. Which is fine because all exhaust are going to be close in perducing performance.

 

You had to re-jet with just the slip on.? Or did you also do some airbox mods?

 

ccarpe1, Yes mine is rejetted not sure whats in it though. I gave TC my quad so he could make a pipe and he did all the jetting he said it took him 4 tries to get it right and what a difference with the exhaust and proper jetting.

 

RAPTOR1,
What's your elevation?

 

My elevation is 770ft.