I originaly installed the spark arrestor when I installed the pipe but after the first ride I noticed the screen had something on it. When I pulled it out I noticed it was some of the silicone that Big Gun had recommended using when sliding the head pipe and silencer together. So I pulled it out and have not put it back yet. My question is do you think the screen will reduce the flow enough to reduce HP? Do you think the screen would increase the flow enough to create a lean condition?

 

Sometimes running without a spark arrestor in a silencer designed to have one is no good. You could even loose horsepower. You might need that screen there to provide enough backpressure to evacuate the cylinder of all exhaust gases. I would clean the screen and put it back in. If your quad is running good (not lean) and you make a change to it and it is then running lean that means your change is getting you more horsepower. Then you rejet. If your change provides you with a rich condition, change it back to the way it was because you are loosing horsepower.

 

accidentally ran mine without the spark arrestor. it melted out. i checked the plug. it wasnt lean. i think it picked up a little power (just a seat of pants test nothing else) but it was silly loud.
i just sent the screen back to big gun they are gonna send me a replacement (i guess they had a few problems with the screens melting away.)

 

So if you think it picked up a little power are you going to put it back in or leave it out? Also was it power on the low end or top end? I would think that it might relieve some back pressure there for increase top end power but maybe lose some low end. What do you think?

 

I just got of the phone with Paul at Big Gun and asked him about the screen. He said they dynoed it both ways and with the screen out they only picked up MAYBE 1/4 hp. He said that the lines on the graph were so close they could hardly tell them apart. To me this sounds like it would not matter it you ran it or not unless the location that you are riding required it.

 

i have to put it back on i ride mostly at wayne national, and allegheny national forests.