Spark arrestor question

[BenHonda400ex]

I have a stock exhaust and when I got my Four-Wheeler I had taken off the spark arrestor to look at it and I noticed that the bolts where rusted but I didn't think to much of it. Well all the bolts fell out so I got some nuts and just shoved them in there because the grooves where rusted to well I broke off one bolt and the other day I felt the cap and I felt a leak between the exhaust and spark arrestor... Well I'm wondering if that could take down some of the power because loss of back pressure? Because my dad owns a Brute force 750 and I have to admit it's quick but when you put on the itp tires on it I could just smoke right by it and now I'm pretty even with it or just dead on with him. Thanks!

[Pipeless416]

na, you're not losing an back pressure. think about aftermarket silencers.. 98% of them are straight through designs. most of the back pressure comes from the head pipe anyway.

[BenHonda400ex]

Okay then I don't know what's wrong with it then.. Maybe it was because I had a really low front tire and it was jerking the steering my valve stem started to leak around it