Hi. I have question regarding the exhaust header of my ’05 GPX 250. Does anyone know if the middle short crossover pipe in the header (marked with the X in the photo) is actually hollow through to both pipes? The reason I ask is because I’m thinking of running just a single right exhaust pipe and I wanted to cut off the left pipe (red line on photo) and block that pipe off with a metal plug. I know that ideally this is not the way to do it and that I should source a proper “2 to 1” custom header, but I really want to know if this was possible at all as I have a missing left exhaust muffler and I wanted to put bike on the road soon. I have been told by 2 people that this is totally possible, particularly if I cut the left pipe high enough so that the exhaust gases re-direct fairly early to the right pipe once they hit the metal plug. I really don’t want to cut left pipe and then find out that the middle crossover pipe is not hollow to both pipes… Thanks, Willy
I don't think it would be a good idea, it would upset you're tuning to say the least. There should be plenty of these bikes being wrecked, best to just get a muffler. You could try it by putting a cap on the end of the open pipe, of you're happy enough with the results then proceed
many people have tried converting 2-2 factory design into 2-1 by forcing both into one factory pipe one way or another. Doesn’t matter which way, it always end in disaster as you’re forcing 250cc of exhaust through tube designed for 125cc. Results in poor 125cc level performance and risks frying exhaust valves. Get muffler from breakers for $5.
Agree Danno, I've gone against the idea and left bike as is and purchased 2 aftermarket mufflers. Thanks for feedback.