I was thinking about last week when we were talking about the R-6 with no end can and if it was going to hurt it or not. In my instructions for my Yoshi pipe it showed some graphics and explained a little about richness and leanness. Basically it says that Gold is good. If your pipes turn gold then thats perfect. If your pipes turn blue or purple then, your running a little lean and should get it fixxed but , not necesary all the time. If your pipes glow then your fucked. Way too lean.
It's not going to hurt the bike too much w/out the end can but, your performance will lack from the lack of backpresure through the system unless you jetted it that way. The jets / E.F.I computers are set up for a certin air fuel mixture and with less back presure from the exhaust, then air can travel more freely and then you end up getting the improper mixture for combustion.
It's really interesting how sensitive these things can be. I ran mine with the stock can, my Yoshi, and then nothing. I can really feel a big dif between the 3 one right after the other! I have EFI so the computer can adjust for the dif pipes but, if you have carburators then, thats why you have to re-jet after changing pipes. Yamaha was always praised for their perfect carburation which is why they took so long to go to EFI. If your going to run it with no pipe then just watch the header for color or glowing.
Golden rule!!!!! Gold is good. Blue and purple should be fixed but, not necessary. Glowing , your screwed. Thats how it was explained to me.
The Yoshi bolt on gave me 10 more horse and 3 foot lbs of torque.
