Bonneville America Forums Forums Technical Forums Exhaust Partial Bafflectomy...

Folks: I'm hoping some advise could give me some piece of mind. I have an 05 America. I wanted to experiment with removing some baffles, so I put a spare set of pipes on the bike. The pair is a set of the newer tappered (spelling?) exhausts with the catalytic converter on them. On each side, I removed the last baffle and drilled three holes in the second. Desired sound was achieved and I swear the bike is running better. After the procedure, there was no backfiring on deceleration and the bike pulled nicely regardless of the throttle (ie no dead spots). Based on this I took it out this weekend for abound 150-200 miles. When I arrived home this evening, I noticed my pipes were more "blued". The AI has already been removed. I'm taking this as a good indicator that the bike is running too lean. I will put different jets in it now, however, I'm curious could this have damaged the engine or put extra wear and tear on it. Trying not to worry, but feeling kind of stupid right now. Any advise / consoling words would be helpful.

When you open up the exhaust, the motor will be able to breathe out better, and that's why you get the performance increase. As far as the jets go, you should move up probably 2 sizes. I'm sure you didn't do any damage to the engine, they are pretty tough. But it probably was running hotter than it should have been and that's why you saw the increase in the blueing.

No worries, you are a little lean now and thus running a little hotter. I wouldn't keep running it that way but I'm sure you didn't hurt anything.

Roadworthy and Dog,
Thanks for the reply. I finally got the courage up to work on the bike myself and almost sh#t when I saw all the blue. As you can tell, I'm still learning. Concerning jet sizes, it there a decent guide I can use or how can I look up the sizes to know? I'm sure experience is the best teacher, but was curious if this is going to be a "trial and error" type thing. Been stuck in the old choice of baffle removal vs buying after-market. Just heard the new B/C Cocktail Shakers and love the sound. Pretty temping, but more money then I feel ok about spending. However, now after riding the bike with it breathing, I don't think I could go back to the originals. So if its trial and error, it looks like I'm going to be taking a few swings...

There is some trial and error involved but Dinquas jet calculator can take quite a bit of the guess work out.

unless you have a mac

In that case Dave, there are plenty of us here who have it to run the numbers for you.

well turn my upside down!

You don't have to have a PC. There's a web version.

http://www.friarsride.com/techwiki/jetting-calculator/

Or sans Friar cruft:

http://friarsride.com/dinqua/

No options for engine work? Basically only intake and exhaust? No worries, mine is pretty dialed in, but that was the first time I've seen the calculator in action.

Talk to Pat. I just translated it to the web.