Bonneville America Forums Forums Technical Forums General Tech Aftermarket Baffles on Stock Pipes

Has anyone tried to add aftermarked baffles to their stock pipes? I've got stock pipes that were hollowed out by the previous owner, zero backpressure. I've been told by the dealership that I'm losing some horsepower by not having any baffles for backpressure. I'm wondering if I can just get a couple of $5 bafffles from JP Cycles and put them in my hollowed out stock pipes.

Thanks!
John M.

Just rejet if you want more power. It is a longshot that any baffle you put in will have the exact amount of backpressure to work with your current jetting, so you'll end up rejetting anyway. For all you know, the previous owner rejetted wrong when he gutted the pipes.

Yeah, the bike has been in the shop for rejetting twice. The first dealership put in 45 pilot jets and the bike ran like crap and would take 6 or 8 revolutions before it would sputter and start. The second dealer put 40 pilots back in and 120's for the mains. It runs great now, but I've been told that having some back pressure will add some power back to the bike. (it seems a little weak in the mid throttle range, according to them)

Would their eyes be brown, by any chance? Because they are full of sshitt. Midrange is adjusted by the needle. Check the Tech Vault.

If you have 40s (smaller than stock) and 120s with gutted pipes you are running WAY lean. First thing I would do is check to see if the reducer cone was left in or not. The reducer cone will provide some back pressure but you still need larger than stock jets.

So, how the heck do you know if you have the right size jets in? Are there symptoms to look for if it's running lean or rich? The bike seems to run great right now but how do I know if it's setup right?

The best place to start in in the tech vault. Go to pats carb page and there is a jetting calculator. It's usually right or atleast close. It lets you enter you elevation and the changes you made and tells you what jet you need.Here is the page.
http://www.dinqua.com/index.html

Yeah, the Jetting Calculator is saying 128 for the mains. I guess I am running lean. The bike runs great though, what are the symptoms I should look for? Or should I just leave it as is since it seems to be running so well?

It's up to you 120 to 128 isn't huge so you would probably be OK, If it was my bike I would change the jets and go put it on a dyno.