Aftermarket Exhaust Question

Yamaha FJR Motorcycle Forum

Help Support Yamaha FJR Motorcycle Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Benjammer

Well-known member
Joined
Jun 8, 2010
Messages
80
Reaction score
0
Location
NW Arkansas
I put on a set of Two Bros. Titanium black series on my '10. I did do the barbarian jumper mod and bumped the fuel up a little but didn't add a power commander. It has been running fine now for over 11000 miles. I did take the PAIR system off. I have no popping on deceleration.

 
I put on a set of Two Bros. Titanium black series on my '10. I did do the barbarian jumper mod and bumped the fuel up a little but didn't add a power commander. It has been running fine now for over 11000 miles. I did take the PAIR system off. I have no popping on deceleration.
Pilot Thanks for the info. "If" I go with the slip ons I'll probably leave the Pair system in place. Hopefully won't have issues. Hard to believe that just by replacing the stock exhaust could cause that big of a difference.

 
The bottle neck is the cat/con. In pre-2013 that's in the collector under the frame at about where the rider's pegs are. In the 2013 they may be in the cans themselves. Unless you open up the exhaust section with a complete header-back system, there's no need for a remap just for slip ons.

I have popping on both my FJR and my Subaru STi as a result of exhaust mods (slip-ons only on the FJR). It's the air injection and how after market cans do less to mask the cumbustion of extra fuel when dumped as the throttle is chopped. With the STi, I need to be heavy into the boost and chop the throttle for it to happen (Stage 2 with complete intake and exhaust mods, custom tune, etc.). Wicked when it happens though.

 
Last edited by a moderator:
The popping is there whether you have stock cans or not. It's an emissions system to consume unburned hydrocarbons that get out of the cylinder with the exhaust gas, and is a bigger problem with cold engines since they run so rich when cold. The system allows air into the exhaust stream to provide oxygen, allowing the excess hydrocarbons to burn in the exhaust pipe instead of coming out into our fresh breathable air. An aftermarket exhaust system makes the popping "worse" simply because you can hear it better in a less restrictive muffler system.

The exhaust doesn't cause popping, it makes it more audible. The popping is not an indication of something wrong with the engine.

 
Last edited by a moderator:
The popping is there whether you have stock cans or not. It's an emissions system to consume unburned hydrocarbons that get out of the cylinder with the exhaust gas, and is a bigger problem with cold engines since they run so rich when cold. The system allows air into the exhaust stream to provide oxygen, allowing the excess hydrocarbons to burn in the exhaust pipe instead of coming out into our fresh breathable air. An aftermarket exhaust system makes the popping "worse" simply because you can hear it better in a less restrictive muffler system.
The exhaust doesn't cause popping, it makes it more audible. The popping is not an indication of something wrong with the engine.
+1: great explanation. When I put SkooterG's old Staintunes on my 05, I noticed the popping right away, especially with the baffles out. Crank up the R's, chop the throttle shut, and it sounds like popcorn... for the first mile or so. Afterwards, when the bike warms up, I rarely hear anything. It's totally a NON-ISSUE. I left the pair system alone as I'd like to do my part keep those unburned hydrocarbon levels down. Don't shoot me here, but I'd like to keep America beautiful. Guess I was raised to respect something that it seems nobody has ever mentioned before on this forum. It's one of the reasons that I don't mind hearing the popping when I first start up the bike. It's a reminder to me that I'm doing something to make a difference. Call me crazy, fine, but I feel good about that. Besides, I actually like pop corn.

Gary

darksider #44

 
Top