just put a set of RCX slip ons I got used from my buddy. The rear head pipe splits right off the head and nothing on the left side is warming up. All is cold to touch. Is this and issue? Never checked with factory mufflers on.


2006 ultra all original except slip ons. Still factory head pipes

 

On Harley's with the stock mufflers or aftermarket slip ons the temps should be relatively the same between the two types of mufflers, but there will be a slight difference due to packing etc. Factory mufflers are designed to fit only one side. Yes you can flip them from side to side, but in some factory mufflers the right side ( as you sit on the bike ) flows more exhaust then the left. So you want to get the right one on the right side. That shouldn't really be a problem with aftermarket as they have less restriction. But that being said,if at idle you put your hand at the rear of the muffler you should feel exhaust gases coming out the rear of both mufflers. The right side will be a bit stronger but that is by the design of the stock exhaust system. As you rev the bike up the two sides will even out more.

So if you are having no flow, ie: no increase in temperature on the left side something is wrong. I assume you are still running the stock header pipe set up, with the cross over pipe on the rear cylinder?

Is the rear cylinder working or do you have an ignition problem, that is about the only way you could get no warming on the left side. Is the left side plugged in some way? Shine a light down the muffler and you should be able to see light coming out the other end. The less restrictive aftermarket ones will be more open and the factory ones will just have a small hole in the centre of the baffle at both ends.

 

Think your 06 is like my 04, in that the left pipe may as well not be there.

The exhaust pipe from the rear cylinder aim’s straight down to the right pipe. The left pipe is a 90 degree tap onto the main pipe, so hardly any exhaust gasses make that 90 degree turn and go down the left pipe.

The front cylinder also feeds into the right pipe.

So at best, the right pipe gets 1-1/2 cylinder, the left gets 1/2 cylinder. Of course the temperatures are different.

 

The factory head pipes are a disguised two into one. Most all the exhaust exits the right side.

 

I took it out for a spin. Seems to run fine. The y-pipe on rear cylinder gets hot on right side but you can grab the left side bare handed. Exhaust is exiting both pipes. The right side is extremely hot in my opinion. My buddy said it sounded muffled when I went by his house .

 

I'm confused. Are you talking about the headpipes, or the pipes and mufflers after the cat? I wouldn't expect the headpipes to differ very much, unless one cylinder is not firing.

 

[QUOTE=Classicsporty;21003318My buddy said it sounded muffled when I went by his house .[/QUOTE]
probably why he got rid of them.
j/k..I've never heard them.
lol..wonder if he ever heard them on his bike while someone was riding.
also..i think your bike is fine. good luck with her!

 

Yes they were on his bike he just went a different route due to his build. And it was another friends house I went past.


but yes everything from the head pipe to the muffler is cool to the touch on the left side. There is exhaust flowing through it. No cats on this year model. Has y-pipe on rear cylinder

 

No, it has a T-pipe. The exhaust flow is not split equally to both mufflers. Instead, the pipe directly flows to the right muffler, with a side tap to the left muffler.

 

No matter what at some point in time, the left side header pipe should get hot to the touch as it goes down the side of the bike to the left muffler. If you can get your hands on a hand held laser temp tester, you should be able to check the temps on both sides. On a fully warmed up bike at idle, there will be a difference between the two sides of the rear header pipe, but it will tend to equalize as you go down the highway.

By design as others have noted the bulk of the exhaust does go out the right side on a stock harley exhaust system. In numerical terms something like 75-80 % our the right side and the remainder out the left when the bike is at idle. On my 98 Evo with stock mufflers, at idle you can feel a slight difference between the left and right exhaust as it exits the rear of the mufflers. As you rev the bike up this gets more even.

With the stock rear cylinder Y header or T header what ever you want to call it and due to the restriction in the stock mufflers, the exhaust gases flow to the right muffler until the resistance inside that muffler forces the gases to take the less restrictive route to the left muffler. This is called back pressure. It also provides the potato, potato, potato sound that Harley's are known for. On some year bikes if you get the right and left stock muffler mixed up, the bike won't sound right and likely won't run right.

The earlier bikes had much less restrictive stock mufflers and as the bikes got newer, the mufflers got quieter. If I look down my stock evo mufflers and compare them to a set off an early twin cam, the mufflers look the same externally, but internally the center exit hole in the baffle on the stock evo mufflers is at least twice the size of the one on the twin cam muffler. Neither set of mufflers have been molested. Both sets of mufflers have different part numbers. I've run both sets of mufflers on my bike and the stock evo ones are just a bit louder at idle and going down the highway. The bike seems to run better with them on, no doubt due to slightly less restriction. When checking mufflers a Harley parts fiche can be a big help. Sorry for the long winded reply. Not hard to tell its winter up here.