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Rubber like odor after installing Laser slip on for 03 R1100s Replika

plexiform

New member
I've purchased a used 2003 R1100s Randy Mamola Replika with 15,800 miles. Overall condition very good. Only things I've seen that give me pause are:

1. Side body cover with areas of heat damage at the points closest to the cylinder head. Is this the burning rubber smell? Although I made some rides before replacing the muffler and did not experience this odor.

2. I just replaced the stock dual muffler with a Laser slip on that was apparently taken off a 2004 when it was still new because the original owner wanted a different exhaust. So Laser muffler has been sitting at a BMW motorcycle dealership since 2003.

My first ride after replacing mufflers when I pull in to the garage I smell a 'burning rubber' like odor. Doesnt seem to have any obvious areas of contact. The smell is definitly coming out of the muffler as thats where the odor is strongest 20 minutes after letting the bike cool. Engine case and cylinder surface temps checked with laser temp guage shows anywhere from 170-210 degrees F. I mention that because I dont know what is normal so any thoughts would be appreciated.

So here are my questions:

1. Why the rubber-like smell?

2. Should I expect areas of heat damage on the plastic bodywork close to the engine? If not any thoughts to what is causing it?

see pic of which area I am talking about that seems to be gettign heat damage.

http://photo.net/photodb/photo?photo_id=16685672

Any help you can give me would be great.
 
I'm not familiar with your model but changing the exhaust could certainly change the exhaust system tuning. That could lead to some additional heat in the area of the exhaust manifold. You might try measuring the exhaust manifold temperature with the stock and then the aftermarket exhaust.

Nice looking motorcycle!
 
The wire harness for the license plate light runs between the two mufflers.

When replacing the muffler I ran it the same way as before right between the two mufflers. I heat shrunk the 3 wires (license plate light, and each turn signal) together so it would be cleaner trough that narrow opening between the mufflers. Possibly the heat shrink sheath is the source of the odor? But it was like that before as well.
 
should not have that smell-
rubber donuts holding the muffler in place all good and all the way in?

the heat damaged fairing panel is from some idjit letting the bike warm up before riding it, or sitting in traffic, unmoving, for extended time. don't do either of those things.

adding the laser cans should not effect heat from motor one iota. however, keep an eye on your plugs, or get thee to a dyno. these bikes run quite lean from the factory, and decreasing the back pressure will flow more air thru the system, thus leaning things out even more. if it's a problem, contact Robert Foster (you can find him as "boxercup" on the Pelican site- THE place for info on this bike. He's the importer for Laser, and has/can get the needed chip for it. http://forums.pelicanparts.com/bmw-r1100s-r1200s-tech-forum/

see ya there! :wave
 
rubber donuts holding the muffler in place all good and all the way in?


I couldn't get the slip on to slide all the way in. I tried my best and tore an intercostal muscle in the process. Any tips on how to not break a rib trying to make that happen? They probably have less than an inch more to go. Can't tell for sure but the new cans are about an inch or little less more out towards the back than stock.
 
Any chance you're getting air infiltration at the junction? Without meaning to state the obvious, something is getting hotter, that usually means unburned hydrocarbons are finding oxygen in the exhaust and burning.

Our bikes (at least ones with stock O2) sensors all run the same leannessÔÇölambda=1, which for gasoline is an AFR of 14.7:1. That mixture produces the hottest exhaust gas. Make things leaner, and the exhaust gas gets cooler. So your problem isn't heat from leaner mixtures from flowing more air. But it's possible that at times some unburned richness is burning in the exhaust.

Another possibility is that the lazer slip-on allows air to find its way from the tailpipe into the exhaust interior due to a change in tuning based on that slip-on's design. That I don't really know.
 
Any chance you're getting air infiltration at the junction? Without meaning to state the obvious, something is getting hotter, that usually means unburned hydrocarbons are finding oxygen in the exhaust and burning.

Our bikes (at least ones with stock O2) sensors all run the same leannessÔÇölambda=1, which for gasoline is an AFR of 14.7:1. That mixture produces the hottest exhaust gas. Make things leaner, and the exhaust gas gets cooler. thanks, did not know that. So your problem isn't heat from leaner mixtures from flowing more air. But it's possible that at times some unburned richness is burning in the exhaust.

Another possibility is that the lazer slip-on allows air to find its way from the tailpipe into the exhaust interior due to a change in tuning based on that slip-on's design.That I don't really know.

Roger, i've got a full Lazer system on my bike. I might have an anser for you.. but i'm not sure what you are suggesting here. Air coming in where, and flowing to where?
 
The OP mentioned that he couldn't get his muffler all the way onÔÇöif I understood him correctly. So I wondered about an air leak there. I've never designed an exhaust but I understand that exhausts are tuned systems and that although the net flow of exhaust is out the tailpipe, that pressure wave flows forward until it finds a turn, expansion or constriction, and then a pressure wave flows backward for a short time. I wonder if that would allow any fresh air entering the system to encounter unburned fuel.

It would be great to have a Wideband O2 sensor attached so that residual exhaust oxygen could be measured on a bike that had exhaust heating after changing mufflers, etc.
 
The OP mentioned that he couldn't get his muffler all the way onÔÇöif I understood him correctly. So I wondered about an air leak there. I've never designed an exhaust but I understand that exhausts are tuned systems and that although the net flow of exhaust is out the tailpipe, that pressure wave flows forward until it finds a turn, expansion or constriction, and then a pressure wave flows backward for a short time. I wonder if that would allow any fresh air entering the system to encounter unburned fuel.

It would be great to have a Wideband O2 sensor attached so that residual exhaust oxygen could be measured on a bike that had exhaust heating after changing mufflers, etc.



I bet you're right about air getting in at the connection point between slip-on and down pipe. I recall seeing a tiny gap and thinking if I covered it with the clamp I would be fine. I didn't for a second consider the advanced physics you've suggested. I will get back in there and fix the gap. Any ideas how to push the slip-on further on to the two pegs holding it in place without me injuring myself again?
 
It's a long path from the slip-ons to the exhaust manifold. So I don't know if its a leak or change to the exhaust tuning or if perhaps something else is the cause. I took a shortcut and used an explanation based on the change you made and the slip-ons not sliding all the way on.

For the exhaust manifold to really heat up, you need something burning in the exhaust manifold. The job of the catalytic converter is to oxidize (burn) CO and unburned hydrocarbons (fuel). If during high power operation (when the mixture is rich) air finds its way to the area that's overheating, the slight amount of unburned fuel and air combine and you get a very hot reaction. I would look to see if you have any leaks nearer the exhaust manifold too.

Another possibility is a slight misfiring causing unburned air and fuel to be present in the exhaust manifold.

All this is assuming the overheating isn't due to warming up a stationary bike.
 
Is there any chance a mouse started storing stuff in the mufflers when they were in storage at the shop? Some type of rubber or plastic.
 
regardless of air leak or not... this all still comes back to"wht's the burnt rubber smell?". check the condition of the fairing right after a run; if it's not feeling a bit soft and you can't smell it coming from there, then the only other source could be is a misrouted electrical wire that's getting torched (and it won't take much of that before something stops working correctly), or the nylon muffler hangers themselves. Or, as jsut suggested, mice leaving presents. there is precious little of rubber/plastic composition in the vicinity of the exhaust system that can be causing it. fwiw, i have a slight exh leak on my bike, at the upper cat pipe connection- i'm running a cat eliminator- and have never had any funky melty smells eminating from the bike.
 
+1. I went back and reread the symptoms. Makes me wonder if something dropped I to the down tube when you replaced the mufflers.
 
Would it be a bad idea to use some wd40 on the pegs holding the slip on in place to help get sliding easier?

I didn't hear anything rattling in the new mufflers before in stalling them but I will check that out.

Why did BMW route wires between two hot mufflers and what is the solution? I can't see any other direction to route them.
 
Would it be a bad idea to use some wd40 on the pegs holding the slip on in place to help get sliding easier?

I didn't hear anything rattling in the new mufflers before in stalling them but I will check that out.

Why did BMW route wires between two hot mufflers and what is the solution? I can't see any other direction to route them.

WD-40 shouldn't hurt a thing...I use it to get other mufflers on at times...it will smell like a fish fry for a few minutes:whistle

I went to the auto parts and bought a roll of 1/2" high temperature jacket tubing ( fairly expensive) when I added some additional hyperlite brake modules on ours...there really is not many options for routing on the S to have a clean look.
 
Thanks for all the replies. I rechecked today and there is no gap between the down pipe and slip on. I smelled the odor in the mufflers and started the engine for a minute. A little smoke, nothing black the odor seems to die down after a minute. I didn't keep running it too long because of the heat getting to the front bodywork. I'm hoping when the rain stops and I ride it again the odor is gone. Maybe something in the mufflers has burnt away already....who knows. Haven't taken the down pipe off. Hope I don't have to. But the inside of the muffler is crystal clear....looks unused. Thanks for the all the replies. This is truly a precious resource for any BMW rider!
 
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I would definitely put miles on it before becoming concerned with the smell, bugs, rodents etc all like to crawl into stuff in storage and store stuff or die. lso they could have sprayed wd40 or similar product on the pipes to keep corrosion away. Checking the turn and LP light wires good advice.

As far as getting it to fit, soft 2x4 and a big hammer, I would think the lasers are robust enough to use this method, my Staintunes were, you just need a 2nd person to help guide the pipes.

Discoloration, as mentioned, is from someone letting the bike idle too long. These bikes are AIR COOLED, they should not idle for long periods of time they will get hot if you do.

Enjoy the bike, the best looking BMW IMHO.
 
Rubber like odor is going aways after putting some more miles on the bike. I bet it was the stainless steel polish used to shine it up.
 
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