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Discussion Starter #1
hey, im not that engine smart and i have this odd burning smell coming from my bike lately, well though most of the summer actually but now that i have the time to fix whatever is causing this, i would like to so here's my question.
I have a 99' 750SS and i notice it most right now when i start up my bike, let it warm up for ten minutes then shut it off... The right side muffler will have a very chemical/plastic burning smell coming out of it for about 5 minutes, and it will smoke for 5 finutes too... the left side is fine and normal.
Now its easy to tell that the bike was dropped on its right side and then repaired but the dammage to the muffler can is some small cosmetic scratches and only now can i see a tiny exhaust leak at the front of it because its so cold out right now the exhaust turns to steam instantly.
So the facts are atiny exhaust leak out of the can, bike was dropped not bad on right side but everything else looks repaired... long after bike turnoff bad smoke and burning smell out of right side muffler only... any ideas on what could be causing that or what else to test to get more symptoms out of it?

Any suggestionsguys would be appreciated. Thanks.
 

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I had a problem just like that with my CBR1000RR. In the end I found out my buddy had stuffed a styrofoam cup down the pipe and it never blew out.:mad:

Also make sure to check where the exhaust pipe exits from under the lower bodywork. There isn't much clearence there and some aftermarket pipes are prone to scorch the edge of the lowers.
 

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Discussion Starter #3
yes my bike is affected by that problem but right now my bike is naked on the stand in the garage. today i let it run again and got the same bad burning but i noticed droplets of a liquid of some sort inside the pipe that smelled bad and might be the cause of the smell so i am gonna take off the exhaust pipes and run it again and see if i get the same smell, if not then the new pipes go on. I was thinking that today that it would take just one jerk to toss something or some fluid in there to cause that sort of crap.
 

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My guess:

The liquid is condensation.

The fuel and air burning in your engine (O2's combine with some of the Hydrogens from the HydroCarbon fuel "gasoline" we run) actually MAKES water... Chemistry is cool.

Your pipes are cold -the steam produced condenses and leaks out...

SS's are FAMOUS for the "right pipe smoke" when cold. They all do it. (Okay, ...Well, most of them do.)
You may notice in hot weather the muffler runs hotter on that side too.

A cold motor with not enough fuel runs lean and that exhaust will burn your eyes/smell foul.
Check your CO (idle mixture) when warming up and I bet you'll find it there.
 

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Discussion Starter #5
k WHAT? sorry i didnt understand most of that. what would possible cause the right side to smoke and not the left since the exhaust goes through the X pipe at the bottom? and how do i check my idle mixture?
 

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lol
just brought back a fond memory of riding a friends bike. when I stopped and shut off the engine a flame would start burning out of the right side exhaust canister. start the bike and it would go out.
turned out he had a leak at the forward edge of the canister, after riding the exhaust packing would burn. The hole was giving the packing O2 at just the right spot for combustion.
he re-packed the muffler, sealed the hole and problem solved.

just food for thought.
 

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Discussion Starter #7
thats very possible... if the padding has shifted around i dunno... just curious what materials are in muffler packing?
 

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Depends on the pipes.
are they oem or aftermarket.
Oem uses a mechanical baffle as well so the packing lasts a long time.
It is like a 1-2mm thick wrap around a very large mesh core.

Aftermarket can be hit or miss. Arrow uses some of the best packing material I have seen, some use packing that looks like someone stole insulation from their attic.
Dirt bike packing is usually too loose and burns out quicker. this is what most people use when re-packing.
A backfiring bike will blow out the packing as well, It is common to find a hole in the packing an inch or two up from where the pipe meets the can.
 

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Discussion Starter #9
they are oem... but i have a set of takeoffs from a 900SS that i got off ebay that ill go try swapping on and see if that makes a difference i guess... it cant do any harm can it?
 

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Discussion Starter #11
thats a really good idea... just curious what kind of differences will swapping from the 750ss oem cans to the 900SS oem cans make? like will it burn richer or leaner causing loss fo power? not enuff backpressure?
 

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It will lean things out a bit.
oops did you say oem to oem? no change.
if you know a welder/ fabricator you can core either of those cans and make them perform as good as any aftermarket slip-ons.
key to coring is to do it right, no slash and burn pipes.
get or make some perforated tubing a little bigger than your outlet, cut out the old core and install the new core , wrapped in good packing .
ta-daa great sounding pipes that cost you a couple hundred.
 

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Discussion Starter #13 (Edited)
that does sound awesome but alas no fabrication welder friends at the moment that i know of...

ok i just took off the exhaust and started it up just to see how it sounds and wow what a difference! i never considered aftermarket exhaust before now but i think im gonna have to get a couple pipes if i end up keeping it all next season!
With the lack of backpressure from runnign mroe open pipes how do you compensate?
 

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Discussion Starter #15
hey so the new pipes didnt fix the burning problem but they do sounds a bit better, less rattle. Anyways i realized that the burning will come from the left muffler if i leane the bike on its right side so i guess that means its somethign int he engine right :( that sucks any ideas what i should do next to try and figure out what could be causing this odd burning/smoking?
 

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the dont really narrow down the possible scenarios of how to isolate the problem

Yes they do.
In fact, the good ones specifically have sections on troubleshooting.
I know Haynes manuals do.
I haven't read LT. Sniders maintenance manual (probably the best book out there on these bikes at this point in time) but I would be shocked to find he didn't. It gets great reviews by everyone who has used it.

The factory manual will have no use to you until you have a good grip on what is going on.
It asumes you know what you're doing and have training.
 
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