Exhaust Pipe Melts/Deforms Plastic Side Cover

Troll · September 25, 2012, 14:52:17 PM

I got my stock exhaust Monday...The first thing I did, after unpacking it, was to shine a flashlight into the goat can...You guys piqued my interest. Here is what I saw...tried to take a picture, but not enough light...The upper and lower pipes, where the front (lower) and rear (upper) head pipes enter have a perforated tube, both on the sides, and at the end, extending about 8" into the can...At the end of the tubes, attached to the left wall of the can is a heat shield... I suspect this is to keep the heat down and try to prevent frying the regulator/rectifier in it's stock location. There is no cat, or real baffles. The outlet is much larger than the inlets, so, other than having the perf. cores act is minimal mufflers, there is really no restriction in it. It looks like there is enough room to get a cutting torch head into the can, if you want to burn these cores off, and remove them...

chief · September 11, 2012, 08:15:48 AM

Ok, next time you ride, check the sidecover and see if it has heated extensively. DO find another bolt for the side cover. It should recess a bit into the side cover to prevent it from touching the exhaust.

Troll · September 11, 2012, 07:54:47 AM

My exhaust is a Cobra Peace Pipe. My bike had a Vance and Hines on it when I bought it, got rid of that before I pissed off my neighbors... I think you're right about the cover touching the pipe, without that screw, it's a real possibility.

cainsriver · September 10, 2012, 23:57:17 PM

Attached are some more pictures. The gap is probably 3/8" and not 1/4" as previously stated. The bike was never dropped and the low miles are real. The fellow was a collector. He also had an older Harley with a trike conversion with 0 miles on it and a couple of corvettes. I removed the fitting and it turned out to be a longer bolt with a couple of fittings used as spacers to take up the extra length. One possibility is that the cover was removed while the exhaust was still warm or the screw had fallen out and the cover came in contact with the exhaust pipe while riding the motorcycle. The latter sounds more probable and explains the bolt/fitting arrangement as a make do. Troll you have a Vance and Hines exhaust which may be slightly different in curvature? I will continue to examine this coming weekend and get some temperature measurements.

Troll · September 10, 2012, 14:14:55 PM

I'm beginning to suspect that this bike went down on the right side hard enough to bend the exhaust hangars etc. in too close to the frame. Look for tell tale scratches. They may have replaced the heat shields....can't understand why the mileage is so low, unless it scared the owner, and he wouldn't ride it...I enclosed a couple of pictures of how the exhaust on mine fits...compare them to yours.

chief · September 10, 2012, 12:52:30 PM

Ditto what troll said... and point out the deformed area...

cainsriver · September 09, 2012, 23:05:18 PM

Tightest spot is about 1/4". I will check out the fitting versus a phillips screw. The owners manual shows a phillips screw, so not sure what this is. Will get back to you Troll. Thanks.

Troll · September 09, 2012, 21:58:45 PM

something looks fishy here...what is that fitting sticking out of the cover? Are thee really stock pipes? At the closest spot to the cover, I can still put my hand in between the pipe and the cover...your's looks way too close for some reason. Could you post another picture from farther away to give some perspective?

cainsriver · September 09, 2012, 20:52:05 PM

Attached are a couple of pictures of the area which is about 3/4" in diameter that was deformed by the heat. I could not find a pinhole exhaust leak which would have made a lot of sense as to the cause. The exhaust pipe is now wrapped with Koolmat which is good for 1000 degrees F. As mentioned the bike has very low miles on it. It was like this when I bought it and the previous owner has no knowledge as to what caused it. My next step will to get a temperature measuring device and see how hot the exhaust pipe is in that area. I put 35 miles on the bike yesterday and saw no difference in the deformed/heat affected area of the side cover. The exhaust pipes were hot, but then that is probably normal.

chief · September 06, 2012, 10:49:45 AM

I assume just baffles... I haven't actually seen the inside of one. I do have one, but hate to cut it open! I expect cost was an issue... these cat blocks get expensive due to the materials used.

greenbarn · September 05, 2012, 16:39:40 PM

Quote from: chief on September 03, 2012, 16:24:14 PM
(Also note, ALL drifter oem exhaust have goat bladders... apparently not all have cat converters inside.)

That's really interesting (I don't have one to look at - mines the 800).. So what is in the thing, just out of curiosity, if it's not a converter? Maybe it was a manufacturing "efficiency" to make them both the same, and just put the brick in the ones that required a cat.

cainsriver · September 04, 2012, 00:32:35 AM

Sorry, for the lack of responses from me, but I have been out of town. Got back late tonight and leaving early again tomorrow morning. The bike has the goat bladder but that is not the issue. Chief may be onto something as in a pinhole leak. I will check this coming weekend and I will also get pictures of where its melted is in the area of the side cover that is closest to the exhaust pipe. Thanks for everyone's feedback. I certainly learned something about the goat bladder. I already had assumed it was a catalytic converter, but now I know.

chief · September 03, 2012, 16:24:14 PM

If you have a look at the right side of the drifter, you will see how close the rear pipe comes to the right side cover. A pinhole leak in the gasket or pipe could direct very hot gases at the side cover in that area. The key is where the melting is occurring. With the goat bladder under the bike, if it were the cause of any melting it should be obvious, and would likely impact other areas as well. (Also note, ALL drifter oem exhaust have goat bladders... apparently not all have cat converters inside.)

greenbarn · September 02, 2012, 19:04:25 PM

So, Cainsriver, is yours by chance a california model? does it have a goatbladder thinggy or sheep gut or dog butt or any of that stuff?

If it doesn't have a cat , I have no idea how it could get that hot - even an exhaust leak (unless it was a BIG leak) and blowing straight on a plastic part - would melt your side cover. That is unless the exhaust is too close to the plastic. Is there any way it has gotten bent or moved??

chief · September 02, 2012, 14:36:18 PM

That picture does indeed show 3" round catalyst brick. The picture is actually a Nomad goat bladder (all 1500 nomad FI's had cats).

1999 and 2000 1500's had catalytic converters. Starting in 2001 only the California models had them. As far as I know, no 800's had them.
Sorry for any confusion and thanks greenbarn!

greenbarn · September 02, 2012, 09:00:37 AM

I'm pretty sure that looks like a cat. I'm not a bike mechanic, but 1) I can't see any other reason to have a big "goat bladder" thingy like that unless it IS a cat. and 2) that disk in the center looks just like the converter material in many cars. We have an auto repair shop and I've seen dozens of them.

The way a catalytic converter works is the catalyst causes unburnt fuel that is left in the exhaust to get burned up. That is why the cat converter on anything runs real hot. When there is a mis-fire (a cylinder not firing - thus not burning the fuel that is injected in it) or if an engine is running rich for any reason, all the extra fuel goes to the catalytic converter, and it will burn as much as can be burned based on it's capacity. It can get bad enough to melt the catalyst material all together in a lump, then you eventually end up with exhaust flow issues.

I'm not saying that's the problem on this bike, but if I had a problem with excessive exhaust temp, I'd look for a rich condition, if the thing has a converter on it. I'm not positive - but that picture sure looks like a catalytic converter to me.

chief · August 29, 2012, 12:02:08 PM

Maybe it was the baffling material they saw??

Here's a pic of the inside...

testpilot · August 28, 2012, 19:32:01 PM

Quote from: chief on August 28, 2012, 16:52:04 PM
No catalytic converters on drifters...

Oops! I thought I had seen where someone cut open a goat bladder that had a converter brick in it. It must have been something else. I stand corrected.

49Reo · August 28, 2012, 17:34:49 PM

Hopefully it is as simple as a leaky exhaust. Good luck and keep us posted; other peoples findings and repairs are our best resource.

Regards and such,
49Reo

chief · August 28, 2012, 16:52:04 PM

No catalytic converters on drifters... (except california models).

If its getting hot enough to deform those side covers there is a very serious problem... I'd also be worried about the other plastic stuff under that cover.

testpilot · August 28, 2012, 16:43:44 PM

Other causes could be a misfire or too rich causing the catalytic converter to overheat. An over-rich condition can be caused by a false temp signal causing the ECM to think it's running cold. Stale fuel can cause the engine to misfire and run poorly. These things can cause the cat to get fuel saturated then suddenly light off. I saw this happen on an early 80s MG. It was ran for a long time with the carburetor adjusted all out of whack. I was asked to set the carb up. When I did the final tuning of the idle mixture jet and I hit the sweet spot, the engine smoothed out. Then, all of a sudden, the catalytic converter and exhaust pipe lit up and glowed cherry red like it had a blacksmith's fire inside. It lasted about 30 seconds and then cooled down. That cat must have really been saturated. Just some thought starters...

chief · August 27, 2012, 11:46:16 AM

Wow, I have NEVER heard of such happening. I think you have another problem.

I'd be worried about engine heating, but would likely inspect the exhaust thoroughly looking for exhaust leaks that might be directing hot exhaust gases to the side covers. I'd also check the temps on the cylinders...

cainsriver · August 26, 2012, 23:35:27 PM

Today I noticed the stock exhaust pipe had melted/deformed an area about 3/4" diameter in the right side cover where it is closest to the exhaust pipe. I removed the heat shield and wrapped the exhaust pipe in that area with a piece of Koolmat 6" long that can stand up to 1000 deg F (held in place with 2 hose clamps. Anyone else have this issue. Is there another problem and I am disguising it? This is on a 2003 Drifter 1500 with 165 miles on it.