Heres a new one Exhaust pipe

[wallywheels]

So I will start off this XS 1981 was built by me and my brother in 1 weeks time from stock to this I did the build for 1800.00. Ok to the point I did not know if the bike ran when I disassembled but upon reassembly it fired up great after some minor repair work to electrical and with aftermarket carb as you can see. BUT after I put the final "somewhat custom" assembled exhaust on (not the mock up exhaust as I had the first time it ran good) it decided to not run very well and oil was squirting out of the open valve covers like crazy only on the right side. Me jumping to conclusions decided a valve was stuck on the exhaust and that it was a fluke it ran well in mock up. So after some tinkering off came the head and a rebuilt top end coming up with no issues accept light rust on piston rings. Restarted bike and same thing!! I was pi$$ed so I slept on the issue coming up with I still had a bad valve, or worse, or the exhaust was not allowing air through. Well after hours of searching I found what you see below I have never seen anything like it. The inner pipe looks rusty but it is not like tissue paper it is still solid steel but only the inside pipe. This was the issue but I still cannot figure out how this happened. Heat had to have played a factor as the steel would not even bend with heavy screw drivers trying to pry it back in place. To remove it I cut the pipe in three places and slid this thing out anyhow problem fixed runs like a top now!

 

[Johnt3]

Holy crap! No wonder it didn't run worth a damn. That is crazy man. I'm thinking I would have been all over the engine before I found that one too.

 

[wallywheels]

I am hoping that is why I got the bike for so cheap they said it didn't run right so it sat. I am glad to hear i'm not crazy thinking it was engine related.

 

[tonyc]

Good find Wally! Tony C

 

[racerdave]

When it was running bad, did the exhaust have a pft pft sound or a whistle?

 

[Johnt3]

 

[weekendrider]

I've never seen it (till now I think), but it is said if you block the bottom drain hole in double walled pipes water will accumulate and if it freezes in collapses the inner pipe.

 

[wallywheels]

That actually sounds like a possibility but it is so far crushed in it would have had to happen multiple times.

 

[peanut]

thats amazing! unless you had run the engine on the other exhausts without a problem, you'd probably never consider a blocked exhaust

 

[Johnt3]

I was talking about this at work and water freezing in there was a idea we had.
Was the bike sitting for a few seasons?

 

[wallywheels]

Because I ran a different exhaust for mock up it was probably the only reason I found it. I ruled everything out till I got to the exhaust and thought there is no way but when I pulled them off I tried to blow through them and it was extremely resistive almost not possible but I blew through the tip and when you do that the air can go around the inner pipe and out the upper cooling holes so that was the only air getting through. The way I did the exhaust was cut the cans off stock pipes and weld on straight pipes to them so the inner layer was just there and ended where the new pipe started

Johnt3: I beleive the bike was sitting for a long time I purchased it form a friend who purchased it to build a bobber. He was told it didnt run.