Could this exhaust leak be my popping on decel. What else could it be.

CalsXS2

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This is on my 73 TX750.

I've been chasing down a popping out the exhaust. It does it some times just at idle. But more so when I let off the gas. It is in the low end rpm range.

So far I've done the following, with out fixing the popping.

1. Re-built my 72 XS2 carbs with new butterfly seals and put on there.

2. New NOS carb boots after I found an air leak.

3. Adjusted cam chain.

4. Adjusted valves.

5. Set points.

6. Checked timing. Both sides are with in 2* of each other. But then I broke my light before I could finish. Hope to get a new bulb, or borrow another light to make it perfect.

7. I re-jetted the pilots. I tried everything from 42.5, all the way up to 50.

8. Finally re-built the original 73 carbs with new butterfly seals after I still had an air leak on the 72 carbs due to a bad carb body @ the butterfly seal.

I had read about an exhaust leak can cause a popping. Well I hope the hell it can, cause I'm about to loose my mind.

This TX750 has a strange exhaust system. It has a cross over manifold on the front of the motor. And today I found a leak.

Here's the manifold.

tx750motor094_zpsad85a7bc.jpg







Here's the leak I found. Do you guy's think this could be causing my popping. I have new gaskets on the way. I'm sure open to suggestions. What am I missing.

tx750motor092copycopy_zps90cfcf89.jpg



My brother seems to think it could be the cut off exhaust that the PO did. He thinks since there's not a tip on the pipe, it could cause it. What do you guys think about that.

tx750exhaust002_zpsfda5dfe8.jpg
 
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Hey, Cal, something you could try. While idling, cover the left exhaust with your palm and feel the exhaust pulses. Then do the same for the right. If you feel an occasional pop-pop-suck-pop, you have a misfiring right side, and the instant 'suck' can pull-in air thru a leak, giving the unburned fuel a chance to fire. Sometimes caused by exh valve, sometimes by ign...
 
air "leak" at the rear of a muffler or pipe usually wouldn't cause a decel pop that leak up at the exhaust flange is the prime suspect
 
+1 leak at the head is the likely suspect. Quick way to see is thats the case is to get some gun gum or similar exhaust repair paste pop a bit on and note the results. If it stops it, disassemble and effect a permanent repair
 
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