Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums - View Single Post - Help Diagnosing where my exhaust leak is
View Single Post
post #1 of (permalink) Old 06-27-2011, 01:53 AM Thread Starter
Members who have donated towards server costs
KidChaos's Avatar
Join Date: Mar 2011
Location: NJ
Posts: 301
iTrader: (1)
Help Diagnosing where my exhaust leak is

OK, first off, sorry about the new thread for this topic, but I am so frustrated/stumped on this one.

I have an exhaust leak. This I am 99% sure of. Bike pops on decel, a lot. Like 5-6 times after I let off throttle. It happens more when the engine is warm (perhaps b/c the pipes are hot?)

I cannot determine where the leak is.

More Details:

Bike was completely stock when I got it. Popped like a popcorn machine - but nothing abnormal based on what I have read, reed valves were the culprit.
I coastered, popping mostly stopped. I De-goated, started popping like crazy on the right side, front cylinder.

I adjusted carb screws from factory setting to 2.5 turns, then out to 3 turns, and finally 3.5 turns, only minor affect in popping if any at all.

Couldn't get a good result from cigarette smoke test.

Thought I determined that it was the connection between the added pipe and the muffler. Tried sixteen ways from Sunday to repair that connection. Each time it seemed to stop popping briefly (5-10 minutes into ride it would start again) In retrospect maybe this was wishful thinking that I fixed the problem.

Got frustrated and decided to replace exhaust with V & H Cruzers since I wanted to get them eventually anyway. Used HD gaskets as recommended here. Either there were no stock gaskets in there in the first place or they had completely fused with the inside of the exhaust manifold, because I could not find anything resembling a crush gasket, or any loose parts for that matter between the manifold and the stock pipes anywhere. Seating of the new pipes seemed to go well.

For about 2-5 minutes of first test ride there was no popping, then it was back. Still no results from the smoke test. Played with air/mix screws and no major difference between settings from 1.5 turns all the way to 4 turns.

Now I am beginning to wonder if when I did the De-Goat perhaps I loosened or damaged the exhaust manifold or the exhaust manifold gasket while taking the muffler off for the first time. I remember I needed to do quite a bit of twisting and rocking to get it to break free. This does not appear to be in a very accessible location to get access to it.

How would I go about testing/removing this part to check. Do I need to do an engine pull? Does anyone have any suggestions on what might be the problem if it is not the exhaust manifold? Should I recheck the coasters, or perhaps put some RTV red silcone in them to ensure the leak is not there?

I thank you all in advance for your advice / comments

KidChaos is offline  
For the best viewing experience please update your browser to Google Chrome