Bonneville America Forums Forums Technical Forums Exhaust This is driving me MAD

I am goin nutz here... Still fighting that !#$&%! Exhaust leak.

I put Bubs on WOW!

Replaced and sealed the crush washers, and reset the headers. Spent an eternity messing with the crossover junction.

Still each time I ride, when she gets warm I get the same exhaust leak and I can feel it in performance as soon as it happens. I cannot find it although it seems to be coming from the right side.

I have spayed WD40 in the carbs to try and make it smoke. Didn't smoke. Tried to feel around Bubs. Can't feel a leak. Headers do not show any signs of an area that has leaked.

I am Looney Tunes at this point... WHAT COULD IT BE

Run it a while. You'll get some black streaking on the chrome at the point of the leak if it's n the header/silencer joint or cross-over - At least I did. You may want to re-torque while hot, as well. Sometimes the heat will expand the bolts to the point they are loose. Sometimes that is exaggerated when dissimilar metals are concerned. I emphasize ’re-torque' you don't want to pull the threads out of your head or stretch any threads. That will complicate your riding time a whole lot more than the leak.

what is making you think you have an exhaust leak?? most mechanics have different "sniffer" tools that you can wave by the pipe and find a leak if applicable.
good luck

try folding up a towel and holding it tightly against the end of the muffler of the side that you think is the problem(while idling). The back pressure that you will create should let you identify the leak.

Post deleted by Grump

Thanks to all... As usual, excellent suggestions. I will try the towel trick. I am also going back to thinking I got a bum valve clearance job.

When she heats up, very noisey and perhaps was making me think the sound was a small e-leak.

Against my better judgement I am taking it back to the dealer for more personal abuse. You see they like to make you beg and kiss A$$ for bad service....

I use an automotive type stethoscope (sp) I bought off of a tool truck, just stick in your ears and move it around your connections and you will find it. A piece of heater hose can be used as well,(hold one end to your ear and move the other end around the suspect area) not quite as precise but it works.

Yo Beav, did you get this problem solved yet? Inquiring minds want to know!

I will know this week... Took my TBA to the Dealer Yikes!

Their mechanic told me he thought the automatic back tension adjuster for the timing chain was in between notches. Said he pushed on it with force and it clicked in. He felt it was quieter after that.

That very well could have been my excessive engine noise.

Also putting the Thruxton needles and dyno tuning. I will report when I get it back...

Thanks for checking

Make sure your spark plugs are tight. I once had a snowmobile (this is a little embarassing) that made a phfsst phfsst phfsst sound, and lost power when it got warm. I didn't figure out it was a loose plug until I burned up the head.

John

When I took my bike to the local dealer for a valve adjustment, I alter found out that they didn't even reset the cam tension. The dealer I bought the bike from, 120 miles away, showed me the cam tensioner problem when I took it in. After shimming the intakes to the tight side of spec, and the exhaust to the loose side, I noticed an increase in performance and better gas mileage.

To All,

Got my problem fixed. Must have been that automatic backtension adjuster. Anyway the clack clack noise is gone and I am a happy camper...

Interesting that the mechanic said, and showed me from the dyno, that the 160 mains were too rich. HP took a real dip around 5k (like it died off the charts). He put 140s in with flat results throughout the top end.
Still not sure about the Thruxton needles. Haven't been able to ride much since it is only in the low 60s here.