HELP - exhaust leak

[Guest Rev'n Ahead]

Hello everyone!

 

Our bike did not pass the safety test because of an exhaust leak... I took it apart, it was leaking BIG at the rear cylinders which I fixed with new seals and a good cleanup.

 

Then it was leaking at the 6 joints around the collector box... I tried the copper sleeves recommended on VR.org but couldn't get it to fit right so I went to our local Yammy dealer and bought the six OEM seals. It all fit so well together, but still leaks at the two joints at the front and the two heading out to the tail pipes. GRRRRRRRR I can't plate it and ride it if it ain't passed safety.

 

How can I seal these joints if a new seal isn't doing it? I've wire brushed the whole collector box and it looks real good. No leaks, no cracks, no black marks, I even painted it silver with high-heat paint so I could see if and where it's leaking... the box is not leaking. But the joints, with new seals is still leaking. HELP, please, please, please.

[frankd]

I've taken the exhaust system off of both of my Ventures many times, and I usually put them back together using the old gaskets, and nothing leaks. That makes me think you have another problem. Are you sure the exhaust clamps are tightening properly?? The clamps also have locating tabs, and these tabs have to be in the right spots for the clamps to tighten correctly. Check the bolts/nuts and make sure the threads are in good shape and not stopping the clamps from tightening. I've also had the exhaust chamber crack where the mounting bracket is welded and cause leakage.

 

You also mentioned the rear cylinder pipe gaskets. These have stops that prevent the clamps from being overtightened. THe problem with these is they bottom out too soom. Use a grinder and take off some of the stop so they tighten a little better. When my 83 was new, I had problems with these.

 

 

Frank D.

Edited May 1, 2012 by frankd

[Marcarl]

Are you sure it's leaking from between the joints and that there is not a hole in the collector? Also, there is a pin hole in the muffler, just behind the collector and it points down. These will show signs of 'leakage' but it is designed that way and is normal. Also, if you drill out the muffler it will give you a bit of a deeper sound, less back-pressure and so maybe solve the leakage problem.

[dingy]

See post 31 in thread below. There is info & pictures of a 700 deg RTV sealant that will work.

http://www.venturerider.org/forum/showthread.php?t=67487

Gary

[Guest Rev'n Ahead]

Are you sure it's leaking from between the joints and that there is not a hole in the collector? Also, there is a pin hole in the muffler, just behind the collector and it points down. These will show signs of 'leakage' but it is designed that way and is normal. Also, if you drill out the muffler it will give you a bit of a deeper sound, less back-pressure and so maybe solve the leakage problem.

 

 

What exactly do I drill out?

[Marcarl]

What exactly do I drill out?

If you look into the exhaust end of the muffler, you can see a small 'plate' in the middle. It takes about a 3\4" or 7\8" bit to clear this out. I started with a 7\16 twist drill and then finished the job with a 7\8" spade bit..... so much for the spade bit, but it worked. There is also one if you look at the inlet of the muffler, so if you want you can remove it as well, but now you might be running into more issues with carbs and noise.

[09RSTD]

When I installed the new slip-on muffs on the RSTD I used some exhuast wrap around the joint before installing the clamps. Seems to work great. Worth a shot if you have some exhaust wrap laying around.

[Guest Rev'n Ahead]

If you look into the exhaust end of the muffler, you can see a small 'plate' in the middle. It takes about a 3\4" or 7\8" bit to clear this out. I started with a 7\16 twist drill and then finished the job with a 7\8" spade bit..... so much for the spade bit, but it worked. There is also one if you look at the inlet of the muffler, so if you want you can remove it as well, but now you might be running into more issues with carbs and noise.

 

 

how far into the tube is the plate? I've heard from our local police force that they are now sticking a tape measure down the exhaust to make sure they are not drilled out... I'd guess that they would only do this to really loud bikes.

 

I'm thinking it will be a good idea to get the gasses out of there will as little restriction as possible. At idle it doesn't leak... only when I open the throttle a fair bit. So, looks like drilling out the lower end (exhaust end) might work well.

 

Gonna go try to drill it out and goop up the joints with muffler sealant which I bought from Cdn Tire.

 

I sure hope this works.

 

[Guest Rev'n Ahead]

Wednesday Morning Update:

 

I gooped up the 4 intake seals on the collector with some exhaust sealer (hi-temp caulking kind of stuff) and installed them carefully last night. After letting them sit for a bit, I turned on the bike, without accelerating, and held my hand on the front exhaust pipe until it got good and hot and then shut her down and let her sit overnight.

 

This morning I gooped up the two exhaust pipes and installed them, same way - heat it up a bit and let it sit.

 

Good News! The other seals were NOT leaking this morning... here's hoping... I'll be looking at this real carefully tonight after work - I'll let it heat up slowly, and then when she's hot, I'll crank on the revs and see if she has stopped smoking. I sure hope so!

 

BTW: Why would the two exhaust ports on the right bank (front and rear) NOT be getting as hot as quick as the two on the left side? Last night they got hot quickly - this morning it was cold for a long time, I touched the left front pipe and OUCH it was heating up good. I pulled the spark plug wire to see if the engine missed at all and could definitely hear a difference when taken off and then again when replaced. I assume they are firing... but the front and rear right pipes were much colder than the left... any ideas???

 

thanks everyone

[twigg]

Wednesday Morning Update:

 

I gooped up the 4 intake seals on the collector with some exhaust sealer (hi-temp caulking kind of stuff) and installed them carefully last night. After letting them sit for a bit, I turned on the bike, without accelerating, and held my hand on the front exhaust pipe until it got good and hot and then shut her down and let her sit overnight.

 

This morning I gooped up the two exhaust pipes and installed them, same way - heat it up a bit and let it sit.

 

Good News! The other seals were NOT leaking this morning... here's hoping... I'll be looking at this real carefully tonight after work - I'll let it heat up slowly, and then when she's hot, I'll crank on the revs and see if she has stopped smoking. I sure hope so!

 

BTW: Why would the two exhaust ports on the right bank (front and rear) NOT be getting as hot as quick as the two on the left side? Last night they got hot quickly - this morning it was cold for a long time, I touched the left front pipe and OUCH it was heating up good. I pulled the spark plug wire to see if the engine missed at all and could definitely hear a difference when taken off and then again when replaced. I assume they are firing... but the front and rear right pipes were much colder than the left... any ideas???

 

thanks everyone

 

You correctly identified an intermittent misfire.

 

If all 4 are firing correctly, the two at the front will heat up at the same rate, as will the two at the back. The rear will appear to heat faster because they are single wall tubes, and the front are double walled.

 

When mine did that it was caused by a blocked pilot jet.

[frankd]

Is there any chance that your carbs are out of sync?

[dingy]

Is there any chance that your carbs are out of sync?

 

I vote for carb sync also. This has a dramatic effect at idle on header temps.

 

This I know. Just fixed this a week ago on mine.

 

Gary