Plugged Exhaust?

[GGely]

No worries! I’m going to send the camera in to entertain the grandson but I will pull the offending muffler, hopefully next week.

Stay tuned, there will be pictures... because...

 

[GGely]

Minor update (For Walleye!)...

After spending the day on phase 2 of our kitchen pantry renovation, late yesterday I went for a drive north of town, purely to warm the bike up and to see if the bike had the same issue fully warmed up and on the centrestand.

This is clearly a selfless act, meant to generate more content to inform and entertain the members of this forum. I would get no value at all from driving for a couple of hours on a cool fall late afternoon. Driving through the countryside, red, yellow and orange leaves everywhere.

And annoying road signs like this one:



Anyway, when I had a minute to pull over and check, I put her on the centre stand and... no change.

Nothing from the left pipe.

 

[GGely]

Wake up Walleye! UPDATE!!!

But nothing conclusive or remotely useful. The camera wasn't able to focus particularly well so there is no video. However, there was some minor progress because of the way I sent the camera into the muffler. The camera is about 1.25" long, attached to a 5 metre USB cable, so it tended to wander on the first couple of attempts. So clever me, I attached the camera to the end of a 6 foot glow rod (a fibreglass rod used in low voltage cabling) and down the muffler it went.

And stopped with a thunk just behind the rear bolt that secures the foot peg bracket. Tried it a few times and thunk it was. So I tried the right muffler and TWANG, it stopped behind the right side bolt. A much louder, brighter metallic sound. Back to the left side and thunk, it stopped. Dull, muted seemingly metallic sound.

As I slid the glow rod in, I could feel what seemed to be an opening in the bottom, after which the glow rod went a bit further and stopped. I am guessing (assuming, never...) that that opening leads to the lower section that I think (what, me assume?) leads to the inlet or engine side of the muffler. The idea there is that the muffler is indeed similar to the picture Andrew provided in post #14.



Next step, when the gaskets arrive, will be to pull the muffler.

Stay tuned!

 

[bdalameda]

I guess the question is - how does it run? I would assume if one muffler was plugged it would run poorly.

Still sounds like bad carb sync, but the St1100's do have both sides of the engine exhaust come into a single collector before splitting into the individual mufflers so I guess you could have a situation where the exhaust is taking the path of least resistance.

Does it idle smoothly??

 

[Roger]

I once saw a friend clean out his silencer (off the bike) using an oxy-acetylene blow-torch. Got the end red hot, then switched to oxygen and watched the red glow travel all the way through as the carbon burned away.

 

[GGely]

I guess the question is - how does it run? I would assume if one muffler was plugged it would run poorly.

Still sounds like bad carb sync, but the St1100's do have both sides of the engine exhaust come into a single collector before splitting into the individual mufflers so I guess you could have a situation where the exhaust is taking the path of least resistance.

Does it idle smoothly??

Somewhere above I note that it doesn’t seem to bother the bike at all, however the following are factors:

1. I’ve never heard one of these running in person and wav files don’t cut it
2. My last bike was a GL650 Interstate
3. I have no idea how this bike should run

I can tell you that with the exception of a bit of vibration (lol funny after the GL!) at about 4500 rpm, the bike pulls hard enough to scare the crap out of me. It idles as I would expect it to.

I am unconcerned about riding this bike anywhere but I guess that confidence could be misplaced. However, that’s what CAA exists!

 

[bdalameda]

Since the bike is new to you I would suggest that you find one of our members to take a look at your bike and ride it. They will know right away if everything is proper. A vibration in the 4K to 5K rpm range is a good indication of improper carb sync. The ST1100s are known to be smooth.

 

[GGely]

Regarding carb synch, as above, the Carbtune is out on loan and won't be back for a few weeks. The carbs were synched in June to within 3 or 4 cmHG on the Carbtune Pro and since then we've covered about 4,000km.

I was hoping to hook up with Michael in August to take her for a spin but haven't had the chance to get back into the city. If anyone is on a ride to the fall colours in the east and cna pop by for a coffee...

 

[GGely]

Ok, I borrowed back the Carbtune today and rechecked the synch. Here’s where I finished up after a few minutes:


Now, I should clarify that although I say there’s nothing coming from the left muffler, that’s a relative statement. There is a wee bit of exhaust coming out but it pales in comparison to the output of the right muffler.

Think a gentle touch from a sleeping puppy versus a hug from a full grown Irish wolfhound.

 

[GGely]

Ok, finally found some time to get back to this issue and...

First things first, after lots of Deep Creep, the clamp bolts came out pretty easily. Then the muffler rolled over and almost twisted out, all on its own. Yup, easy peasy.

Keep in mind the engine was swapped about 6,000 miles ago so although I didn’t think it would be welded in there, it did come out super easy. Which also makes sense if the muffler wasn‘t heating up to the correct temperature. The gasket was silver in colour on that outside edge. Not like the right side gasket, which is the dark black I expect.

So some thoughts:

1. There doesn‘t seem to be an obstruction in the muffler. I’ve blown air through both directions and it seems fine

2. is there a blockage in the header? Doesn’t seem to be. I was able to send a fish tape (gently) from the collector to the bend in the header

3. Didn’t see or feel a blockage in the header

4. Is it firing only on the 1 and 3 cylinders? Granted I’m coming from a twisted twin GL650 but it pulled hard, got good mileage and never complained. Temps were as expected

5. Could the timing belt challenge, which is on this thread, be contributing?

Any bright ideas out there?!

Thanks!

 

[GGely]

Update for the records. Had to pack some things to prepare for some work tomorrow and noticed a small shop vac sitting innocently in the corner. Hmmm...

Regarding point 1 above, I had tried to use my compressor to see how well air moved through the muffler. Maybe I didn’t have enough pressure.

What about the shop vac? After all, it could draw air through the muffler as well as push air through. Note that I haven’t lowered myself to the obvious crass expressions for this test. Not yet, anyway.

So I fired up the shop vac and tested drawing air from both the forward end of the muffler and the tail pipe. It was clear that something is holding things up, since the vac sounded like I had vacuumed up one of the dogs by the tail. Not good.

Then I tried pushing air both directions. Same result. A strained sound from the shop vac and not much air moved through the muffler.

Not willing to cut the exhaust system apart, I’m not sure how the two sets of headers connect through that centre box. Does it maintain a separation of the two exhaust flows from exhaust to muffler or are they combined in that chamber?

Here’s another thing I don’t know... how is the ST1100’s muffler built? Is it packed with all sorts of junk to impede my poor shop vac? Or is it a series of offset chambers which should pretty much allow a free flow of air from any direction? In which case I may have an entire family of mouse corpses inhabiting that muffler.

Good news is that I have a set of Delkevic mufflers that I can put on the ST and see if there is a difference.

Again, I look forward to any input!

 

[Walleye]

 

[GGely]

Sorry Walleye, can’t tell what those jugs contain!

 

[Walleye]

Sorry Walleye, can’t tell what those jugs contain!

sorry bad copy, thats professor amos super drain cleaner, wont harm pipes.

 

[GGely]

LOL, I knew it was something like that! Thanks!

 

[Andrew Shadow]

Here’s another thing I don’t know... how is the ST1100’s muffler built? Is it packed with all sorts of junk to impede my poor shop vac?

I cut one open. No filter or sound absorbing media such as the glass pack mufflers have. Only a series of off-set perforated tubes.

Edit:
Found my diagram of an ST1300 muffler. ST1100 is the same concept.

 

[GGely]

Interesting. The reduction in air pressure from the shop vac is quite significant.

So there must be a rodential (rodentary?) obstruction of some kind.

Thanks, Andrew!

 

[ST Gui]

Once you try to move enough air through the muffler there's going to be a noticeable reduction in output or it wouldn't be much of a muffler. Did you get any debris out? Other than carbon bits? Putting the shop vac exhaust to either end like you did should have shook some evidence of FOD or mouse occupancy out.

 

[John OoSTerhuis]

Did you do the um... er... job test on the other side for comparison?



John

 

[SMSW]

Not to hijack the thread, but my V Strom came w/ a titanium aftermarket exhaust that prevented mounting a center stand. The PO had sold me the bike with the OEM exhaust so I swapped the two systems. When I fired the bike up, a fountain of pink insulation arced through the air and out my garage door (the bike was facing inwards). The OEM system had been stored in his attic and when I looked at the driveway, there was a lot of black rice mixed in with the pink fluff.

I doubt you can run the bike without seeing something blasting out of the muffler if your problem is truly rodent caused. I would think it is more likely a clogged cat converter.