Let's take the mystery out of these first gen exhaust collectors

[uncledj]

For anyone who followed the thread, my 87 was making some crazy exhaust noise that caused me to remove and inspect the collector, the mufflers and the pipes several times.

The issue was resolved when I replaced a seemingly healthy collector.

I took the problem collector and cut it apart to see what was inside and what caused the problem.

Lemme tell ya. A healthy collector would be very tough to get apart without destroying it.

Using a die grinder with a cutoff wheel, I first cut along the perimeter of the bottom side hoping to peel away the skin with no luck. I was trying not to destroy it in the process, so I flipped it over and cut around the perimeter of the top, and although I had to cut through some of the perforated interior screen, I was able to get it apart mostly intact.

This was only possible because of what ended up being the problem, which was that the two welds that hold the bottom panel to the one baffle on the inside were broken. This must have been causing the loud sound and the rattle that I had.

I ended up re-welding the perforated screen anywhere that it had been pulled out during dis assembly. I then drilled 4 holes in the bottom panel where it contacted the baffle so that I could weld the baffle back on once I put it back together. I then welded the bottom panel that I'd cut back in place, then put the top back on, held it in place with a C clamp and welded it back on. I then flipped it over and welded the baffle to the bottom panel through the holes I drilled earlier.

I think the takeaway is that if you are getting these crazy sounds, it'd be worth it to run 3 sheet metal screws through the bottom panel into the baffle, in line with the 2 existing spot welds, one in the middle, and one forward of the front weld and aft of the rear weld. If that cures the problem, you at least know what the problem is, and can opt to leave the screws in and see how long it lasts, or pull the collector, drill a few holes like I did and weld the baffle back to the bottom panel without taking the thing apart.

In any case, I've welded mine and would be comfortable putting back on the bike, expecting no further issues.

If anyone else has this problem and can get their collector to me, I'd be happy to weld the baffle back in for them. Should be pretty easy now that I know what to do.

[Barry.B]

I pulled all the pieces out of the collector , bike runs a little louder but no affect on engine . this was on 85 venture royal

 

Barry

[uncledj]

I got kinda lucky with where I made the second cut with this one. I really don't see how you could get it apart without ripping the perforated screens apart, unless you cut the top out just about exactly where I did, and then you'd still have to deal with the baffle welded to the bottom.

There's really nothing to them. I'm still amazed at how much it affected the sound of my bike. Sounded like a rattling exhaust leak.

[dingy]

Very helpful.

 

I am still surprised it was the collector after what we saw inside of yours with the firer optic camera. It looked good and seemed very solid.

 

Gary

[Evan]

Great write-up John. Thanks for taking the time to do this for us.

[pmelah]

:thumbsup2::happy65::clap2:

[KIC]

Thanks. The pictures sure help in understanding the issues with the collector.

[JoeKanuck]

I vote for sending this to the First Gen Tech Library.

[Freebird]

Done. Thanks for the suggestion.

[GaryZ]

I find it interesting that the rear cylinders enter the collector aimed at the front of the bike. This means the rear cylinder exhaust can impede the front cylinder exhaust flow, and the rear exhaust must do a 180 degree turn inside the collector to go out the mufflers.

 

It looks like a muffler shop could build a replacement with better flow . . .

[Bubber]

I believe the idea the idea was to have the two exhaust streams ram into each other causing turbulence to cancel each other out, plus the baffle to stir that whole mess up some more.

 

That's my story and I am sticking with it!

 

Steve

[uncledj]

The back pipes are also a lot shorter than the front, so maybe the way they enter the collector gives added restriction to help match the restriction from the longer front pipes....???...

[dingy]

I find it interesting that the rear cylinders enter the collector aimed at the front of the bike. This means the rear cylinder exhaust can impede the front cylinder exhaust flow, and the rear exhaust must do a 180 degree turn inside the collector to go out the mufflers.

 

It looks like a muffler shop could build a replacement with better flow . . .

 

Maybe a Marks collector ??

 

Gary

[GaryZ]

Maybe a Marks collector ??

 

Gary

 

The Mark's Collector is lovely . . . and way too much money

[GeorgeS]

I bought one 3 weeks ago, and installed it. It Fits, it works, and is very high quallity !. For the amount of welding skill required to build this item, and the fact that it fits perfectly, I would not consider it to be over priced.

( especially when you consider the OEM price )

 

Also, the sound is nearly exact same as stock. Well to my ears anyway.

[pmelah]

i got a buddy that runs a minekie shop i think im gonna give him a picture of that and have him build me one for my venture only sad part is hes gonna wanna ride it when hes done

[frankd]

Uncledj,

 

You may also want to beef up the welds that hold the mounting bracket to the chamber case. I've had the mounting bracket come loose on 2 different chambers on my 83. When I cut open my last noisy chamber (on the 89), I cut 3 sides of a rectangle out of the bottom and then carefully bent the 'rectangle' so that I could get the pieces of bracket out. 2 of the baffles in this chamber pieces completely broken off. Then a friend of mine welded it back together.

 

Frank D.

[dingy]

i got a buddy that runs a minekie shop i think im gonna give him a picture of that and have him build me one for my venture only sad part is hes gonna wanna ride it when hes done

 

I got a large ice cream cone that says if he builds it from a picture your vocabulary will significantly increase when you try to mount it up. By that I mean, it ain't gonna fit. Getting the Marks and/or a stock one on and sealed is an adventure. I am fairly certain Marks has a fixture to make these.

 

There are 8 mounting points on one of these that need to be at the right angle, size and location to fit.

 

The Marks is about $320, stainless steel and solid. Down side to it is it doesn't come with gaskets or clamps & the sides need buffed to look similar to chrome.

 

Gary