Exhaust won't go on

Colin ST · Jul 8, 2017

My 1995 ST1100 has 125,000 km on it and the exhaust was rotten so I bought another one from a fellow who installed a Delkevic full system. I saw it on his ST in his garage.

The downpipes and collector on his OEM unit I bought look fine - virtually zero rust - but the assembly just will not go on my ST.

My bike is on its side stand. The replacement RH exhaust pipe is still connected to the left hand pipe & collector box and it appears not to have rotated at all. When I try to install it on my bike the left and right sections seem to be a little too close together but when I try to splay them apart it won't rotate. I suppose if I heated it or something I could get it to move but if it was sold to me in the same condition as when it was removed from his bike I shouldn't need to.

Has anyone experienced the same problem? Any ideas?

dwalby · Jul 8, 2017

Never had to do that job, but I think there's a junction band that joins the two sides together that you need to loosen. Did you loosen the bolt on that band? Maybe hit it with a little penetrating oil if its really stubborn, but not too much or you'll get smoked out when it heats up the first time.

edit: here's a couple pages from the service manual that might help.

Colin ST · Jul 9, 2017

dwalby said:
Never had to do that job, but I think there's a junction band that joins the two sides together that you need to loosen. Did you loosen the bolt on that band? Maybe hit it with a little penetrating oil if its really stubborn, but not too much or you'll get smoked out when it heats up the first time.

edit: here's a couple pages from the service manual that might help.

Thanks for the tip but yes, I loosened the band clamp that joins them together. Also thanks for the service manual pages but I already have it.

Colin ST · Jul 9, 2017

Karen said:
Why is the right exhaust pipe connected to the left side?

What year is the donor exhaust coming from.

I found a difference between pipe diameters when trying to put a 1994 OEM exhaust onto a 1993. I had to change out more parts than I expected to because of it.

https://www.st-owners.com/forums/showthread.php?123897-Exhaust-header-replacement&highlight=

I might have not been clear but the right exhaust pipe connects to the left pipe / collector box.

Not sure of the year of the donor bike. I'm trying to get hold of the owner.

Thanks for the info on pipe diameters; interesting how it changed from one year to the next. Pipe diameters aren't an issue with me but overall dimensions could be my problem if they changed from the donor's model year to mine.

Here's where I vent about Honda. We wouldn't even be talking about this if this esteemed manufacturer had done the right thing and made the whole exhaust system out of stainless steel. Why in God's name did they make the downpipes stainless and then cheap out on the collector box and feeder pipes with rustable carbon steel? What was the thinking behind this ridiculous hybrid? It truly boggles the mind ...

Colin ST · Jul 9, 2017

Well it took a lot of jiggling and fiddling and pushing and pulling but after a couple of hours of work I finally got it on and loosely screwed on the eight nuts onto the eight exhaust studs. Then, when I checked the rear to see about the supporting center flange bolt that goes through the silencing rubber I realized to my horror that with the bike on its side stand, the center stand won't deploy and the aft part of the collector unit won't lift up far enough for the flange bolt to reach the captive nut on the frame.

That meant I had to drop the downpipe assembly, put the bike on its center stand and do it all over again. So, a bunch more pulling and fiddling and I did it. I loosely screwed the eight nuts onto the eight studs. Then when I went to secure the center flange bolt at the rear I discovered it won't line up exactly with the captive nut on the frame. It's shy of the hole by only about 2 mm but that's all it takes for it to not fit.

I REALLY don't want to drop the downpipes again to figure out a solution so I'm just going to pack it in for the time being and do something else -- like ride my HawkGT.

Lord, why me ...?

jfheath · Jul 9, 2017

I had a similar sounding problem installing a non-OEM system. Motad. The collector box arrangement is different but it took a lot of fiddling around to get everything lined up.

I documented it here (Link). Its not the same arrangement as the OEM, but I guess the problems are similar. At the very least you'll know that you're not the only one to have had problems and there maybe something in there that works for your little headache.

ST Gui · Jul 9, 2017

Karen said:
Sometimes walking away and trying again with a fresh perspective is all that is needed. Enjoy your ride.

+1 And the HawkGT is a fun distraction. Just don't stay away from the task so long that you forget what's what. DAMHIKT.

Colin ST · Jul 9, 2017

Colin ST said:
Well it took a lot of jiggling and fiddling and pushing and pulling but after a couple of hours of work I finally got it on and loosely screwed on the eight nuts onto the eight exhaust studs. Then, when I checked the rear to see about the supporting center flange bolt that goes through the silencing rubber I realized to my horror that with the bike on its side stand, the center stand won't deploy and the aft part of the collector unit won't lift up far enough for the flange bolt to reach the captive nut on the frame.

That meant I had to drop the downpipe assembly, put the bike on its center stand and do it all over again. So, a bunch more pulling and fiddling and I did it. I loosely screwed the eight nuts onto the eight studs. Then when I went to secure the center flange bolt at the rear I discovered it won't line up exactly with the captive nut on the frame. It's shy of the hole by only about 2 mm but that's all it takes for it to not fit.

I REALLY don't want to drop the downpipes again to figure out a solution so I'm just going to pack it in for the time being and do something else -- like ride my HawkGT.

Lord, why me ...?

OK so I solved the problem with a bit of creative maintenance. I knew I needed to move the downpipe / collector box assembly to the front a couple of mm but I didn't want to drop it down completely because it's such a hassle to maneuver it back into position. So I secured the pipes to their installed location with bungee cords that held them in place but allowed for a bit of movement.

Then off came the exhaust header nuts. With the assembly loose, I pushed it forward just enough to allow the flange bolt to be inserted through the silencer rubber on the frame and into the captive nut on the pipe (not on the frame, as I said above - my bad).

Once the center flange bolt was in place I went back to the motor and found that I had moved the assembly so little that the pipe flanges easily mated back up to the head studs. Problem solved.

The rest is just plain fun - torque the head nuts, bolt on the heat shields, install the mufflers and secure the tupperware.

Still on the subject of fun, I also bled the clutch and changed the coolant.

Thanks to all for your help!

tommyteabag · Oct 11, 2017

I got a complete exhaust system from delkavic and found the central hangar was about 3/4 inch short and the centre stand needed altering slightly before everything fitted.

Exhaust won't go on

Colin ST

dwalby

Colin ST

Colin ST

Colin ST

jfheath

John Heath

ST Gui

240Robert

Colin ST

tommyteabag