TOPIC:

Today's subject of consternation is the exhaust pipes. I haven't yet TIGged up a stainless exhaust, but I have to get the headers in place before I test-fire the engine. Well, and it's good practice to test-fit everything.

So, first general question:

Why is there a big window on pipe #4 that's cast into the cylinder block? Is this anything that merits concern? Is it there just to provide clearance for the cooling system components?



Second, and more important:

Pipe #5 rattles loosely. I don't know why. The distance from the flange to the base measures 9mm, just the same as its neighbor #4 (which is tight).

I'm installing the pipe with the same copper exhaust gasket that I'm using on all of the others, which are all tight. I'm also using the same split collars as on all the others, and tightening the keeper the same.

So what gives? Why do I have about 1mm of free play? I've tried swapping gaskets, keepers, and collars but to no avail: #5 wants to rattle. Do I need to double-up on the exhaust gasket? That seems counterintuitive: The nuts thread onto the studs just like all the others, and I simply don't know why it's rattling. The measurements all appear the same.



Any thoughts on what I'm doing wrong here? It's been two years since I removed the exhaust system, so I don't recall if there was anything hinky about that one particular pipe or the configuration of the keepers.

I had the exact opposite problem with my new DG. One pipe wouldn't go in the hole far enough to get the bolts started. Had to gently grind the edge to get it to fit. It wasn't the depth, there was a tiny burr along the side which prevented it from being pushed all the way in.

Can you swap the downpipes? Maybe it will tell you if its the hole or the pipe.

The issue you have is the exhaust and not the bike.

I have never heard of or had that issue with any standard exhaust or any other after-market exhaust either.

Never fitted a D&G so can only think that is where the issue lies.

Pete F
UK

Yeah, the exhaust has to be the issue. It's just not immediately visible what's going on.

I'll swap around components until I find what's at fault, and then break out the calipers. However, I don't know if that'll happen this weekend; we're having a heat wave in Phoenix, and it's supposed to get up to (potentially) 123F by Monday and I may just skip town and head for cooler climes for a weekend.

Never seen that before ! although I recently had some replica pipes that needed a bit shaving off to achieve a tight seat at the collar.

Re your heat wave: you could always come to the UK, we've had almost a week of constant cloud, rain and drizzle: and it is presently a balmy 58F.

Joking aside, 3-4 years ago I was awaiting a flight out of Sky Harbor Airport (think that was in June),and there was an annoucement stating if it got any hotter than the then 121F, all flights would be cancelled due to the air density being too thin to achieve sufficient lift. I have had flights cancelled due to snow, but that was a new one on me

To answer your first question- that's a leftover from milling the cooling system opening in the head. Check the hole directly above it, and you can see the edges line up.

As for your second question- yup, definitely the exhaust. If you welding up a new one, now would be a great time to fix it. If not, and it were me personally, I would just double up on an exhaust gasket until you get enough thickness to tighten everything up.

The purists will likely have a field day with this advice, but it wouldn't be the first time multiple exhaust gaskets ended up on the same hole....