Exhaust can for Qingqi QM200GY (aka Qlink, etc)

[forchetto]

Cheers Forchetto,
Just a question, why did you use such a huge silentbloc when those are available much smaller?

Couple of reasons:

I think this is the smallest size with an M8 male thread on it. This means that it screws straight on to the welded-on nut on the existing exhaust mounting point. The strap that comes with the can also has a slotted hole suitable for an M8 bolt.

I've got a box full of them left over from my kit-car building days. Had to mount lots of things flexibly to stop them dropping to bits.

You can't see it once the side cover is on.

Something I've forgotten to add to the instructions is to relax the exhaust system before finally bolting on the can. Just loosen off the exhaust port bolts so the pipe moves a bit, fit the can mounting bolt and once everything is in place and aligned tighten everything starting from the cylinder head exhaust pipe bolts and finishing on the can bolt. This is to avoid straining the pipe.

Note that on the last of the photos my pipe clamp is held with nuts on fixed studs. I've changed the original method of mounting from bolts screwed directly on to the cylinder head alloy to stainless steel studs with nuts and lock washer. No particular reason, it's just that I prefer it that way. All my previous bikes have had studs and nuts rather than bolts for that aplication. If the pipe bolts ever loosen they can wreck the alloy threads. The studs are locktited in and won't move.

[Moi34]

Did you try to attach the can using the original antivibration mount? Did it work or not at all?

[forchetto]

Thought about it and it can be done. The only thing is that the "top hat" shaped rubber thing is too big for the fixing hole in the strap supplied so it would have had to be re-drilled or filed. Stainless steel is tough though and not easy to work.



The hole in the strap would have to be made as big as the hole you can see in the original can, right hand hole. It would also weaken the strap by removing too much metal:



You could just use the bolt and flat washer only and fix the can solidly to the frame, you will get a bit of vibration transmitted by the exhaust. On the original only one bolt had an anti-vibration mount, the other being solid to the frame. I thought this was a bit silly. The idea of one of those mountings is to allow flex and "give" but the original can felt solidly mounted due to the aforementioned solid bolt fixing.

[Moi34]

OK I understood, it means that the 4th piece from the right has to go through the hole of the original can. To be efficient a similar mounting has to be done. Found a M8 silentbloc (the left one) quite similar to yours but don't have any ideas about the sizes.


This will do it I guess.

For the clamp I found that.


I was wondering whether the original clamp would fit or not?

[forchetto]

Here's a site detailing the types of rubber mountings available, clicking on each one shows what sizes are available:

http://www.ferrirubber.com/Ferri%20R...uffers%20A.htm

It's probably best to go with the narrowest "H" dimension to avoid the can being pushed out too much, consistent with M8 threads for convenience in matching the bike's thread and the hole in the mounting strap supplied with the can:



The original clamp that comes with the factory exhaust can be used. The one shown is really a hose clamp and not strong enough. I just went for a stainless steel pipe clamp because we work near an engineering parts supplier that has all this bit in stock and was convenient.
I also have a fetish for stainless steel....love the material, bright, ever-lasting and needs no finish applied to keep it looking good.

[Moi34]

Just a final stupid question to ask you Forchetto about this muffler that I ordered last week. Is it really necessary to cut the muffler pipe? I know that it makes sense to do it because of the clamp but I've seen some slip on exhausts using the same kind of clamp for attachment to the exhaust collector which are not cut for example CRD slip on exhausts. It's just that I only have a manual saw to cut it...

[forchetto]

Not at all. It's just that I'm a bit old-fashioned... the joint fits really tightly on mine without any clamp. Just push on and twist the can until it touches the welded ring on the pipe or near it. If it doesn't go on easily clean up the surfaces with emery cloth or a small grinder like a Dremel, etc.

One of our posters used silencer sealing compound to ensure a gas-tight seal but seeing how tight mine fitted it won't be neccessary.

[Moi34]

In this case no need for a clamp or just for style?

[forchetto]

If you remove the cans spring loop, which looks bad, and then polish the welding spots to a shine like the rest of the can, it looks really good. As I've said, I'm a little old-fashioned and feel better with a clamp.

[Moi34]

Hi Fochetto,

Received the can few days ago and even using a smaller silent-bloc will have to cut the plastic side panel as you did. Was going to do so but wasn't happy with it since an extension between the can and the collector should prevent this. Went back to Xian's Racer web site and found some down pipes for chinese scooters on which our can sould potentialy fit. Could cut one of these to obtain the desired extension don't you think? The first model will be better I think.