Modern Vespa

Okay, I looked in the manual, and nothing in there. Which way does the muffler gasket go on? I pulled my muffler off, and there was no gasket what so ever! Is that normal? I think it blew the gasket about 1,000 miles back or so

If you have a sleeve which has a solid metalic ( or graphite ) coating at one end my view would be that the woven end should be fitted inside the silencer after making sure that the split pipe end is spread enough so that no force is required.

Fit the graphite coated end facing forward so that the sleeve will hold together as you slide it on to the exhaust pipe. Use plenty of copper grease on all parts. This will help it bed together more easily and it will also help if you need to split the joint for tyre changes etc.

Regards Roadster

Just bought a non standard woven type seal off ebay that was advertised for the MP3 but it was not long enough to fully seal the slots so I had to seal them with an extra jubilee clip.
Make sure you get a genuine one although they are quite expensive in comparison.

Thank you both! I did spring for the original Piaggio gasket. Heinlein dropped off two Yamaha 5PX-14755-00 gaskets, which seem to be the same size as ours at less than half the price. I will take a picture of the both tomorrow and show you then side by side.

I put the Piaggio gasket in upside down, and I had to use some force to pull it out:9 So.... it is a little elongated. The Yamaha is on the left and the Piaggio is on the right.

Mesh goes into the silencer (muffler).

I really had to force and pound the muffler back on today. It's soooo sad to hear the sound of a now scooter again.

I just looked at the WIKI and it said to put the muffler gasket in with the mesh facing out towards the engine. People here are saying the mesh goes into the muffler. Oy Vey I'm confused.

I install them with the mesh out, so when you installing the muffler the sharp edges of the pipe are less likely to catch the graphite.

When I wrote the original Wiki article, I had only considered the 500 Master engines, as at that time the OEM 250/300 collars were still graphite all the way through - though they changed a few months afterwards. On the 500 it's easy to insert the collar with the mesh facing outwards - not so on the 250/300s for some reason. On these I insert the mesh into the silencer, with the graphite end facing out. This ensures that the end of the downpipe doesn't cut a ridge into the graphite, making full insertion difficult - it just squishes the mesh instead. Also it means that the collar can be 'hammered' into the silencer easily.

I'll alter the Wiki.

... Wiki annotated.

Just had another graphite ring blow out. Both times they cracked after riding through water. I'm tempted to use some muffler repair tape to build up the area in front of the graphite ring to protect it from getting wet and blowing out again. Does this sound reasonable?

[quote="Buckeye Marksman"]Just had another graphite ring blow out. Both times they cracked after riding through water. I'm tempted to use some muffler repair tape to build up the area in front of the graphite ring to protect it from getting wet and blowing out again. Does this sound reasonable?

[quote]

That's puzzling. I've been through several floods and even forded a stream without this happening. Once assembled very little of the collar should be exposed and it should all be clamped up tight. Are you sure that you are inserting it fully in to the silencer? I can only repeat my suggestion that you should use copious amounts of Coppa-slip or similar non-setting copper grease. Put the grease under the clamp and on the screw thread as well. It all helps get a snug fit for a given amount of torque on the clamp.

Thanks for the copper grease recommendation. New graphite ring is scheduled for delivery sometime next week.

I never have to replace that exhaust gasket.

just do a AK upgrade. its lighter and sounds better, easier to take off than stock when doing tires and servicing.

The first thing I did when I got my New 2016 Home from the Dealer was take that 80 pound weight off the bike for one of these. I love the sound as I don't have any DB Killers Installed, and no gasket to deal with...

https://scooterpartsco.com/piaggio-parts/piaggio-mp3-500-parts/leo-vince-sbk-nero-slip-on-for-piaggio-mp3-400-500?zenid=tkv5pfuahsqsve3u7u7mo1epf1

23,000 miles on my MP3, taken the muffler off three times I think (maybe four), and still on the original graphite gasket. Got a spare handy, though.

I forget which way I insert the gasket... I want to say I insert it into the muffler, but with the mesh facing out so as not to be damaged by the four wings of the muffler when it is compressed, and wiggles around. I guess I hadn't thought about the end of the downpipe digging in.

Still had original gasket after 4 tire changes and one brake change. I was the only one to remove the muffler, and was careful. I suspect that dealer mechanics could care less about the poor old gasket. Happy New Year everyone!

there seems to be several styles of gaskets that yamaha sold

this one seems like it would hold up the best. its made of copper. with what looks like asbestos for soft seal. cost to make them must have been higher.
2G2-14714-00

full graphite
3YF-14714-00
3YF-14714-00-00

Guarantee there is no asbestos if it is sold in the US.
You want the graphite bushing as it lets the pipe slide in and out.

you do understand what "looks like" means? maybe not.

whatever it is it is there so it can slide. and copper if far more durable and heat resistant to steel wire mesh.

so the more intelligent shoppers may see it as a better buy.

I'd not put a copper gasket in any of my scooters' exhaust slip joints.
So I guess I'm not so intelligent, huh?

There have been several reports on this forum of the downpipe cracking when a brass gasket has been used.

Graphite is a wonderful lubricant - that's why the joint can move even when firmly clamped up so no exhaust gas can escape.