Fancy a reverse cone mega!

[billdn]

At the risk of upsetting some people I want to fit a a mega exhaust , having purchased one from Modern motorcycle company - it arrived and build wise looks good BUT it doesn't seem to fit over the muffler gasket. The outside diameter of the muffler gasket from CSMNL is 49mm , I've read other threads where tit may be necessary to adjust the final fit!
Am i correct that the muffler from the collector box goes over the collector box outlet but inside the silencer - in which case I'd need a 49mm silencer opening which doesn't seem available.
If I adjust the gasket it will be so thin as to be of no use and would probable break, the internal diameter of the silencer is 46mm, is there an alternative to the gasket ?

[Bryanj]

Not officially, but you could try exhaust bandage

[bobv7]

 You haven't said what the diameter of the collector box exit pipe is. If your new silencer will fit tightly over it then use exhaust sealing paste and a clamp.

[Athame57]

, I've read other threads where tit may be necessary to adjust the final fit!

What on earth can boobs and baffles have in common? 

[billdn]

Bryanj - thanks for that, I'll look into that.

bobv7 - that's just it the silencer is too small to go over the collector box outlet  - the outlet diameter is 47mm, so the silencer is fitting inside of instead on top - but the largest I've seen all seem to be 45mm!

Athame57 - oops, for got to proof read fist post , first post 

[K2-K6]

Something like this may be able to be incorporated into your system to neatly adapt it

https://www.ebay.co.uk/itm/Stainless-Steel-Exhaust-Adaptor-Reducer-Joining-Sleeve-Any-Size-Pipe-Swaged-Ends-/320502908018?_trksid=p2385738.m4383.l4275.c10

Conventional to always step "into" each successive section with exhaust flow,  so one outside existing collector to inside of new silencer could be done and almost invisible once fitted, just two external clamps to fit.

[ka-ja]

I have a reverse cone mega on my Yoshi, I used one of the exhaust reducers (above) welded into my laser pipe end, looks fine, will try for a photo later when I am fully awake.

[taysidedragon]

They do exist. I have a short mega on my 400 fitted over the collector outlet.
The silencer inlet is 49 or 50 mm. I made a shim and used exhaust paste to fill the gap then a clamp over the top. I got the silencer at Stafford Classic Bike Show a few years ago from a stand that sold universal and British exhausts. Try Armours and other Brit exhaust suppliers.

[billdn]

bobv7 - apologies the silencer DOES slide over the collector box outlet not inside- you were right- senior moment there!
So been busy with the Vernier this morning and here are the scores on the doors:-

Silencer/exhaust - outside dia. =47mm inside dia. = 45mm
Muffler/collar/gasket- outside dia. 49.2mm , inside dia.= 43.16mm
Collector box - outside dia. 42mm, inside dia.= 39mm

So obviously the gasket will not fit over the silencer , however without the gasket the exhaust will fit albeit with some small gap about 5mm difference overall which I make about 2.5mm around when measuring radius.
 Liking Tayside Dragon's thought, maybe not a bush but perhaps cork gasket wrapped around and then apply exhaust paste? Would cork withstand heat? Making a bush is beyond my skills + no lathe, or exhaust tape as bryanj suggests around collector box end, slide over silencer and fill remaining gaps with exhaust paste.
Thanks for all your thoughts gentlemen!

[taysidedragon]

I made the shim from thin steel sheet and wrapped it around the pipe. The exhaust paste and clamp seal it up nicely.

[K2-K6]

If you can centre the outer over the inner, then you could squeeze "instant gasket" silicone sealant into to gap in it's entirety.

This should mould you a bespoke fit spacer/seal to leave until set,  then use the clamp to secure.  It's heat resistant even at exhaust temperatures and should make a durable solution.

[ka-ja]

Here we go

[Tomb]

Any silicon mastic will do on exhausts, we use it on a Turbo Nitrous race bike without problems, where we need to guarantee no exhaust leaks to maintain boost. But as said, minimise the gap with a spacer, a hand rolled piece of sheet metal will do as long as you are clamping down onto it with the exhaust clamp, the silicon will work.

[billdn]

KaJa - nice looking job there! Think I have same silencer.
And thanks all for the advice,  sheet metal and silicone gasket on order as we speak.
Nice to be able to get help from you guys as ever.!

[ka-ja]

billdn-the reverse cone came with a set of thin steel adapter shims for different diameter exhaust pipes, it was originally intended for old British metal, my intentions were to make the collector box outlet such an diameter that I could fit various silencers for help carb. tuning my Amals.