Dunstall Megaphone muffler

[Ron C]

Anyone here use one of these mufflers?
Thanks Ron

[blethermaskite]

Yep! have used these many times over many years, in my opinion this is the best compromise 'silencer' I have found for a single, (better than a Conti !) have one on my widecase 350 mk 3. Cheers George

[Duccout]

I fitted one of these to my very first Ducati, a 350 Mark 111, back in 1975; I don't know if it helped performance, but to my teenage ears certainly sounded better than the 'wet-fart' Silentium.


Cheers,

Colin

[Ron C]

Thanks George!
My bikes only have Conti. This will be interesting.
I’ll get it on my 250
Safe travels everyone
Ron

[Bevel bob]

Back in 66 we fitted a special Vic Camp exhaust system to a Mach 1 . A swept back pipe and a gold star straight through type of silencer . Probably similar to that fitted to the BSA RGS 650 It sounded absolutely awsome exactly like a 350 Goldy and the exhaust pulses could be felt from 6 foot away. Not only that , it went like one, 9000 through the gears and pulled 8350 revs in the very high 5th gear, somewhere around 105 mph . It needed a Triumph Bonny or SS Norton to catch it up on the straights , they got left behind in the bends!. The downside was it needed "fetling" every week to maintain the performance, Valve clearances . valve seats ,engine bolts and timing (points) . It was a Camp set up bike for PR racing with a remote rubber mounted float chamber that eliminated vibration frothing and made all the difference to the carburation at max revs. My 66 MK 3 NC is set up the same . But i am not the same any more.

[blethermaskite]

Bob, It's now its now 55 years since I bought my first Ducati and 52 years since I bought my (then new) 350 mk3, within 2 weeks I had removed the Silentium silencer and the Dellorto VHB carb (an awful instrument!) I fitted a cheap megaphone 'silencer' and an Amal 32mm mk1 concentric and successfully completed the running in process. In this spec. I was getting around a true 95mph and was happy at that.....for a while......then came a 32mm gardner flat slide racing carb with an Amal 'matchbox' remote float chamber and a Ducati race spec reverse cone open megaphone exhaust, as the 74 350 mk3s came with a green and white cam and in this format I was getting a true 110mph with very dramatic acceleration in a now super impressive power band. Of course the bike was now the toy of a complete hooligan and the noise was antisocial (to say the least). I tried many different silencers but every one of them to varying degrees killed the engines performance......until I fitted the Dunstall decibel silencer which shut the noise down 'a bit' and only knocked off about 10 percent of engine power. Many years later I tried a Conti but the engine just would not run as strong on it as on the decibel.
Fast forward to the recent past, I ultimately replaced the 'Dunstall' with my own home made manual converted Yamaha exup valve race open megaphone and went back to a 32mm mk1 Amal concentric with an Amal velocity stack......worked really well...but the mad noise again! so back to a decibel silencer again......and that where I am today, so many years of experiment leads me to recommend the Dunstall decibel 'silencer' every time. I'm sure others may disagree this is just my experience
Cheers George

[Duccout]

Hi George,

My experience was the same as yours; Vic Camp was selling a 350 Mk3 that he had built for a customer who, for some reason, had decided he no longer wanted it. The bike was sprayed in the gold and red colour scheme of one of the early sports models and had clip-ons and rearsets and a 32mm Amal carb. I snapped it up and loved it, apart from the Silentium silencer which I replaced with a Dunstall Decibel.

I remember riding down to Dunstall's which was located in a place called Crabtree Manorway, in Kent, one Saturday morning to buy it. After fitting it I also added the obligatory velocity stack and a finned manifold. Strangely, I never thought to check what gearing the bike was on, nor considered changing it; maybe I was happy with it as it was. I only kept the bike for a few months before trading it in at Vic Camp's for a 750 Sport which I kept for 40 years. Memories.

Cheers,

Colin