Track legal Hawkstone exhaust.

[Jerry]

I´m`in the process of refurbishing my 1962 24 MDS Hawkstone Special. To make the bike track legal I need a quieter exhaust system instead of the open megafon as fitted now.
Is it possible to buy an exhaust system `off the shelf´ or will I have to have one made specially.
Any help will be greatly appreciated.

[ADickerson]

Hi Jerry, I'm not aware of any off the shelf systems readily available for your MDS today, although the Mayfield units were available until a few years ago. I suspect most systems in use today have been fabricated together individually, some utilising pieces scavenged from more modern machines to make things a little easier. Also, I don't know what regulations regarding silencing exist where you are! Over here the rules simply state that machines must have a silencer fitted, with no specific noise level stated or being recommended. Most people tend to fit a muffler on the end of the expansion chamber to dull the ear piercing noises and most are reduced to an acceptable decibel level this way. Naturally the quieter the machine is, then the less likelyhood there is of it being deemed too loud on tracks where noise might be an issue!
Not much help I'm afraid, let's hope someone else is better informed and prepared to add a more positive response.

[Colin Sparrow]

I´m`in the process of refurbishing my 1962 24 MDS Hawkstone Special.

The 24MDS was the "Moto Cross Special". A '62 Hawkstone Special would be a 24SC or just possibly (for '62) a 24MD. Pedantic I know...

[Jerry]

Ok Colin, got me there.

The request is the same but the bike is different. Instead of a Hawkstone it´s a 24MDS Moto Cross Special.
Any help would be welcome.

[johnrunnacles]

I'm with Adrian's response, Jerry. There are probably a dozen or more MDS's participating from time to time in the Greeves Championship and I think it is fair to say that no two have a similar pattern of exhaust. Similarly with the earlier MCS's and the iron-barreled Hawkstones. Mind you, Terry Sewell (TDS Services) was offering a prefabricated system a few years back, so it may be worth your while asking about his source of supply. Will send you his email address on a Private Message.
Best of luck.
John R

[Jerry]

Ok. Thanks I´ll check him out.

[stormer254]

AJS of Andover sell a kit with which you can make an expansion chamber and then fit one of their Stealth silencers. Ring them up and ask to speak to Nick Brown.

[mudmonkey]

AJS of Andover sell a kit with which you can make an expansion chamber and then fit one of their Stealth silencers. Ring them up and ask to speak to Nick Brown.

the stealth silencer in no longer available and the 'cones' are for a 370 ajs, that spec engine is very different from a mds......port timing, duration, tuned length are very different....


i can make a 'bespoke' performance chamber if you are interested ?...given enough engine details..... i can fabricate a cone expansion chamber....from scratch

[Jerry]

Ok. that sounds great.

Firstly just three questions :

1. Are we talking about a full exhaust system or just the expansion chamber ?

2. What engine details will you need ?

3. How much will it cost ?

[Gr11mpy]

MDS Expansion Chamber

Ugly and offensive to the purists but works exceedingly well with the MDS motor.
Modified Honda CR250 pipe with home made silencer......

Going to try a underslung aftermarket pipe from a '74 Ossa Phantom later in the year, time permitting. Looks loads better and more in keeping.....

[stormer254]

If you can make them fit most twinshock and early Evo exhausts will work well

[blackshiver]

Good Heavens - that makes a 1960 Greeves Megaphone look like a minimalist work of art.

[Colin Sparrow]

Good Heavens - that makes a 1960 Greeves Megaphone look like a minimalist work of art.

Which, of course, is exactly what it is!

[stormer254]

Which, of course, is exactly what it is!

But the noise was great in more ways than one