Das MZ Forum für MZ Fahrer

When I found my SilverStar 500 it had a Harley muffler welded to the original exhaust pipe, picture below. I have found a new MZ 500 pipe and Sebring A2 muffler. Stamped on the muffler is MZ 500, A2, e1, 0274. I want to return the MZ to original. I have searched this great forum and found that there were three mufflers available for the 500s; the A, A1, and A2. I try to translate but it seems the A2 is the best and least restrictive?

My bike is running fine now with the Harley exhaust. Do you think the A2 muffler will gine me more performance (or less), and will I have to change the setup on my Bing 64/33/306 carburetor? The setup is all original now, except for the float needle in the #4 position. Danke, Donny

The A2-Exhaust is the best one for the Rotax-MZ, afaik. Only the Tuning-Exhaust from EGU might be better.
If you take the A2, you should put the carburetor needle to the second snick from below (Dellorto)and there are some threads in the forum about air-tuning. Bing is not my cup of tea and i dont know how to set up.
There are some more Exhausts wich are good to drive but i dont believe that your Harleyexhaust is one of them. I looks too short, but you should try. Most People were suprised after the change. I changed from A to a half-self-maded Honda-CBR-Exhaust and the performancethrust was amazing.

Sorry 4 my english, and thanks to google-translate :>

Danke Pitu - I understand perfectly. The A2 Sebring is new, but I will need the header pipe rechromed first before install. After install I can play with the Bing. I hope someone here has the A2 and the Bing now and can tell me the best setup for the carburetor.

Also, what are the actual differences between say the "A" muffler and the "A2"? Is it more free-flowing? Louder than the "A"? The Harley muffler is quite loud. Thanks!

Hello,

yes, the Sebring A2 is the best "legal (in Germany)" Exhaust you can find for the MZ Rotax!

But if you can test other ones... test it.

The A2 is a little bit louder and longer.

If you want more power you can put a 36mm PHF Dellorto and a 805 camshaft on your Silverstar.

Or you look for the engines from RonWood


Bye

simmetuner

Thank you for the information simmetuner. I have talked to the Ron Woods people looking for one of their exhaust systems but they are no more. There are a couple of ex-Ron Woods dirt track racing bikes here in Alabama and I got a chance to see them. But of course the owner will not sell.

I knew about the Dellorto, but not the 805 cam. I have a couple of spare engines here I'm going to build up over the winter. But for now I'll install the A2 system tomorrow and see if it's better than the Harley. I think it will be much better. Here in Alabama we do not worry about "legal" MZ's as the police have never seen one before and there are no inspections. Danke.

Ron Wood F 800 Rotax dirt tracker. I want.

Hello Donny,
the A2 is the best, compared to the A and the A1. It´s the biggest of them in length and diameter (as far as I know). It´s also most difficult to find.
Best regards, Martin.

Martin H. hat geschrieben:Hello Donny,
the A2 is the best, compared to the A and the A1. It´s the biggest of them in length and diameter (as far as I know). It´s also most difficult to find.
Best regards, Martin.

Thanks Martin. It is also very heavy. It weighs about three times more than the Harley muffler. I got this when I went to Miami last week for parts. When I saw the A2 stamped on it I remembered reading about it here in the Rotax section of Das MZ Forum and was happy. This is the best MZ forum. All of you have helped me very much to learn about my SilverStar. I just wish I could speak German so I could translate the information better.

The best Exhaust for a Country might be........

Donny hat geschrieben:Ron Wood F 800 Rotax dirt tracker. I want.

What a beauty!

Alfred hat geschrieben: What a beauty! : Love:

Me too Alfred. That's the exhaust I want.

I got the A2 Sebring and header pipe on today, then it would not start! After playing with it for about one hour I found the sidestand switch was not making contact. I bypassed that and it started right up. It is much quieter than the Harley muffler, but it's snowing and late so I could not take it for a ride. Maybe tomorrow.

Here's another street legal ex flat tracker w. the Rotax 504E from California:

Nice day today so I went for a drive today with the new A2. It seems to pull much better over the entire power band from low to high and is much smoother at 5000-6000 RPM. What I really like though is how quiet it is compared to the Harley muffler. The Harley barks like a dog under wide open throttle and at idle you really know it's a single thumper motorad. I used to like loud machines in my younger days but no more. I have set the idle at about 1100 RPM. It also seems to warm up much faster than before. From cold start to running smooth with out stumbling in a minute. Very nice muffler.

simmetuner hat geschrieben:Hello,
If you want more power you can put a 36mm PHF Dellorto and a 805 camshaft on your Silverstar. Or you look for the engines from RonWood simmetuner

Hallo;

I have located a Rotax 805 (and also 670, 675, 850) camshaft. I know the lift and degree of duration for all of them (the 805 is 9.6 lift and 248 degree duration for example) but do not know the specifications of the original factory camshaft. Do any of you learned MZ gentlemen know the specifications of the factory cam? I wish I could post this in German and hope you understand what I am asking. Danke, Donny

Donny hat geschrieben:I have located a Rotax 805 (and also 670, 675, 850) camshaft. I know the lift and degree of duration for all of them (the 805 is 9.6 lift and 248 degree duration for example) but do not know the specifications of the original factory camshaft. Do any of you learned MZ gentlemen know the specifications of the factory cam? I wish I could post this in German and hope you understand what I am asking. Danke, Donny

Hello Donny,
originally, it´s 225°; I found this here -> http://www.miraculis.de -> MZ -> Bücher -> "Reparaturanleitung MZ 500R - Motor".
I didn´t find the specification of the original camshaft, but it was mentioned here in the Forum some time ago.
Martin.

Donny hat geschrieben:

simmetuner hat geschrieben:Hello,
If you want more power you can put a 36mm PHF Dellorto and a 805 camshaft on your Silverstar. Or you look for the engines from RonWood simmetuner

Hallo;

I have located a Rotax 805 (and also 670, 675, 850) camshaft. I know the lift and degree of duration for all of them (the 805 is 9.6 lift and 248 degree duration for example) but do not know the specifications of the original factory camshaft. Do any of you learned MZ gentlemen know the specifications of the factory cam? I wish I could post this in German and hope you understand what I am asking. Danke, Donny

Hi Donny,

one user here queried ROTAX about this a while ago and subsequently (Dec 8 2007, if i noted this down correctly ) posted the answer and list of camshafts he received. I'll just shortly repeat the information
for the 504 E used by MZ:

The 504E/27HP came with 660 camshaft (237660, 225°, listed for 348GS and 506 Regolarita):
- outlet opens 36,5° BBDC, closes 8,5° ATDC, stroke 5,82 (valve stroke 7,9)
- inlet opens 3,5° ATDC, closes 48,5° ABDC, stroke 5,82 (v.stroke 7,9)
(this are the timings for the 506 Regolarita, the timings for 348 GS are all shifted by 6°. The 504E
presumably resembles the 506, not the 348)

The 504E/34HP's camshaft was marked 660* and is identical to the 800 and its replacement 801
(237800/237801, 249°, listed for 506-560):
- outlet opens 55° BBDC, closes 14° ATDC, stroke 6,87 (v.stroke 9,3)
- inlet opens 12° BTDC, closes 57° ABDC, stroke 6,87 (v.stroke 9,3)
(the 800 and 801 must be identical at least in these values)

The 805 seems to be pretty similar to the 801, the 850 was not in the list. Beware of the 675/860/865
camshafts, the combustion chamber won't remain collision free with these!

kind regards

Thank you Peter - great information, especially the v.stroke data. Looks like the 800 or 801 cam might be the best for a conservative conservative upgrade.