Tuning piston for ETZ 250

[MZ_Max]

Hi,

I'm trying to find a piston that is more suitable for tuning, than the ETZ 250 original heavy piston with three rings. Has anybody an idea where I could find such? Googling doesn't help.

[DrGonzo]

I know very little about these bikes but did stumble across an MZ racing guide that mentioned using a Suzuki RM250 piston.
http://www.szocimotoros.hu/download/mztuning.pdf

[MZ_Max]

Thanks for the comment. I had already seen the MZ Racing preparation guide and also checked the Suzuki TS250 piston. The problem with it is, that both the crown and skirt are shorter than on MZ pistons. This would require change of the barrel height and also adjustment of the port positions. In my case this is a bit more than I'm prepared to do at the moment. I have found out that some Saab two stroke cars have pistons that are very close, when it comes to height and diameter measures, so I'll try to check them more closely and maybe then buy one. If that would not work for me, I'd test with an MZ ETZ piston to get the engine running at least. If more tuning would be required, then more drastic barrel changes could be considered. The bike is in pieces and has been so quite some time and also other parts are still missing, so I think it would give more satisfaction to get the bike ready and running and in the next phase put more effort on optimization of the performance.

[DrGonzo]

Sounds like a cool project man. Please keep us updated as you progress.

[vicar]

the ETZ is good for 80mph as std I just made mine look faster...I have a Taiwanese piston still with three rings but the top haven't come off yet despite repeated 8000 rpm forays in the lower gears

[Kev c]

Thanks for the comment. I had already seen the MZ Racing preparation guide and also checked the Suzuki TS250 piston. The problem with it is, that both the crown and skirt are shorter than on MZ pistons. This would require change of the barrel height and also adjustment of the port positions. In my case this is a bit more than I'm prepared to do at the moment. I have found out that some Saab two stroke cars have pistons that are very close, when it comes to height and diameter measures, so I'll try to check them more closely and maybe then buy one. If that would not work for me, I'd test with an MZ ETZ piston to get the engine running at least. If more tuning would be required, then more drastic barrel changes could be considered. The bike is in pieces and has been so quite some time and also other parts are still missing, so I think it would give more satisfaction to get the bike ready and running and in the next phase put more effort on optimization of the performance.

A car piston will be heavy as well, there are other bike pistons you could use and if you get a spare cylinder could have it machined easily, more power through out the Rev range and much more reliable.
Three ring pistons are not necessary and single ring Pistons are not suitable for the road

[burudi]

http://www.fischer-fahrzeugtechnik.de/

http://www.kolben-shop.de/Oldtimer---Yo ... 057ee3937c

regards