Cylinder head tuning and machining

  • I've got a 2003 restricted 3mb head sitting around so thinking about experimenting on the lathe at home and trying to create an unrestricted, or maybe higher tuned head. Does anyone have some good references for head tuning or any tips? Also if anybody has good pictures of the unrestricted head or even better dimensions of each section that would really help, sadly my unrestricted heads on the bike right now and I won't be able to pull it for a couple months. I know some basics to try avoid detonation, such as a narrower squish section reducing chances etc, but I'm not too clued up about squish heights and compression amounts on the DTR.

  • 3MB head isn't restricted, but can be made better.

    My advice would be to read Graham Bell's Two Stroke Performance Tuning.

    It's not just a case of altering the squish band, but also the head height. Since altering the squish will reduce compression, you need to knock it back up by reducing the head to deck thickness.

  • @Calum I'll take a picture of the head I've got, it's stamped 3MB but it's the one with the ridged, I'll have a look at the book cheers
    I planned on skimming the deck down at the end to create slightly higher compression than standard ideally