Ken
Moderator
I don’t claim to know everything about this but I will share what I do know. Most of my information will relate to the 750's because that’s what I have first hand experience with. Some may not agree with some of the information in here like gasket thicknesses, squish, or decking.
To start off with the port timing is conservative on the Vmax-4's.
The 92's have the most conservative timing, you can go up to a .059" base gasket on the 92's. The 93/94 750's have higher ports than the 92's, so they are usually only raised with a .039" base gasket. I have read some of the dimensional changes to the ports that DynoTech published but I don’t know if they are correct. If anyone has any Yamaha documentation indicating the port changes I’d be interested in reading it.
To start off with the port timing is conservative on the Vmax-4's.
The 92's have the most conservative timing, you can go up to a .059" base gasket on the 92's. The 93/94 750's have higher ports than the 92's, so they are usually only raised with a .039" base gasket. I have read some of the dimensional changes to the ports that DynoTech published but I don’t know if they are correct. If anyone has any Yamaha documentation indicating the port changes I’d be interested in reading it.
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