the measurement for x dimension means, let say 17" would that mean from botton of boat up to center of the crankshaft 17" ?

The 17" would be from the bottom of the hull to center of the crankshaft.

ok thank you Griff.

Probably wrong....I thought X dimension is relativity between centerline of "0" trim prop shaft and hull bottom directly in front of drive nose cone. Subject to prop design being surfacing or submerged, the X is usually adjusted up or down.

No, thats prop shaft depth. Griff describes x dimension correctly. Many people when refering to prop shaft height erroniously refer to it as x dim.

Thanks Guys....Griff My Bad....Blue Thunder, you're correct, had to look at the Mercury Book.

hey griff,
i understand what you are saying here however i have a question for you.

lets say with a V bottom twin application. do you measure straight down like with a plumbob from the center of the crankshaft to the point where it intersecs at the V?

or is it still considerd to be measured to the very bottom of the V?

The X dimesion i most often i refer to is the drive / prop height at 0 trim and measure straight upward to the bottom of the hull from the center of the prop shaft. i am not disagreeing with you at all just wanted to clarify the correct way of measuring the true X dimesion.

thanks for your help in advance.

john

Is there a simple way to measure the X dimension with the drive still on the boat?
Thanks,
Bob

It is still measured from the bottom of the V, as far as I know.

If I remember correctly, The actual X is 9 1/4 inches higher than the bottom of outside transom assembly.

You want the propshaft parallel with the bottom of the boat when measuring.

The propshaft depth is really what is most important anyway. It is also much easier to compare and measure. Most single engine V's are going to have an X around 17-18" an dthat will put the propshaft about 4-5" below the hull.

Thanks Griff!! You are a true asset to this forum!!