X Dimension
 

So number one what is the procedure for measuring X dimension on a single engine Velocity?

Two, what is your X dimension on your single engine Velocity and what model and power?

Thanks,

Padraig

How far below the pad is your prop shaft now? What prop are you running?

I've never heard of a good process to measure the X after the transom was cut out for the stern drive. If you get a copy of the OEM installation instructions for the transom assembly Mercruiser explains how to measure the X and then install the cut-out template with respect to the desired X dimension. I suppose one could calculate the X dimension by noting the prop shaft relation to the bottom of the hull and subtract it from the distance between the drive's input yoke shaft and prop shaft. Lot's of variables with that approach however!

Maybe I am using the wrong term. I am filling out BBlades test form and it asks for this,

“X” Dimension ______ (center of prop shaft in relation to bottom of boat directly in
front of drive)

So I assume it is measured from the bottom of the boat or maybe the notch? What position is the drive, all the way tucked in or neutral?

Padraig

Measure from the bottom of pad. Out drive in the neutral position. My VR is 3.5" below the pad. Power is a stock internal 496HO.

Easiest accurate way to measure propshaft to pad height is to level the pad of the boat, and then level the propshaft. Place a level straight edge on the floor (most likely will need to shim as most garage floors are not perfectly level) and then measure to the pad, and then to the center of the propshaft. Then subtract the difference.

Easier, not as accurate, is to tape a piece of string to the center of the pad about 3'-4' forward of the end of the boat, and pull tight in your hand past the end of the propshaft. Adjust up and down, until string is just barely touching the length of the boat. Trim drive up or down until neutral trim and measure the difference from the string to the propshaft.

This is how I've done it in the past on the little boats. String method is a quick check if you're at the ramp and wanted to adjust a jackplate for a quick run. ;)

On my 290 SC my prop shaft is approximately 3.75 inches below the bottom of the pad; stock 496HO.

Center of the prop shaft to the center of the pad measurment is 3 -5/8 inches on mine.. It is difficult to be exact, but it's pretty close.

Mine is 2 inches ABOVE.

Thanks everyone! Looks like the string method will work for what I need. Boat is on the lift water so I will wait till I pull it to fill tank or clean.

Tinker, I don't think 2.5 inches above will work for me. LOL

Padraig

It wasn't that long ago when there was no such thing as an X-dimension so we just made sure the cav plate was an inch or two above the bottom of the V.

I guess it's the same as an X-dimension but without the accuracy required for the new age lowers and semi surfacing props!

RR