Bob B jack plate

[Pete Craft]

Bob Question for ya....I have a 2011 Z 7 & 150 Pro XS Tempest plus with a 24p. Comes out of hole good 61mph GPS @ 5400rpm. Motor mounted in second hole from top. Top of motor mounting frame is 1.5" above transom. Thinking about a jack plate. Do you think it's worth the money? Will it get me anymore performance? How should it be mounted for max performance? Thanks for your help

 

[Bob Bourget2]

I recommend jackplates on almost all of the "faster" glass boats, typically with V-6 power. Since the Nitro's are built with a safety margin and more or less designed to run with max trim, a weight distribution by the addition of a set-back will yield greater top end speeds with less trim. More efficient prop angle, easier to drive, less prop torque. Each and every boat is different. I would not go more than 6", due to cables and various rigging hardware "extra length requirements". If you have the capability, before purchase, lift and swing the motor back. You should have adequate excess to go back 6". Of course, other "necessities" would include a foot throttle and trim lever, so you can drive the boat SAFELY at top end with TWO hands on the wheel. You can experiment with jack heights, but the most important gauge to watch is water pressure. That motor is designed to run between 11-14 psi at WOT, but I would prefer 15 psi minimum. Keep going up until boat speed drops, water pressure becomes unstable or below minimum. You can also "plug" a couple of the top intake holes for less "air" pick-up at higher transom elevation. My fav manual jack....HydroDynamics "rapid-jack". Easy, light, and strong.

 

[Pete Craft]

Thanks Bob I was looking at the CMS PL-65 HS with 5 1/2" of set back. It's hydraulic with a gauge. I really Thank You for the advice

 

[C Shiner]

So Bob, what is used to plug the water intake holes and typically how many are plugged?



Thanks,

Chaz

 

[Bob Bourget2]

1/16 x 27 NPT allen S/S set screws, drill, tap, red loctite, install. Start with the top two, can go as many as four. Monitor water pressure.

 

[Baja 252]

Just curious, what Lower unit does a 150 Opti have? Does it have a low water intake on the nose? I thought I'd read plugging the top water intake holes was only recommended by Mercury on the 3L torquemaster gearcases.

 

[Bob Bourget2]

Your motor has a conventional 2.5 litre g'case. Plugging the top holes on this style can most certainly be done, but only if the boat / motor set-up NECESSITATES it. High jack heights can and does induce aeration with the stock pick-ups...plugging the "top" holes reduces this.....