87 Cajun 90 In-line question

[crankbearing]

Hey All,

I am putting a 90 In-line merc on an old 87 cajun today BIA style clamps. No jackplate. should the cav plate be level with the pad or above the pad some. This is stock water pickups in the side of the gearcase.

rgds,

Dave

[delawarerick]

Fill the top 3 holes and smooth the intake on the remaining and raise the motor to the top hole even with the pad. And you should have plenty of water pressure and a better top end safely that is what I did on the checkmate inline 6 and I see 54+ it's a heavy 16.5ft open bow. Rick
You might be able to go higher but you must watch your water pressure.

[crankbearing]

So I am ready blow up this Cajun bass boat, I am in the third hole of the motor, about 1/2" below the pad with motor trimmed out a bit and level 90 Degrees to the boat, transom on the boat is 15 degree as far as I can tell and solid. I have given the customer three props from a 19 low rake to a 21 high rake and a 21 chopper . Boat starts up on plane to about 2800 RPm then shoots to the moon and stays there, motor has all kinds of power but just revs the boat will not get on plane. If I trim the motor in to the angle of the transom it is way below the pad, I am thinking wedges straighten the motor on the transom and then set it to the pad or some training wheels

There are no trim tabs or anything on the boat at this point to help it out the tank is at the rear, two batteries. No jackplate motor is mounted on the transom. That 90 is mint, New Rings, 145 a whole on all 6 match cracked capped rods etc ALL kinds of power there.

I am thinkin there is a roller in the boat the motor cannot push it out of. With a 21 that thing should launch on plane. I am told it did the same thing with the 200 Yamaha that was on it previously with wedges but did get on plane with that motor.

rgds,

Dave

[sl!ck]

I would be very suprised if the Chopper worked . In fact, your description sounds like the experience we had with a 16.6 Dynatrac and a 120 Rude and a Chopper. What kind of prop is the 21 High Rake? and does it have vents?