7.4 mpi alignment

[lee515]

I'm new to this forum and have been reading all the post on this subject. I replaced a 7.4 gen V mercruiser with a 7.4 MPI. I also replaced the gimbal bearing and grease seal.
I'm having trouble getting my newly installed 7.4 aligned. The engine went back in as expected, I used the existing motor mounts with new bolts washers and nuts. After tightening the bolts I can spin the fiber washers between the motor mounts and the ears on the engine. Is that correct, is the motor resting on the lock washers and transom plate correctly? After reading the posts, I may not have the gimbal bearing aligned yet. But I'm still concerned about the fiber washers.
Thanks for any advice

 

[alldodge]

What is the engine serial number or year?
Is this the original motor, transom assembly and flywheel housing that came from the boat, or were any of the previous parts changed from another motor?

 

[lee515]

s/n 0L042131, the engine and coupler were replaced together as pulled from another boat, everything else was on the boat before, The old engine was a 96 7.4 and the replacement is a 98. I verified with a local mechanic that the motors were interchangable.

 

[alldodge]

Yes motors are interchangeable, but the flywheel housing change and went from spring washers to flat washers. If your motor is high and needs to go down, then remove the spring washer

 

[lee515]

So the fiber washers should contact both the engine and the transom plate.

 

[Bt Doctur]

Not exactly, if you are using the old style rear mounts you need the double spring washer,and the fibre washer can rotate if you are using the newer style, "knurled end" you use no washers or a thin SS one to set the rear height.

 

[alldodge]

BT my understanding is he has the same 1996 transom plate that came on the boat, but has a 1998 flywheel housing. This is about the time that the flywheel and/or transom plates were being changed over. This is also during the time of the serial number breaks

 

[lee515]

I verified this morning the part numbers for the flywheel housing, and motor mounts are the same for both engines. I also checked the transom plate and only one part number was used for all bravo 3, even with the knurled mounts. I had checked the motor mounts the other day and they are smooth on the bottom, not knurled. So the double spring washer is correct and the fiber washer should be able to spin. That leads me to believe the motor is mounted correctly, and the problem may be the gimbal bearing is not aligned correctly. Any second opinions.
Thanks for the help.

 

[alldodge]

When the alignment bar is inserted it needs to be smacked with your hands, up/down/left/right a couple times. This tries to center the bearing with the coupler.

Best way to adjust a new motor, is have the motor mount feet secured to the stringers. Loosen the top nut on front mounts, then lift the front by the thermostat housing lift ring, just barely above the lower nuts. Raise the nuts to where they just touch the lower side of the front mounts.

Now adjust the port and starboard mounts evenly up or down to bring in the alignment

Will go back to, at which direction does the motor appear to need to be moved, up or down?

 

[lee515]

I got the service manual for the engine. Here is the alignment specs

Lift engine into position (in boat), using an overhead hoist.
Align rear engine mounts with inner transom plate mounts while simultaneously aligning
exhaust tubes with exhaust pipe hoses (bellows).

Install both rear engine mounting bolts and hardware. Torque to 35-40 lb-ft
(47-54 Nm).

Set engine down on stringers and relieve hoist tension.
Disconnect sling from engine lifting eyes and move sling to center lifting eye.

Align engine as follows:
a. Attempt to insert solid end of Quicksilver Alignment Tool through gimbal bearing and
into engine coupler splines. If it will not insert easily, proceed to following.
b. If the tool does not fit, remove it and carefully raise or lower the front end of the
engine, as necessary, and attempt to insert the alignment tool.
c. Repeat step “b” until the alignment tool installs easily (SLIDES IN AND OUT
FREELY WITH TWO FINGERS) all the way into and out of engine coupler splines.

IMPORTANT: Turn both front engine mount adjustment nuts an equal amount in
direction required to align engine.

d. Adjust front engine mounts until they rest on boat stringers.
e. Relieve hoist tension entirely and fasten both front mounts to boat stringer using
appropriate hardware (lag bolts or through-bolts, etc.).
f. Recheck alignment with alignment tool. Tool must enter coupler splines freely. If not,
readjust front mounts.
g. When alignment is correct, tighten locknut or nut with lockwasher on each mount
securely
h. Bend tab washer down against flat on adjusting nut.