[Public-list] Old Atomic 4 Engine Mounts

[Don Campbell]

    The question of engine alignment is always one that those of us who 
do not do it every day might find daunting, particularly when we do know 
that if the shaft is not aligned, cutlass bearings will wear and perhaps 
other stuff that we did not expect will also wear. Both are probably 
correct.
    I have written my method of alignment up for Towney for the upgrade 
of the manual that he is putting together, but that does not help for 
now. This is cheap and easy and with a much greater accuracy than the 
method CB Currier has suggested because it uses the length of the shaft 
to advantage for the measuring. I have copied this from a note I did 
write to one who was about to remove his A4 from an Alberg. This system 
works for any engine and any time.
    I have had confirmation that the system works well by one Canadian 
owner who used a laser alignment system as well as the coat hanger 
needle and his comment was that the chap who owned the laser could not 
believe how accurate the coat hanger system was.
    Perhaps the greatest problem is to know how many shims and rubber 
pieces are between the motor mounts and the beds. Trial and error are 
the guides here.
Don # 528

    The tricky part is to align the motor once it is to go back in and I 
have a set method for that which I find quite easy. I assume you know 
what, if any, washers need to go under the weight bearing brackets that 
hold the motor to the beds. Connect the drive shaft when you have the 
alignment close. Tighten those bolts up well on the coupler. Make a 
pointer out of coat hanger wire or equivalent and sharpen a fine point 
on the end of that wire. Bend it in such a way that the point of the 
wire can be set to just about touching (0.002") at the edge of the aft 
end of the  drive shaft and there are several bends now in the wire so 
that you can tape the wire to the rudder and the point will be secure 
and just about touch the end of the shaft at 12, or 9 or 6 or 3 o'clock 
places if there were a clock face on the after end.  Now using the prop 
if you are alone, or preferably with help from inside the boat, turn the 
shaft. If the point is in a constant alignment with the shaft, it is 
straight and the motor is set. If not adjust accordingly and continue 
until the point is fixed in relation to both a 12 and 6 set up and a 9 
and 3 set up. You need to do both so that the up and down and right and 
left alignment is adjusted. It helps to have a second person so that 
they can turn things and you can adjust from inside. You will find that 
even tightening the motor mount bolts bolts will change the alignment. 
    As an example if you set the wire point to 6 o'clock and turn the 
crank and the shaft rises above the wire, then the front of the motor 
needs to come up so add shims or tighten the back down. If you set the 
wire to 9 o'clock and the point moves into the shaft as it is turned, 
then the front of the motor needs to move to port. Just a bar or a small 
hydraulic jack with a big wooden block as backing on the firewall is all 
you need. Once you think you have things really close, then put the wire 
point on the centre of the shaft and turn it again. It should stay in 
the centre. Recheck things once in the water, and I usually get a pro in 
for that. I have never been more than 0.003 " out though. This takes a 
bit of getting used to the first time but is cheap and easy to do. 
Because it uses the leverage of the shaft to check on the deviation at 
the coupler there is at least  a 15: 1 leverage advantage so it is 
accurate too. Shaft is about 27" and the coupler is about 3" across, so 
1.5 " radius. Use the mechanical advantage to help you as best you can.



 1170340831.0