Mercruiser engine alignment help

[Darren b]

hey guys I am having a hard time aligning my engine (1991 3 L mercruiser) I took the engine out of another boat and installed it in my new boat (1989 invader) along with a new transom, I have the alignment bar but it really seems like the rear engine mount has to be shimed up, is there a chance that when I drilled my new bolt holes into my transom i was off a bit? because it looks like the holes in the inner transom plate are sloted. the only way i can get the alignment bar sliding in and out somewhat freely is if I drop the front engine mount to its lowest position then when i grease the alignment bar and slide it in and out of the coupler i got heavy spline marks on the top of the bar and light on the bottom of the alignment bar. I have just installed a new gimbal bearing also. thanks guys I need to get this aligned asap because I am renting the alignment tool thanks

 

[Don S]

Re: Mercruiser engine alignment help

If you cut a new hole for the transom shield, yes there is a possibility you got in the wrong place. Did you use the paper template to locate the cutout?


Assuming the cutout is ok, Did you get all the hardware under the rear motor mounts correct?

 

[Darren b]

Re: Mercruiser engine alignment help

I just traced the cutout from the boat and cut my new plywood out and once the transom was glassed I drilled the holes from the back of the boat, but a did have a little trouble lining up the transom plate, but I got all the bolts installed, And yes I have the correct hardware and position on the rear mounts, is it a no no to shim the rear mount thanks

 

[Don S]

Re: Mercruiser engine alignment help

Since you are fairly close, you might try a flat washer under the double wound lock washers under the mounts. Wouldn't go much more than that.

 

[Darren b]

Re: Mercruiser engine alignment help

what,s the max thickness of the washer I could use with out hurting anything? thanks

 

[Don S]

Re: Mercruiser engine alignment help

Just a standard 1/2" SS flat washer. You don't need much.

 

[Darren b]

Re: Mercruiser engine alignment help

I will try it now thanks

 

[Will Fish]

Re: Mercruiser engine alignment help

I had the same issue, and used the same fiber washers and put a slit in them, so they can be put in without taking the bolt completely out. 1 shim on each side and tthe alignment bar moved nice and smooth.

 

[Darren b]

Re: Mercruiser engine alignment help

nice to see I am not the only one who had this problem, So i added one 1/6" galvanized washers to each side of the rear motor mount. With a little front mount adjusting I got the bar slidding in and out with ease. I also rotated the motor every 90 degree and it got a tad stiffer but not much (is that OK?) also I can rock the motor a bit even know I got the front and rear mounts tight, (i would say nomal because they are rubber mounts) How does that affect the alignment when you are ripping down the lake? thanks guys.

 

[Don S]

Re: Mercruiser engine alignment help

Standard ss flat washers are not near that thick, probably closer to half or 1/3rd the thickness. and you would probably still have plenty of adjustment. Now your housing is way off the fiber washers. So, if you loose a coupler real quick, you know why.

 

[Darren b]

Re: Mercruiser engine alignment help

I thought the key was to get the bar slidding in and out free? thanks

 

[Don S]

Re: Mercruiser engine alignment help

I thought the key was to get the bar slidding in and out free? thanks

Sure, that's part of it, but you need to see the big picture, not just one small portion. Go ahead with what you have, it aligns now.

 

[Darren b]

Re: Mercruiser engine alignment help

I am on this forum to be able to see the whole picture, it sounds like you are saying i am setting myself up for a blown coupler? I will try a stainless washer. thanks