Twin Drive Alignment?
 

How difficult is it to check the alignment of twin outdrives at home? any special tools needed or is it just a lot of measuring? Are the drives supposed to be dead parallel or do they need to be angled toward or away from each other and does rotation come into play?

It's not that I don't trust the mechanic, I just like to know how it's done and if the alignment needs work.

Measure the centerline of the leading edge of the drive vs. the centerline of the propshafts.

Check the alignment just like Bill272 said. Then play around with the alignment a little. Try a little tow in first 1/16" or so, neutral, and then 1/8" toe in. Check your top speed and handling to see which way you like it.

Matt

Thanks for the replies. I thought that would be one way but was afraid it was too simple!

Another thing to consider is the prop rotation and the amount of "play" in the cross bar linkage. If your props rotate "out" the paddle wheel effect will cause the props to push away from each other. If they rotate "in" the props will tend to pull together. There is also the thinking ( I have to wonder about this ) That on a deep vee hull the water doesn't flow "straight" out the rear of the boat but at an angle due to the deflection of the vee. Like I said...... I have my doubts about this theory.... and that the drives should have a distinct toe in. But my thinking is that you might want the drives to toe in just a little so that they have a tendency to load the cross bar link and keep it from oscillating from a push to pull load that could break some components. I had my boat set up with about 1/4 " toe in measured from the centerline of the propshaft to the little pointy nose on the front (#3ssm's props turning out). That worked best for me and I didn't notice any decrease in top speed. Good luck.

I measured them this weekend and found that there was about 5/8" toe in. Seems a little excessive from what I've read, so I need to contact the manufacturer to get their input. BTW, the props rotate inward.

As you change the alignment the handling of the boat may change. So set it up the way you like it. You will find that different alignments will work in different types of water conditions.

Just change the alignment a little at a time and see what happens.

Some manufacturers may have done a lot of testing with alignment while others may not even know what you are talking about.

Matt