Engine position

[Shannon C.]

Hello everybody,
I’ve been flying commercial aircraft since I was 23yrs old and I have to go see an FAA physician every 6 month and during the exam I’m required to do a vision test same as you would for a drivers license. Today I was down at the boat yard getting my 300 Marlin ready for salmon season as they are finally opening up the boat ramp in Santa Cruz, anyway, back to my story. Now, I had the mid section replaced due to corrosion on the port engine in November of last year so it’s been on the trailer since then. Now, mabye I’ve never notice this but it appears too me that the starboard engine is a little turned in towards the port. I’m almost 49 and I know that the eyes do strange things but damn that looks crooked to me!! Is that normal?

What do you smarter people think ,lol!!!

 

[DennisG01]

Put a straight edge across the prop hub and compare one side to the other. A 3' piece of straight 2x should do the trick. Or anything that's nice and straight.

 

[Halfhitch]

Measure the length of shaft exposed on either side of the steering cylinder. When you turn the steering wheel to make one steer cylinder have equal shaft exposure, then the other should be equal also. There is arguments about whether the engines should be toed in slightly instead of straight ahead. Personally, I'm a straight ahead believer.

 

[seasick]

Measure the length of shaft exposed on either side of the steering cylinder. When you turn the steering wheel to make one steer cylinder have equal shaft exposure, then the other should be equal also. There is arguments about whether the engines should be toed in slightly instead of straight ahead. Personally, I'm a straight ahead believer.

I have spent a lot of time, trying to find the correct motor angle for my other boat Mercs. I found a lot of confusion and different uses of the phrases Toe In and Toe out. When the prop shafts are angled in towards each other a bit, that is Tow Out and not Toe In as many call it. To make it easier to understand, stand behind the boat facing the motors and look down at your feet. If you spread the toe end of your feet apart a bit, that is Toe Out even though the prop shafts are angled in, towards each other.
That said, some hulls like toe in where the wakes of the motors cross some distance behind the boat when cruising. The typical distance for the cross is 20 to 50 feet in many cases.
Some hulls like Toe In where the wakes diverge away from each other. And some hulls like 0 toe in which is also 0 toe out

The desired setting depends mostly on the manufactures recommendations for a specific hull.
I am currently working on a strange handling issue with my other boat that it has had since I got it a few seasons back. Most of the first two seasons the boat didn't get run a lot since it had a ton of issues. Late last season I did get 12 or so hours on the water and tried to understand the handling issue. I think it may be the Toe Out setting but it also could be a steering issue. One thing at a time though. I have adjusted the tie bar to slightly angle the prop shafts in a bit. They were a bit angled outward before the adjustment. Hopefully I will launch in a week or so.
And don't tell about the method of disconnecting the tie rod and going for a run to see where the motor ends up. I think that is nuts

 

[Shannon C.]

I didn’t notice it when I bought it last year, maybe I was so stoked it got past me. The connection rod doesn’t look as if it was adjusted when it came out of mx last fall. I dunno.
Great advise, thanks guys for your input.

P.S.
If the measurements do confirm it’s toed in a bit, can I disconnect from the motor, loosen the nut and adjust or is there some sort of math wizardry to this because I’m not good with math in public. Lol.. Thanks again.

 

[seasick]

It depends on the specific steering system but in general you remove the bolt on tie rod ball joint. After that is removed, the end fitting that is screwed onto the tie rod can be turned to shorten or lengthen the overall rod length. I strongly suggest yo look up the instructions on the manufacturer;s website (the steering manufacturer)
Mis-adjusting the fitting could cause either binding and damage to the rod or in worst case a loss of steering.

Also, as I mentioned, you want some toe out which is the motors angled in a bit at the prop shafts. The Yamaha rigging manual calls for about a half to an inch of toe out measured as the difference from the front steering bracket to bracket distance less the prop shaft to prop shaft distance. Before adjusting anything, measure the current prop shaft to prop shaft distance and make a note.
I find it a lot easier to just measure the motor mounting bolt hole center to center distance. Let's say that is 26 inches(check that number!). Start with about 1/4 or 3/8 inch of difference at the prop shafts. In my example, adjust the tie rod until that distance is 25 3/4 inches. The prop shafts are now slightly angled towards each other. Both things up and see how the wakes look.

 

[Bloodweiser]

Id say get the boat on some water first before adjusting anything. might be alright the way it is.

 

[seasick]

True, it might be. A measurement of the current setting wouldn't hurt though as a reference.

I did see another check regarding motor alignment that I was not aware of at all. That measurement is the vertical alignment of multiple motors.
To check, measure prop to prop and compare that to the center line to center line distance between the top of the cowlings.The measurements should be the same. Granted, that is not something one could easily change but it is possible that the mounting holes weren't aligned up correctly.Not saying that is the case here, just rambling

Perhaps some folks out there have pictures of their wakes for twin motors. I am curious how they compare to the Yamaha general spec.

 

[Punch53]

I think the curve of the transom makes the engines toe out when raised.

 

[Shannon C.]

Id say get the boat on some water first before adjusting anything. might be alright the way it is.

Thanks bloodweiser, I did have the have the boat in the water last summer and put around 150hrs on the engines low and high rpm and didn’t notice any correction needed, mabye they have been that way since they were mounted. Original motors with the boat.

 

[Shannon C.]

It depends on the specific steering system but in general you remove the bolt on tie rod ball joint. After that is removed, the end fitting that is screwed onto the tie rod can be turned to shorten or lengthen the overall rod length. I strongly suggest yo look up the instructions on the manufacturer;s website (the steering manufacturer)
Mis-adjusting the fitting could cause either binding and damage to the rod or in worst case a loss of steering.

Also, as I mentioned, you want some toe out which is the motors angled in a bit at the prop shafts. The Yamaha rigging manual calls for about a half to an inch of toe out measured as the difference from the front steering bracket to bracket distance less the prop shaft to prop shaft distance. Before adjusting anything, measure the current prop shaft to prop shaft distance and make a note.
I find it a lot easier to just measure the motor mounting bolt hole center to center distance. Let's say that is 26 inches(check that number!). Start with about 1/4 or 3/8 inch of difference at the prop shafts. In my example, adjust the tie rod until that distance is 25 3/4 inches. The prop shafts are now slightly angled towards each other. Both things up and see how the wakes look.

View attachment 12945

It depends on the specific steering system but in general you remove the bolt on tie rod ball joint. After that is removed, the end fitting that is screwed onto the tie rod can be turned to shorten or lengthen the overall rod length. I strongly suggest yo look up the instructions on the manufacturer;s website (the steering manufacturer)
Mis-adjusting the fitting could cause either binding and damage to the rod or in worst case a loss of steering.

Also, as I mentioned, you want some toe out which is the motors angled in a bit at the prop shafts. The Yamaha rigging manual calls for about a half to an inch of toe out measured as the difference from the front steering bracket to bracket distance less the prop shaft to prop shaft distance. Before adjusting anything, measure the current prop shaft to prop shaft distance and make a note.
I find it a lot easier to just measure the motor mounting bolt hole center to center distance. Let's say that is 26 inches(check that number!). Start with about 1/4 or 3/8 inch of difference at the prop shafts. In my example, adjust the tie rod until that distance is 25 3/4 inches. The prop shafts are now slightly angled towards each other. Both things up and see how the wakes look.

View attachment 12945

Thanks seasick, you are a wealth of information sir and I really appreciate it, but based on the diagram you provided it looks as if the port and starboard are angled in towards each other. When looking at the motors from behind and looking down at them standing on the fish box it appears that the port motor is straight and the starboard is toed in a bit. Having a type A personality it DRIVES ME CRAZY!! I haven’t had it in the water yet this year, oh well. Like bloodweiser said get it in the water and see what happens. Thanks for the info to all, I’ll keep you posted.

 

[georgemjr]

With no greater wisdom to add to toe in and toe out, I will add this: It is highly, highly unlikely that the toe has changed since you purchased the boat. A powerhead removal for exhaust work does not even disconnecting the steering. Even if it did, it is almost unfathomable that the steering would be adjusted as there is zero reason for that. You most likely just noticed something that was there already and are now letting your type A drive you nuts. Take measurements because you can, then launch it and enjoy it for another 150 hours as you did last year. It is most likely the setting that was installed at the factory.

 

[seasick]

With no greater wisdom to add to toe in and toe out, I will add this: It is highly, highly unlikely that the toe has changed since you purchased the boat. A powerhead removal for exhaust work does not even disconnecting the steering. Even if it did, it is almost unfathomable that the steering would be adjusted as there is zero reason for that. You most likely just noticed something that was there already and are now letting your type A drive you nuts. Take measurements because you can, then launch it and enjoy it for another 150 hours as you did last year. It is most likely the setting that was installed at the factory.

I agree. The adjustment in all probability has not changed. I mentioned the measurement just to see what the adjustment is. It may have been wrong from the start.

 

[seasick]

Thanks seasick, you are a wealth of information sir and I really appreciate it, but based on the diagram you provided it looks as if the port and starboard are angled in towards each other. When looking at the motors from behind and looking down at them standing on the fish box it appears that the port motor is straight and the starboard is toed in a bit. Having a type A personality it DRIVES ME CRAZY!! I haven’t had it in the water yet this year, oh well. Like bloodweiser said get it in the water and see what happens. Thanks for the info to all, I’ll keep you posted.

Sorry to chuckle but you made me laugh. If one motor is straight and the other appears toed OUT ( meaning the motors are angled toward each other ) Then just turn the steering a bit! The straight motor now angles in a bit and the other angles in a bit less than before

 

[seasick]

I think the curve of the transom makes the engines toe out when raised.

I don't think I buy that argument. If the motors are installed parallel to the keel center line then they should maintain that alignment as they are tilted up. What you may see is one motor turning more than the other when one motor is tilted up more than the other due to the geometry of the tie rod. The effective length of the tie rod will change when the rod is not level as is the case when the motors are not trimmed at the same angle.