Outboard depth in water.

[morbidfollower]

2022 Tohatsu 6hp sailpro with 25" shaft. My motor mount has 3 locking positions. Pictured is the second position, the top position seems to only have an inch or two of water over the extending flat blade portion of the motor shaft. (not sure what its called). I think that's too high, but this middle position makes it tough to run the throttle and in wave action I feel like the motor could get swamped by water at any moment. How do you think it looks, I believe this is the factory mount and location:

 

[pclarksurf]

Looks about right actually-- and yes, top setting is barely enough to cover the intake-- middle is a close to good as it gets, and I can push another notch down, but to your point-- you'll give up the handle at that point. Once I have it running -- i rarely touch it, tiller only and I set the throttle lock and the pivot lock tight enough to move if I have to, but largely set it and forget it.

 

[Joe]

2022 Tohatsu 6hp sailpro with 25" shaft. My motor mount has 3 locking positions. Pictured is the second position, the top position seems to only have an inch or two of water over the extending flat blade portion of the motor shaft. (not sure what its called). I think that's too high, but this middle position makes it tough to run the throttle and in wave action I feel like the motor could get swamped by water at any moment. How do you think it looks, I believe this is the factory mount and location:

Go to Page 21 owner's manual The anti-ventilation plate's position is determined by the bottom of the boat, not how much water is covering it. Unless you have the trim incorrectly set, the boat should stay level under power. Again, all this is in the manual. I have the same motor on my C27, but it's a long shaft, rather than an xtra long, because the mount is on the transom and not adjustable. If you have the motor set too shallow, thinking it's going get swamped, you run the risk of the prop hobby horsing out of the water and over revving. As the previous poster recommended. I do not steer with the motor, unless I absolutely have to.... on my previous 9.9 it was full remote, no tiller. Just lock it straight, tilt the tiller up right so you can reach it. And steer with your boat's rudder.

 

[dlochner]

The middle position looks fine. The outboard cover is designed to drain and prevent water from entering the engine if a wave goes over the top. What can happen is pushing the boat too hard which will cause the stern to squat deeply. At this point you are simply burning up a lot of fuel and not going much faster, throttle back a bit and get the boat to level out.

When I had a OB powered sailboat, I never steered with the motor, always used the tiller. The boat steered better and it was easier.

 

[Tedd]

I can't tell from the photo if your motor is on the centerline of the boat. It looks like it might be slightly to port. My motor is very far to port of centerline and I run the motor very deep, partly so that I can motorsail even on a port tack.

 

[dlochner]

One other thought, If the motor is too deep the prop comes closer to the boat and the rudder when the rudder is hard over. Keeping it at the mid level pushes the blade further aft and away from the prop.

 

[morbidfollower]

Thanks, I was coming back in when the wind conditions kicked up to 25+ and the tide was coming in heavy. The little hole where the water ejects out was basically getting submerged as I would go up and down over the waves. Probably should have tried to sail in. I am still really stern heavy for some reason. I even have 2 group 27 batteries under the v berth but still seem to drag. must be the outboard and the 6 gallon gas can. I have a life sling and magma grill on the back too but those don't really weigh too much. Usually its just me 180lbs and sometimes wife/son (110lbs , 35lbs but they tend to sit next to the companionway). Also have the 5 gallons of water under the v berth. I guess I do have a secondary anchor in the aft compartment where the old battery use to sit with chain and rode. Ill need to go thru and see if I can lighten her up a bit. Maybe that will help with the motor height slightly.

 

[dlochner]

The little hole where the water ejects out was basically getting submerged as I would go up and down over the waves.

The primary purpose of the "pee hole" is to show the water pump is actually working. Most of the cooling water and exhaust is discharged under water.

It is important to remember the Cat 22 was designed back in the day when 2 stroke out boards were the norm. Four stroke ABs are about 20 lbs heavier than a 2 Stroke. Lever that out a foot or so and the effect is magnified.

 

[Gene Neill]

Thanks, I was coming back in when the wind conditions kicked up to 25+ and the tide was coming in heavy. The little hole where the water ejects out was basically getting submerged as I would go up and down over the waves. Probably should have tried to sail in. I am still really stern heavy for some reason. I even have 2 group 27 batteries under the v berth but still seem to drag. must be the outboard and the 6 gallon gas can. I have a life sling and magma grill on the back too but those don't really weigh too much. Usually its just me 180lbs and sometimes wife/son (110lbs , 35lbs but they tend to sit next to the companionway). Also have the 5 gallons of water under the v berth. I guess I do have a secondary anchor in the aft compartment where the old battery use to sit with chain and rode. Ill need to go thru and see if I can lighten her up a bit. Maybe that will help with the motor height slightly.

You will always be at least somewhat stern heavy. It’s an inherent imperfection in the C22, especially the new design.

 

[Joe]

If the boat is hobby horsing through waves while under power, you should slow down and change to a more diagonal course over the waves. This will lessen the up and down action by lengthening the distance between wave peaks.

If your problem is because the boat is "squatting" when under motor power, then you should examine the trim of the motor. Rather than set the trim when the boat is unloaded or sitting on a trailer see if you can adjust the trim while the boat is in the water in its normal, loaded aspect.
Should be fairly easy to experiment with the trim because you have a lifting bracket. The shaft will most likely tilt forward. In the long run, adjusting the ballast will be the big challenge. You could try putting sand bags under the vee berth as far forward as possible.

 

[Jacktar]

Most outboards have an adjustment mechanism built in to the motor clamp to allow adjustment of shaft to transom angle, try adjusting that perpendicular first then look at depth when deployed when running. Cavitation (running prop too shallow) is worst then being too deep.

 

[Benny17441]

2022 Tohatsu 6hp sailpro with 25" shaft. My motor mount has 3 locking positions. Pictured is the second position, the top position seems to only have an inch or two of water over the extending flat blade portion of the motor shaft. (not sure what its called). I think that's too high, but this middle position makes it tough to run the throttle and in wave action I feel like the motor could get swamped by water at any moment. How do you think it looks, I believe this is the factory mount and location:

The flat blade portion is called the "Cavitation Plate" to prevent the prop from gathering and churning air and it needs to be a few inches below the surface. Your engine is fine, but could be a tad lower. Don't be too concerned about dunking the engine power head as the cowling will protect it. Although it is very hard to dunk the power head it is possible under certain conditions in strong foul weather. It happened to us as the stern of the boat fell off a wave and the whole engine went underwater but the stern went back up so quickly that the engine did not skip a beat. There must have been more than enough air inside the cowling. On that run we caught multiple waves but the conditions to dunk the engine were never duplicated. We later removed the cowl and could not find a trace of water.

 

[Davidasailor26]

The flat blade portion is called the "Cavitation Plate" to prevent the prop from gathering and churning air and it needs to be a few inches below the surface.

Isn’t the cavitation plate the one on the bottom just above the prop?

My only experience with outboards is on a dinghy, but for that the manufacturer’s recommendation was that the smaller upper plate should be at the water’s surface.

 

[Jacktar]

Most manuals just suggest that you make sure cav plate is below water level when running at full throttle. Just make it so.

 

[morbidfollower]

 

[morbidfollower]

Reviving this for a moment. Finally have the boat on the trailer. The water rides about 1/2”- 1” above my bottom paint line in the stern. Shown pictures (above) has the motor in the top position of my 3 position mount. Cavitation plate looks to be about an inch below that but not the full hull due to its underbelly shape. Any issues u see here?

 

[dlochner]

Reviving this for a moment. Finally have the boat on the trailer. The water rides about 1/2”- 1” above my bottom paint line in the stern. Shown pictures (above) has the motor in the top position of my 3 position mount. Cavitation plate looks to be about an inch below that but not the full hull due to its underbelly shape. Any issues u see here?

Yes, the prop will capitate because it needs to be in clean water. At the level you have the prop it will be in disturbed water. The motor needs to be completely lowered on the mount.

When sailing the motor should be tilted out of the water and the mount raised. Dragging the prop will add significant resistance and slow the boat.

 

[Gene Neill]

Up position while trailering

Normal motoring position

Bottom position, only when it gets snotty, doesn't look much lower but it makes a big difference

 

[morbidfollower]

Up position while trailering

View attachment 224437


Normal motoring position

View attachment 224438


Bottom position, only when it gets snotty, doesn't look much lower but it makes a big difference

View attachment 224439

Thanks guys. Gene do you tie your motor off somehow when trailering? I basically took all my tail mounted stuff and the motor off the bracket to bring it home

 

[Gene Neill]

Thanks guys. Gene do you tie your motor off somehow when trailering? I basically took all my tail mounted stuff and the motor off the bracket to bring it home

I use a ratchet strap to cinch it up just tight enough that it doesn't bounce around. Provided you have a proper backing plate, there's no need to remove it.