Motor height on my toon

[slo-toon]

I read a post on here a couple days ago and now I can't find it, so correct me if I'm wrong. The bottom of the tunnel in front of the motor should be just above the AV plate when the motor is parallel to the back of the boat. Correct or not? It is a 24' Sun Tracker with a new Mercury 60 HP Bigfoot. Currently it appears to be simply hung on the transom at the lowest possible setting and bolted on. Right now the AV plate measures 3" below the bottom of the tunnel.

 

[Scott Danforth]

'toons are suseptable to loading, which affects engine height. you are correct, most riggers simply bolt the motor on and slap it out the door.

you have to be under-load in the water and then see where the Anti-Cav plate is. you also need to have your typical load on board. Pontoons really need a hydraulic jack-plate in addition to TNT

 

[ahicks]

Jack plate on a 'toon would be pretty cool, but I don't think I've ever seen one.

All the way down is a pretty safe place to install an engine. Works fine for the majority of 'toon owners, most of whom won't give what they are getting for top speed or RPM a second thought.

For those that do give a darn, there are no hard fast rules. The engine pod can be anywhere in a several inch range when compared to the bottom of the 'toons. I think it's a safe bet you'll run into issues with the cavitation plate located above the bottom of the pod. After that though, with the plate located even with or below the bottom of the pod, the higher you can get it to run without cavitating the better! A jack plate would let you experiment with that adjustment pretty easily, but most of us mere mortals will have to get the wrenches out.

If located too high, the engine will cavitate easily, especially in a hard turn.

I would do my testing while lightly loaded, trying to keep that load the same from test to test to minimize variables.

 

[Faztbullet]

Depends on if a tri-toon,log design,and horsepower. A 60HP is min for a 24ft toon so it will run a tad deeper.

 

[slo-toon]

Agree ahicks. I think I'm going to try to aim for center between the two plates on the motor.

 

[ahicks]

Starting out as you're mentioning, and it works out well, will you be left wondering if it might not work better if located a little higher?

If you're going to mess with it, and you can do so with out too much trouble and reasonably safely, I would start with the cavitation plate even with the bottom of the pod and see what that does. If it doesn't work out well, drop it a hole at a time until it does work well. Hopefully you won't be all the way down to the bottom where you are now!

Don't forget to try hard turns!

Best of luck! -Al