question about 15' tunnell

[wawa c]

i have a 15' gw invader tunnel hull boat with a 140 johnson. when planed off no matter what the trim setting is it shoots water straight up each side of the motor and into the splash well. i mean a lot of water gets into the boat. is the motor mounted too low on the transom? or what is going on here? i will try to post pictures of the setup as soon as i can. but right now i am on a tablet. i've seen a question of this nature on this site before but can't find the post or if there were any solutions. any help is appreciated thanks

[fs5]

from my experience mate,water usualy sprays up the way your saying from a motor mounted to high.
you still getting water pumpin out the pisser?
are you runnin tabs,or a dolphin fin on the motor?

[wawa c]

thanks for the reply. no dolphin or trim tabs. pees just fine. i don't think it could be mounted too high as the prop shaft is 3" below the sponsons, and the cavitation plate is 4" below the tunnel

[zul8tr]

Show us a side view pic of the transom and motor out of water and any other pics you have.

[wawa c]

here's pics

[zul8tr]

Hard to see in the photo but has the forward edge of the lower anti cav plate been trimmed away? Has the forward part of the upper deflecter plate been trimmed? The upper deflector plate is there to prevent (or reduce ) the upward climb of water spray from the forward edge of the gear case below the anti cav plate and water rise from the rear planning surface from a non tunnel hull. Somewhat unlikely scenario but the tunnel pads do not look that wide at the rear and even though there is a small positive dihedral angle on the pad planning surface that would spray water out, the narrow surface could spray alot of water toward the engine tower and then vertically up? Plus your engine looks kicked out that would force the tunnels deeper at the rear and that contributes to the side spray.
Next time out take have a rider take a video (or pic) of the water action at the rear.

[wawa c]

it doesn't look like anything has been trimmed off the plates. i took this motor off an 19' mark twain tri hull boat that was just used as a family runabout. hard to believe anybody messed with it. the kick out on the motor is just where i sat the engine back down with the power trim for the pictures, it goes further down than that. i ran it at different angles didn't seem to make much difference in the spray. does the height of the setup look ok? i could raise the motor maybe another 2-3 inches with the mounting holes on the swivel bracket. i will try to get pictures of it in action next weekend.

[zul8tr]

The height looks OK for now, run it and get some pics or video of the water as it comes off the hull and as it contacts the motor and rises up.

[Popa Sam]

Appears you about 3" too deep. When you raise the motor enough to stop the transom over wash you will need a different prop.

[Riverrat001]

I agree with popa sam motor needs to go up at least 3 inches. I've never had a problem with water coming over the transom from being to high