Manual jack plate adjustment?

[Desertdog619]

So I have the 6” manual jack plate with my new Mercury 150 ProXS. My buddy noticed that my exhaust was right at the waterline surface when my engine is trimmed in the full down position. He said the exhaust should not be that low or close to the water where it bubbles. Is this correct? If not, how high above the water line should my exhaust port be when the motor is completely down?
thanks for any input on this.

[Hez]

[sclark]

Exhaust - you mean the exhaust coming out of the center of the prop ?

[Desertdog619]

Exhaust - you mean the exhaust coming out of the center of the prop ?

No,not out of the prop. Maybe it’s not the exhaust but it certainly sound like it. It’s about half way up the back of the motor, right below the release handle for the cowling. There is a hole about 1” día that sits at the water level and creates loud bubbling

[SMChamp]

If the hole at the back of the engine is not at least this high, contact the engine manufacture. They probably cut your hole out in the wrong location.

Easy fix.

http://gariebeach.com/product_images...GRB__90212.jpg

[Mr. Derek]

The motor height isn't set based on the exhaust idle releif port. In the manual it says to trim up the motor so the port is above the water when idling the motor.

[Desertdog619]

If the hole at the back of the engine is not at least this high, contact the engine manufacture. They probably cut your hole out in the wrong location.

Easy fix.

http://gariebeach.com/product_images...GRB__90212.jpg

it appears to be in a similar location as your pictures. What is the hole for? Mine has what looks like a rubber grommet around it as well. I tried to post a picture but it won’t accept it due to the size. Trying to figure out how to resize to get it to load. Lol

[Hez]

I tried to post a picture but it won’t accept it due to the size. Trying to figure out how to resize to get it to load. Lol

We got a thread for that:

http://www.bbcboards.net/showthread.php?t=951512

[J Risco]

Set Prop to Pad according to performance (i.e. raise until you loose water psi, speed, or lift... then go back down 1/8"-1/4")

Exhaust relief hole should not factor into engine height, if it is below the water line at idle (when at the best height for optimal performance) simply trim up until it is out of water. Lower engine down once idling in gear to the lowest trim before holeshot.

[Desertdog619]

Set Prop to Pad according to performance (i.e. raise until you loose water psi, speed, or lift... then go back down 1/8"-1/4")

Exhaust relief hole should not factor into engine height, if it is below the water line at idle (when at the best height for optimal performance) simply trim up until it is out of water. Lower engine down once idling in gear to the lowest trim before holeshot.

Thanks. So it’s called an exhaust relief hole? It’s not below the water line when engine is trimmed in full down position and idling in gear. Although, its close enough to the water line to cause bubbling noise. I just wasn’t sure if that was normal. Never heard of an exhaust relief hole.

[J Risco]

Thanks. So it’s called an exhaust relief hole? It’s not below the water line when engine is trimmed in full down position and idling in gear. Although, its close enough to the water line to cause bubbling noise. I just wasn’t sure if that was normal. Never heard of an exhaust relief hole.

Im sure it has a fancy term/name, but that is just what I always called it. Yours sounds like its just fine.

[crank68]

J Risco is dead on !!