trim and tilt

pursuit2460

Petty Officer 2nd Class
Joined
Aug 24, 2004
Messages
189
I am not understanding this trim and tilt thing. What do you guys mean by being almost all trimmed out and almost in to tilt. Reason I ask is because I trying to get my motor set up right before summer. When i sent to motor to be rebuilt and got it back I dont know if they put it in the right holes on the bracket. and also what is thiis thing with the water pressure. All i know is I have a 93 225 johnson on a 21cc. I can get up to 47-49 trimming the motor up till i reach 5500rpms and max speed but the temp starts to rise to about 180. I am in la-la land with this didnt think it was this hard. Thanks
 

Rudy Brown

Petty Officer 1st Class
Joined
Apr 3, 2005
Messages
289
Re: trim and tilt

What I mean by it is: Trim is the section the way down or flat against the transom to up until the trim gauge is at its highest level. The trim/tilt on the motor moves slowly thru this range. Tilt starts the fast movement of the motor, from the "up or high trim" to the highest the motor will go. If the motor is moving slow, its in the trim section and moving fast its in the tilt section. <br />I believe you can "over trim" and cause the motor to lose water pressure. I just started playin with my boat, and installed a water pressure gauge for that reason. I hope my input helped and didnt just make things muddy.
 

pursuit2460

Petty Officer 2nd Class
Joined
Aug 24, 2004
Messages
189
Re: trim and tilt

Well that cleared up the trim and tilt question. I just dont have a trim guage. Do you know the max pressure that my motor should have.
 

Rudy Brown

Petty Officer 1st Class
Joined
Apr 3, 2005
Messages
289
Re: trim and tilt

My motor has about 4-5 psi at idle and 25 psi at 5200rpms. I think thats consistant with everyone else's. I just finished up raising my motor 1 hole. The A/V plate now sits 2 1/2" above the keel. I'm going out Sunday and try it out.
 

pursuit2460

Petty Officer 2nd Class
Joined
Aug 24, 2004
Messages
189
Re: trim and tilt

I see you have a 90hp. I have a 225. Are most motors the same psi. Someone also told me that for every 12" of transom braket the motor has to have a 1 1/2 of drop from the keel to the bottom plate of the motor. If I put a straight piece of meal from the bottom of my across to the motor the piece of metal is inline with the middle of the second water pick up hole. This cannt be good right. Thanks
 

Rudy Brown

Petty Officer 1st Class
Joined
Apr 3, 2005
Messages
289
Re: trim and tilt

I would believe most motors would be close to the same pressure. As for the rest of your question, I'm gonna leave that to the more experenced people here.
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,780
Re: trim and tilt

Kenny (Walleyehed) mentioned once that he plugged the upper 2 water pickup holes (assuming 2 on each side) on his engine. He likes to run them (his engines)high and apparently when you do that and you are running at or near WOT there is a trememdous amount of water pressure such that some of the water just turns around and comes out the upper holes which are above the water line when you are running jacked high......the rest goes to the water pump.....which is just along for the ride as the impeller blades are folded back when you are running this hard.....got plenty of pressure as indicated by the pressures in the above comments.<br /><br />Talk to Kenny<br />Mark
 

Texasmark

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Dec 20, 2005
Messages
14,780
Re: trim and tilt

On trim and tilt. My engine apparently has 20 degrees of trim. This is sandwiched between 4 degrees of tuck in tilt and 75 degrees of up or out tilt.<br /><br />The tilt/trim pump has a bypass valve that opens if you are in a tilt position and put too much throttle (pressure)on the engine(tilt/trim piston)....it merely moves to the nearest trim extremity and stays there. Like if you have the skeg tilted (out) 45 degrees from vertical and goose it it will move to like 15 degrees from vertical and stay there.<br /><br />Tilt is really made for slow operation like would be had in a no wake zone. So like if you are trying to get on your trailer in really shallow water and have your engine trimmed (tilted) way out. If you get on the throttle real good, the engine will just move down to the outermost trim position and that's where it will stay till you reduce the throttle and tilt back up, or tuck her in tighter in the trim position.<br /><br />HTH<br /><br />Mark
 

Rudy Brown

Petty Officer 1st Class
Joined
Apr 3, 2005
Messages
289
Re: trim and tilt

Originally posted by Texasmark:<br /> On trim and tilt. My engine apparently has 20 degrees of trim. This is sandwiched between 4 degrees of tuck in tilt and 75 degrees of up or out tilt.<br /><br />The tilt/trim pump has a bypass valve that opens if you are in a tilt position and put too much throttle (pressure)on the engine(tilt/trim piston)....it merely moves to the nearest trim extremity and stays there. Like if you have the skeg tilted (out) 45 degrees from vertical and goose it it will move to like 15 degrees from vertical and stay there.<br /><br />Tilt is really made for slow operation like would be had in a no wake zone. So like if you are trying to get on your trailer in really shallow water and have your engine trimmed (tilted) way out. If you get on the throttle real good, the engine will just move down to the outermost trim position and that's where it will stay till you reduce the throttle and tilt back up, or tuck her in tighter in the trim position.<br /><br />HTH<br /><br />Mark
Thanks Mark, you said (typed) what I was trying to say. :D
 

pursuit2460

Petty Officer 2nd Class
Joined
Aug 24, 2004
Messages
189
Re: trim and tilt

If I lower my engine do stand to lose speed and lower my rpms. Problem is the when I trim it all the way up or to where I get my max rpms and the engine get pretty hot.
 

Rudy Brown

Petty Officer 1st Class
Joined
Apr 3, 2005
Messages
289
Re: trim and tilt

Thats what I'm tryin to figure out with Dhadley's help on my boat. Fine tuning the motor height for the most efficent running boat (and speed).
 

Texasmark

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Dec 20, 2005
Messages
14,780
Re: trim and tilt

10-4 Rudy. Darn. Helped 2 people in 1 week. whadda deal.<br /><br />---------------------------<br />Yes on lowering engine. More engine in the water is more drag and a lower unit is really drag. If you don't believe it run your rig at best WOT and immediately put the throttle in N. See how fast the rig settles down.<br /><br />I had an OMC sieze once doing about 40 mph (thermostat stuck closed and it froze up) It almost threw me across the steering wheel that baby shut down so fast....<br /><br />Before you move anything, why don't you get someone to look over the transom when you are running at WOT on a calm day with no boat wakes and doing it carefully!!!!!!!<br /><br />If your lower unit is spewing water out of the upper inlet holes it should be clearly visable. If so, Kenny can probably tell you how he sealed his.<br /><br />If not you have a different problem causing your engine to overheat; scale, timing, water passage restriction to name a few.<br /><br />Mark
 
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