My TR-185 performance

[Bassinkorea]

I finally got to play with my boat speed last weekend. Here's what I got so far from the 150hp Optimax with jack plate (not sure what the prop is, will check that next time I'm over at the boat storage).....

56 mph GPS @ a fraction over 5000rpm

That was with 2 of us in the boat, rough water, a slight tail wind, fuel tank 3/4 full and a bunch of fishing gear.

[BassBUFF]

Not too shabby . Get the prop info and measure your prop to pad distance. We can tweak it from there.

What was the water and air temp?

[Bassinkorea]

Not too shabby . Get the prop info and measure your prop to pad distance. We can tweak it from there.

What was the water and air temp?

I'll post back here when I get the prop info.
Water temp was 50~52* and air temp was about the same.

[Bassinkorea]

Ok, I finally got over to the boat this afternoon and got some info and photos. Here's what I have on my boat and how it's set up....

The prop (which has a couple of nicks in the blades).....







The jack plate (which I don't know much about)....

[BassBUFF]

Looks good Steve! Can you measure how far below the pad your propshaft sits?

[Bassinkorea]

Looks good Steve! Can you measure how far below the pad your propshaft sits?

I'll measure that next time I get over there (the boat is stored 1 hour away from home). By "pad", I assume you are talking about the lowest part of the hull/keel below the transom?

[wvbassangler]

Hey BK I would go with a 25P and them TR's like it deep I here.  I would start with 6" below the pad and go up from there. make sure to watch your water pressure
1. Leveling the boat using a level on the pad.
2. Measuring the distance from the pad to a level concrete floor.
3. Leveling the engine. (Use the trim button and move the engine, not the boat)
4. Measuring the distance from the center of the prop shaft to the floor. Now just subtract the prop shaft measurement from the pad measurement.

[Bassinkorea]

Thanks for the explanation WV, I'll give it a try next time I'm at the boat.....on Wednesday.

[smallie hunter]

I think a 25 is too much for a 150. I have a 175 HPDI and run a worked 23. I am going to try a 25 next summer but think a 24 would be best.

[Bassinkorea]

Today I measured the pad to prop center distance and the prop center is about 4.5" below pad.

[-Shawn-]

Do you know what the gear ratio is on your Lower unit?
If we have that we can plug it into a Prop slip cacuator and se what we are working with. 

[smallie hunter]

What is good for slip?

[Bassinkorea]

Do you know what the gear ratio is on your Lower unit?
If we have that we can plug it into a Prop slip cacuator and se what we are working with. 

I have no idea Shawn, how would one go about finding out?

[-Shawn-]

What is good for slip?

Less than 10%.

[-Shawn-]

I have no idea Shawn, how would one go about finding out?

Here is a site that gives all the info for merc motors.

http://www.piranha.com/Mercury_Outboards.php

Looks Like it is 1.87:1

What year model is it?  That way we can get the correct amount of min and Max  WOT.

Never mind everything pre 2010 was 5000 and 5600.   

[-Shawn-]

Ok, The slip is 14% and the RPMs are at the bare minimum.
The slip is on the high side, but,The slip is probably due to the dings in the prop.  Minor dings will kill prop performance.

How far can you trim up before the roostertail is above the engine cowling?

How far do you trim up to get your max speed?

[BassBUFF]

4.5" seems to much for a Triton w/jackplate. 3-3.5" is always a good starting point. I'd also bet a 23p would work better.

Shawn has got the right info for ya.

[Bassinkorea]

Ok, The slip is 14% and the RPMs are at the bare minimum.
The slip is on the high side, but,The slip is probably due to the dings in the prop.  Minor dings will kill prop performance.

How far can you trim up before the roostertail is above the engine cowling?

How far do you trim up to get your max speed?

Ok, buying a new prop will be simple and may help. Will I be best to stick with the 23P or try a different size? (I don't have access to various sized props to try).

I haven't tried trimming up with a high rooster tail so far. Last time on the water I was playing around with the trim at WOT and the best performance/revs was at the readings I posted in the first post of this thread.....I just could not get the revs any higher than 5,100rpm.

4.5" seems to much for a Triton w/jackplate. 3-3.5" is always a good starting point. I'd also bet a 23p would work better.

Shawn has got the right info for ya.

I will adjust it by 1/2" or 1" next time I get to the boat. I'll have the boat in the water next on Jan 8th for a (cold) tournament.

Now, to adjust the jackplate height, let me know if this process is right.

1. My jack plate appears to have 2 locking nuts/bolts on each side, and an adjusting nut on the top.




2. So, do I loosen the 4 side locking nuts and simply adjust the top nut whilst measuring the amount of adjustment in the "long" slot holes on the side of the JP??

[-Shawn-]

Yep, Loosen the 4 locking bolts on the side and then ajust with the nut on top.

Most of the time you would only go 1/4" at a time and test.  You want to go up untill to either.......
Gain rpm and loose speed or until you water pressure drops below 15 lbs.

I would think a 1/4 to a 1/2" will help.

[wvbassangler]

I agree with shawn, move it up a little.  Your RPM's should go up a little keep in mind a higher pitch prop will make your R's go up too.
Hey shawn do you know the max on the power pack on that model ?

[SNAGGER51]

wvbassangler,
   Just trying to learn. I thought higher pitch would lower your RPMs. Please correct me if I'm wrong... thanks in advance.

[bass1cpr]

   Snaggers you are correct roughly 200 to 400 rpm drop depending on set up.

[-Shawn-]

I agree with shawn, move it up a little.  Your RPM's should go up a little keep in mind a higher pitch prop will make your R's go up too.
Hey shawn do you know the max on the power pack on that model ?

Merc says 5600.

[wvbassangler]

Yeah sorry about that I did post it wrong

[wvbassangler]

Merc says 5600.

He should be good then, just a few minor adjustments