Merc 35hp Stainless prop and Anoed questions

[Chrisravosa36]

Ok y'all, I'm running a 73' Carefree 13.5ft fiberglass boat. Has an 86, Merc 25. It's running on a short shaft transom. I'm currently running a 12p prop, unsure about diameter. I have the trim on the highest hole, gps gets 25mph on this hole at wot, all the other holes get 23 and about 24. I notice one way turning is easy and one is harder. I was told this could be the trim Anoed. It leans twos the left side. I'm also looking into a new stainless prop, there are a few diffrent diameters and I was wondering what I should go with, I'l get my wot rpm and current diameter tomm. How much speed do you usually gain with a stainless? Also how do I adjust that Anoed? Thanks

 

[Starcraft5834]

install a flat Anoed. otherwise you will have to trim out the Anode fin

 

[Chrisravosa36]

install a flat Anoed. otherwise you will have to trim out the Anode fin

But don't I need a offset because my boat leans

 

[ondarvr]

The fin can offset some of the prop torque, it will have less effect on the boat leaning to one side at speed though. adjust as needed for your type of use. What is the objective of the SS prop? It's typically not worth the investment on smaller outboards.

 

[Starcraft5834]

I put flat anode on my 20ft cuddy, 4 blade..control is no issue

 

[Chrisravosa36]

The fin can offset some of the prop torque, it will have less effect on the boat leaning to one side at speed though. adjust as needed for your type of use. What is the objective of the SS prop? It's typically not worth the investment on smaller outboards.

Some more speed, and I need an upgrade anyways, this prop I have has rough edges. Pj bought a wire tach today to see what rpm I run, I'm going to go out after work and see. I think with a 13.5ft Fiberglass boat and a 35hp I can atleast get to 29mph. I weight about 160lbs, I have one battery in the back, weighing 60lbs, a full 6 gal tank, three tackle trays, a fire estinguisher and a cover, also other electronics, all in all the boat weighs about 700lbs with one person. I also noticed even with my dad and me, I got just one mph less, and he isn't small. 300lbs or so. so I'm guessing it might be the trim I have to play with to get some more speed? I'm not to sure

 

[ondarvr]

I didn't look up a SS prop for that motor, but they're frequently very expensive, and on a small motor you may see little too no improvement over aluminum.

 

[David Young]

Your talking about the little fin above the propeller? If so, I marked mine then adjusted it straight just to see what it would do. I had to keep the steering wheel 1/4th of a turn just to go straight down the lake. I readjusted it to where it was, all is back to normal now

 

[Sea Rider]

Some issues:

-OB must sit right in middle transom, trim tab set at factory is usually set at middle.
-Adjust steering load nut for OB to follow a straight water course when tiller is released, don't overtight.
-With 2 up, one at stern, other up front, bow area.
-Go for a wot spin and trim OB at a trim hole that achieves combo to ride parallel to water level.
-Usually second, third hole out transom
-Pull head back transom and check if having water splashes out transom or over transom.
-Middle wake should be near flat if OB sits at the sweet tarnsom height.
-Tach OB running at wot with 2 up as suggested.
-Report wot wot rpm achieved.
-Will need to know min-max wot rpm factory stated.
-Depending on the reading can go from there maximizing a prop to suit your particular boating style.
-Alum props all the way. On portable OB's an SS prop is throwing money into the blue.

Note : It's just a 25 HP, don't expect to break a world speed record..

Happy Boating

 

[Chrisravosa36]

Some issues:

-OB must sit right in middle transom, trim tab set at factory is usually set at middle.
-Adjust steering load nut for OB to follow a straight water course when tiller is released, don't overtight.
-With 2 up, one at stern, other up front, bow area.
-Go for a wot spin and trim OB at a trim hole that achieves combo to ride parallel to water level.
-Usually second, third hole out transom
-Pull head back transom and check if having water splashes out transom or over transom.
-Middle wake should be near flat if OB sits at the sweet tarnsom height.
-Tach OB running at wot with 2 up as suggested.
-Report wot wot rpm achieved.
-Will need to know min-max wot rpm factory stated.
-Depending on the reading can go from there maximizing a prop to suit your particular boating style.
-Alum props all the way. On portable OB's an SS prop is throwing money into the blue.

Note : It's just a 25 HP, don't expect to break a world speed record..

Happy Boating

Understood, it's acutally a 35hp. I've tried all of the holes, the last hole, trimmed out made the best speed, and moved the spray to the back of the boat, the first two holes kept the spray 2/3 to the front of the boat, the third and fourth were better but the last hole gave me the best results at 25mph. Ok, I guess il go with an aluminum just heard all this craze about stainless from locals. I u dee stand I'm not going to be the fastest one, I'm just trying to get the best results from the motor. The adage of the lower unit is pretty banged up, would it help to smooth this out? Is has a few sharp edges and I belive that would definitely cause some air bubbles. So back to another main question I had, how do I determine the diameter needed. The guy had this motor on a aluminum boat, so I'm thinking the propping out will be a little different. Il get back to you tonight with a RPM statement.

 

[Sea Rider]

Sorry, didn't get right if it was a 25 or 35 HP OB..

For clarification about ideal OB/transom height post a nice pic of actual 35 HP lower leg shot sideways in which both upper and lower horizontal plates are exposed, want to check something, then will work from there optimizing combo performance.

Post pics of what's damaged and combo as well..

Happy Boating

 

[Chrisravosa36]

Sorry, didn't get right if it was a 25 or 35 HP OB..

For clarification about ideal OB/transom height post a nice pic of actual 35 HP lower leg shot sideways in which both upper and lower horizontal plates are exposed,
want to check something, then will work from there optimizing combo performance.

Post pics of what's damaged and combo as well..

Happy Boating

Can't get any good pictures right now, boat is at the lake, il take some tonight wheni head out. Basically there is one that is a semi circle on the skeg about the size of a dime, on the leading edge of the lower unit there a a few small ding, another one about the same size as the one on the skeg. It also has a bumby edge, which I'm sure isn't helping my speed. The prop also has a pretty bad edges, nothing to serious, it's just a few I dentations and bumby, again not helping my spped. As for the plates, the cavatation plate is about one inch under the bottom of the boat, and there are two small plates ontop of that, and so about an inch about, a lot less wide and goes to the end of lower unit, and the top on is about an inch about that that is a lot shorter and same withd as the previous one, right near the lower motor mounts.

 

[Sea Rider]

There is one issue that needs to be addressed spot on, that's OB/transom height.

-Float OB by itself
-Trim to a hole that will sit OB at 90?
-Place one mate up front to balance well combo.
-Go for a wot spin.
-Pull head out transom, sit on floor close to it if you find scary doing so.
-Check at wich lower leg height is middle water flow passing through lower leg.
-As trimmed, check if there's water splashes out or over transom ?
-That cond "needs to be determined" before doing any other thing..
-Ideal OB height is for water flow to pass skimming right under upper water deflector plate.
-Old OB's have a very short distance between upper and lower horizontal plates.

If can post a pic of the combo and OB to have a look will be perfect.
If lower skegs has hits, dings, watever not an issue as long skeg is not bent, same for prop.

After sitting OB at the sweet transom height can go for a prop maximization, provided that OB is 100% healthy..

Happy Boating