RAISING MY 60HP??

[BIGEYEJOHN]

i have a 1600 adventurer sylvan with a 60hp merc tiller with trim/tilt on it. the prop is a 10.25x14 alum. and i run about 33mph at 5000rpms. how can i get a little more speed? the motor is set as as low as it will go, will raising it one hole increase speed? what size prop would you recommend? any help is much appreciated. thx

[Wables]

I raised my 75 HP this spring one hole and gained around 1 MPH, from 35 to 36 MPH GPS. I raised it one more hole and started blowing out. It is on a 1700 Lund Angler, 19 pitch prop and started in the top hole. I can't help you with the prop in your case, though.

[VMS]

You bet you can make some gains by raising the motor up!! Couple of things are going to happen if you stick with the prop you have. First, you will gain RPMs (about 100 or so a hole) so you need to be careful not to go over the maximum RPMs for the motor. Also, you may need to try a different prop to get better bite on the water. If your prop is a stock prop, it probably will not have the bite you would be looking for, hence your motor would quite possibly blow out on slight turns when trimmed up.

If you like where your RPMs are now, you can probably order a cupped prop of the same pitch and diameter (possibly different brand). The cupping will bring your RPMs down anywhere from 100 to 200 RPMs which would keep you in the range you started with. The speed will be anywhere from 2 - 4 mph more depending on the prop you go with. Biggest thing that can change the way the boat handles is the prop. Definitely, find a prop dealer that will let you try different prop brands, pitches, blade style, etc, and see how they perform on the boat. If all props blow out, then you would need to lower your motor one hole and you should be pretty well set up.

This is just a start to what you can do and what needs to be done..but raising the motor is a big step in the right direction to get peak efficiency out of your rig.

Steve

[BIGEYEJOHN]

do you know of any good prop shops in the twin cities area? i am going to raise my motor one hole at a time and try a few different props to see what happens. thanks for your help.

[Crappie Kid]

2-4 mph? That is not worth my time or investment. These are fishing boats not race cars. Sure its fun to tinker but the benefit is minimal.

[Mother]

BigEye

What is the 'redline' / max RPM for ypur motor ? Very critical
If it's 5500 RPM you need less prop or need to raise the motor
one or two holes to get to max RPM

Is the 5000 RPM and 33mph in an unloaded boat ? or did you have
a fishin' buddie, gear and a half full live well ?

Lets say your boat was 'empty' and the engine was pulling 5000 RPM
at 33mph with a redline of 5000 RPM. Not much to gain here, you
really have only one choice of going to a SS prop -
Cabelas and Merc offer very nice mid-level HP SS props.

A SS prop being much stiffer and higher level of blade precision
will slightly lower your RPM. You can raise the motor one hole
and bolt on a same PITCH and DIAMETER. SS and still be at 5000 RPM
And gain only maybe 1-2 mph but, handling and hole shot will be much
improved. OR bolt on a 1-2 degree less PITCH and a 1/2-1 inch larger
DIAMETER SS prop.

Example- if your existing prop is a 13 pitch X 11in. Dia. prop
you can go down in pitch and up in dia. to a 11 pitch
X 12in. dia.

With this route you still maitain your RPM by the increased blade
surface. This set-up will give you great hole shot and lower your
planing speed by the great lift provided by the larger blade. Speed
will be minimally increased. But you can carry three fishin' buddies
and gear with onlya small loss in speed.

Now the fun part- If your max RPM is 5500 RPM we can play with a lot
more stuff. RPM = speed. You want to be at max or over max RPM when
'empty' since most of your fishing is done with a buddie and gear.
You need 500 RPM ,start with a SS prop that is 2 degrees less in
pitch and 1/2 in. larger in diameter and raise the motor two holes.
Okay we gained 100-200 rpm in each 'degree' less in pitch. 300 RPM
gain, lets say. Now with the larger dia. we lost 100 RPM but, we
get it back and more by raising the engine two holes 100-150 RPM per
hole - up two , were at 250 RPM gain.
Lets add it up: + 300 w/lower pitch prop
- 100 w/larger Dia. prop
+ 250 by raising the engine
A net gain of 450 rpm and we are at 5450 RPM, you can get more by playing with the trim - trim out to tickle the redline or trim in
for bite on hard turns and waves and still be in the 'meat' of your
power band.
All that and a nice little gain of 2-4 mph easily
and much improved handling and lower planing speeds. And free
increase in gas mileage through efficiency by lifting more hull out
of the water at lower throttle settings-minimizing drag.

Do you want to spend $200 - $250 on an SS prop and test 3-4 sizes
and change engine heights. A good set-up takes some time and is
worth it.

Mother


ps - and now you have a spare alum. to run for free, sort of !!!

[BIGEYEJOHN]

hey kid, yes i know its a fishing boat, duh.. mother- thanks for all the helpful advise. i ordered my new prop and am going to raise her up one hole, see what happens. I dont mind doing a little experimenting to gain a little in speed. I fish the MWT(minnesota walleye trail) and am always looking for a little more speed to the next honey hole. thanks for you help.

[Crappie Kid]

Sorry you took it the wrong way, I meant for the average fishermen. For a tournament setup the extra speed would be key at times. I get the extra couple miles per hour now that my son is away at college. More room in the boat (less fish too!).

[BIGEYEJOHN]

well if we cant give each other a little #### once in a while what fun would it be?? lol good fishing to ya.

[REW]

Put a 90 hp motor on the boat.
Seriously, any expenditure of money, with respect to changing a motors hp, is largely wasted. To get more speed, you need a substantial change in power.

As the rule of thumb says, a 10% change in hp, will give you a 2% change in speed, for a v bottomed boat on plane.

So, lets say that you bump your hp by 20% - i.e. go from a 60 hp to a 72 (or 75 hp, since it is available).
You will then likely gain 4% in speed.
i.e. you will go from 33 mph, to 35 mph.
Do you really want to spend the money?

Water really is a "drag" so to speak. Once a hull gets on plane, it takes a tremendous increase in hp, to make a substantial change in boat speed.

Take care
REW

[BIGEYEJOHN]

CANT GO WITH A 90. BOAT IS ONLY RATED FOR A 75HP. I DONT WANT TO SPEND THE MONEY ON THAT RIGHT NOW SINCE IM BUYING A NEW LUND IN THE FALL OF 2004. THANKS FOR THE ADVICE THOUGH. GOOD FISHIN'

[BIGEYEJOHN]

i got my new hustler 15 pitch prop, put her on, raised the motor one hole and headed for the lake. before the change i can plane quickly and get 33mph. now i get on plane in a heartbeat and 37mph. very nice change indeed. thanks again for all your help.

[KP]

Hustler Prop? Did they tell you what you needed to achieve the results you wanted, or did you tell them what you wanted?

[BIGEYEJOHN]

i talked with hustler and told them what i had and what i wanted. they set me up with the right prop. im very happy so far.

[KP]

Do you have a number or website for them?

[theoldwizard]

Are you getting any blowout, especially when cornering ? The speed gain does not surprise me too much. You should also get a bit better mileage.

[BIGEYEJOHN]

i went through iboats.com and went to props. there is virtually no blowout and cornering is much improved, so far so good. i had it out on lake mille lacs last weekend and even with the rougher water it performed very well. im going to go to the best walleye lake in minn next weekend(mound lake near alexandria) and see how it handles the smoother water. good fishin'