Prop results

[tbomn]

I said I would post the result of my prop search for my F150 Yamaha/Lund 1800 Explorer. I did a standard black Yammy SS 13 3/4 X 19 pitch, lots of hole shot, and RPM's but no top end. Next was 14 1/4 X 20 Proformance Yammy SS, not as good of a hole shot, not as good RPM's, and not top end. Last, a Pro Series Yammy SS, 14 1/2 X 21 pitch, great hole shot, 5600 RPM's (just right) and top end (51.5 MPH by gps). The 21 pitch did the trick. The Performance Bull. on the Yamaha website said this was the right prop and low and behold...it was. ;)

[czy42strokes]

How is the motor mounted on the transom? Flush or up one hole?

[tbomn]

one hole up, top bolt is in second hole.

[REW]

Possibly the fellow who had the 1800 fisherman with his Yamaha 150 could follow your setup advice. It sounds like you have it knocked.

p.s.
I will also pass this along to my buddy and brother at work who have a similar new rig which they just picked up.

Take care
REW

[PJM]

tbomn


Your results seem very good, now fill up the gas tank and livewells put a couple of people in the boat and some batteries and gear. Now you going to wish you had a 19p on it. Also the warmer the water the slower you boat will go. Getting 5600 rpm ods ok, but being closer to 6000 wide open will make you motor run more efficient. I am not sure why a 19 had such a poor hole shot over the 21 and I no the 21 is vented. Yamaha seems to test there boat in cold water and with like 10 to 15 gallons of gas, so when you fill it up and factor other things in you might be over propped.

[REW]

Joe,
The fact that the last prop was 1 pitch heavier, and just as long, but you gained rpm tells me that the blade area or tips must be different on the last prop, compared to the middle prop.

That is what is so "black magic" about props.

Just because you say that you have a 20 or a 21 pitch prop - does not mean that the engine is going to turn a certain rpm, nor give you a specific performance situation. The design of the blade is so important, the blade area, the blade shape, the rake, etc. etc.

Glad that you have the boat dialed in.
Take care
REW

[tbomn]

>tbomn
>
>
>Your results seem very good, now fill up the gas tank and
>livewells put a couple of people in the boat and some
>batteries and gear. Now you going to wish you had a 19p on it.
>Also the warmer the water the slower you boat will go. Getting
>5600 rpm ods ok, but being closer to 6000 wide open will make
>you motor run more efficient. I am not sure why a 19 had such
>a poor hole shot over the 21 and I no the 21 is vented. Yamaha
>seems to test there boat in cold water and with like 10 to 15
>gallons of gas, so when you fill it up and factor other things
>in you might be over propped.

The fuel tanks were full, the live wells were full, there was two guys in the boat, there are 3 batteries in the boat, and we had all of our gear(rods, net, 5 tackle boxes, lunches)in the boat. The test was to find the correct prop for the rig, and I found it. I have no idea why you want to argue about what I found out. This is my boat, I now have the prop I want, it works extremely well, and I am satisfied with the results. 5600 RPM's is in the top effeciency range for the motor....what more do you want?????

If I want the 19 pitch prop, I will go to the storage compartment in the front of the boat, take it out, and put it on....I kept it for a spare. I don't think that will happen.

[Mother]

tbomn,


The prop sounds close, PJM was on the right track maybe in the
wrong train.

Your squeezing 5600 RPM out of a 'tourney' loaded boat pulling
a strong hole shot and sweet top-end.
Your one hole up on the motor and the 'factory' vent plugs are the
prop.

It ain't gonna get any better - only worse. You will pine for the
catapult holeshot and ballistic top-end this summer. It won't be
there - where did it go, North, along with the cold, dry and dense
air, that made your motor sing. Not to mention the virgin fuel - bone dry, no time for moisture to deflower her.

It's a funny thing how much air can change a motors performance.
Though most don't realize it.

Fast forward to mid June,July & Aug. Hot 90+, humid hazy, no wind.
The boat has been on the trailer/dock since the 4th of July.
Gas absorbing moisture from the humid air for a couple weeks.
You and two buddies are gonna crush some wallies - Big water lake,
a lot of runnin' from spot to spot. You load up, heavy load, you
are planning to be out all day into the evening.
Head out into open water and push her to WOT - It's hot out and so is the bite and minnows are dyin'- hey what the ? Man I can't get
even get close to 50 ??? and I can't pull RPM without over trimming !!
Where's all my speed, my holeshot and my RPM ??
- poof! into THIN HOT HUMID no horsepower making air.

Moral - do not test in absolut perfect condtions-unless you live in absolut perfect condtions. And we don't

Raise her one more hole and try the 19 pitch Pro Series, You need to be at 6000+ RPM with a moderate load, so you can pull
the RPM when your heavy and it's hot. it's easy to limit RPM with trim
and throttle but, if you can't get them when your out of throttle and trimmed to the 100ft roost, your just making noise and burning gas.

Heck, your planing speed will go down to boot.

Mother

[Seldom Seen]

tbomn

I want to chime in on this because I have read Yamaha performance bulletin also. Why is your boat even faster with all that weight then the boat with less weight? You must have a very strong motor or a very strong GPS. That boat did not slow down at all with all the extra weight which is amazing and I have the same boat.

[tbomn]

I have no answer for you. All I can do is put you in the seat next to me and take you out for a ride. You can watch the same GPS I am looking at, and you can see the same tachometer I am looking at. If you would like to take a ride all you have to do is email me and we can go to the river. If you are unable to do that, then I guess you will just have to take my word. It is the truth. That's all I can say on the matter. As the other poster mentioned as the weather changes so might the results, I really don't have any control over that. If you would like to discuss this further, email me and I will give you my phone number and we can talk.