Thanks Gary. gss036

[technostingray]

Your post to my post was just what I was looking for. I guess it doesn't matter how fast you are going as long as you can't get stopped. I have been told that boat speedometers are notoriously in accurate the current speedometer tops our at 65 but it doesnt work. I want to be able to get two skiers up and am not real experienced in judging boat speeds. What is the minimum speed to get skiers up? Hope this topic is ok for this forum, if not just wanted to make sure you were thanked. :embarrassed:

 

[pwiseman]

Re: Thanks Gary. gss036

One or two skis? Makes a huge difference. I think it is more an issue of having the power to pull them out of the water, which could make this a prop question. Once you get them up, speed won't be a problem as the boat will pull them faster than they will want to go. If you don't trust your speedo a hand held gps is a good tool that will be reasonably accurate. Also, give it a try and see if you can pull them up. You might not have to change a thing.

 

[technostingray]

Re: Thanks Gary. gss036

What is the difference between one and two skis?<br />That is to say, which requires more power. We have not bought skis yet and I had just assumed we would start with two. Others, locally have said forget the skis, get a wake board or..... I have a 60 horse engine, so I wasn't that concerned about the power. Nothing teaches like experience. Still, if experience is the only teacher I have then I may need a new teacher. <br />Thanks for the input.

 

[novicetech]

Re: Thanks Gary. gss036

It is easier to pull two skis out of the water. I do not know if that 60 would get one ski out of the water, maybe if on small boat.

 

[technostingray]

Re: Thanks Gary. gss036

Originally posted by novicetech:<br /> It is easier to pull two skis out of the water. I do not know if that 60 would get one ski out of the water, maybe if on small boat.

The boat is a 14 foot Power Cat Tri Hull. How many Horse would it take to to get one skier out of the water on a 22foot cabin cruiser?

 

[gss036]

Re: Thanks Gary. gss036

Glad my post helped. I don't do sking any more. I used my 23 WA w/200 hp Merc 1st couple years when my kids were small, but that really was not enough power, I even dropped down to a 15 X15 1/4 prop trying to have enough power to jerk someone out of the water. An experienced skier can get up a lot faster than a beginner. My ex-son-in-law was about 250# and I drug him around for 20 minutes and he never did get up. If you really under prop your 60 you might have enough to pull someone up.

 

[technostingray]

Re: Thanks Gary. gss036

Originally posted by gss036:<br /> If you really under prop your 60 you might have enough to pull someone up.

Interesting. Sounds to me like the HP ratings have taken on a new standard. This is from memory and limited experience but it seems to me that years ago a 40 horse on a much larger boat than mine was getting skiers out of the water and pulling them as fast as they could stand. Not barfoot speed, you understand but still thrill speed for the not so daring. Thanks for your help and insight. I will let you know how we do. Oh, when you say underprop does that mean smaller or larger? Can't quite get the theory to compute. Smaller prop quicker revs, but seems that the load would be harder to over come. Thanks again.

 

[Dunaruna]

Re: Thanks Gary. gss036

Ray, your motor has a recomended maximum RPM, if you are not reaching that maximum - you are overproped, you will need to get a smaller pitch prop which will allow the motor to rev higher. <br /><br />If you are exceeding that maximium - you are underproped, you would need to get a larger pitch which would bring down the maximum revs.<br /><br />As a general rule, the smaller you go ,the better the 'hole shot' but you need to keep the max RPM within the manufacturers recomended range. Under revving an outboard causes lugging - very bad. Over revving an outboard causes disintegration - very bad.<br /><br />Does that clear things up for you?<br /><br />Aldo

 

[technostingray]

Re: Thanks Gary. gss036

Yes and no. Horsepower is Horsepower. Load is load. My youngest "hired hand" is the hands on guy in this enterprise. The boat is a gimme. I took in return for labor, as the fellow was without. Once we got it up and running I was all for dumnping it but the 'hired hands' wanted have a boat for at least one summer. All I know is when we took the boat out we were redlining the tack, that is to say it was reading max. Now that you mention it there is no 'red line' on this tac. When I saw the size of this engine and the size of the boat my first thought was that it was way over powered. Initially it felt like we were going go over backward but gradually we got the boat on plane. I had to take my daughter to get a passport for her trip to China so I left. The 'hired hand' trimmed one hole further back and said he was able to get on plane much quicker. I am really not interested in pouring a lot of money into this thing as we are in CA and there is already buzz about phazing out two stroke engines. I only have about a half days wages (a weeks social security in the initial investment but the 'hired hands' have a lot more tied up in the thing. That's OK they are young and have a lot of time to make it up.<br />We are going to take a hard look at where we are. If we can get a summers use out of the thing that will be enough. <br />Theory and application are sometimes far apart, that is where the expression back to the drawing board came from. <br />The prime reason I took this thing in payment was because when Micah, the youngest hired hand was small we used to fill and return the Readers Digest Sweepstakes Entries and I would scribble on the entry, "Where is Micahs' Boat" It was our little bonding thing and a shot at the tactics used by these "entrepreneurs". <br />I don't know how close to WOT we were getting but my seat of the pants experience with engines says we were getting pretty close to max revs. I'll Clam up for now and let you know how things progess. God be with you and yours through this day and thank you for your friendship. It is indeed a small world we live in.

 

[technostingray]

Re: Thanks Gary. gss036

I am not sure where to go with this one. I think the conclusion will be that I am under propped. If that is the case, we will probably just have to let well enough alone. (always a difficult task, especially for me, eh JB) Does anyone from the board have any suggestions or knowledge of what replacing the prop would be. Won't have an opportunity with boat for several days, but sure hope someone picks this up and comments.

 

[Clams Canino]

Re: Thanks Gary. gss036

"Correctly propped" is when the motor makes the required RPM at WOT under "normal" boat load. Nowhere in this thread is your current prop pitch mentioned, so I'll refrain from guessing.<br /><br />Deliberate underpropping is a tecnique often used to get a better hole shot when pulling skiier(s). Just watch the top end RPMS on the tach when underpropped, to make sure you don't go over. <br /><br />I'm very sure that (propped for the job)you can pull a single skiier out of the water on 2 skiis, then he/she/it can drop a ski once up (assuming they have the ability to ski on one ski). <br /><br />I had a 1961 Merc 800 on a very small boat and actually got TWO adult skiiers out of the water using a 15 pitch aluminum prop.<br /><br />My current boat is propped correctly with a 17p SS prop. However, if I'm going to overload the boat and/or pull multiple skiiers, I have a 15p stainless that I'll swap on for the day.<br /><br />Also very important to the hole-shot when pulling is making sure the trim is all the way down or "in". Also, placing your observer as far forward in the boats as possible helps it to get up on plane faster.<br /><br />That's all I know... I don't usually frequent this forum so follow up will be "limited".<br /><br />-W

 

[gwmark78]

Re: Thanks Gary. gss036

Techno,<br />My Mark 78 is rated at 5500 max rpm and I believe your 700 is the same HP and rpm. I pulled my son out on one ski this last week after we got it running on all 6 again. He weighs 170# and is experienced. I learned on our boat 40 years ago also. You do have to underprop somewhat to get out of the water reasonably quick and watch your rpm. I use a 3 blade aluminum instead of my brass 2 blade when skiing. Your 14' powercat is probably heavier than my 15' Alumacraft but should still be able to get an average size skier up on 1. Ebay has quite a few props usually for our vintage motor if yours won't do it.