determining which prop to buy

[MASTER Brian]

Re: determining which prop to buy

Dhadley, does it look like I could still raise the motor? Did you see the pictures and if so, were they clear enough as far as the mounts? I think I mispoke on my first message regarding motor height, as the motor is definately sitting higher on the transom. I'll try to get another picture.

Is there a formula to tell if you can raise the motor more? You speak of venting, but I'm not sure I totally understand it. Are you speaking of venting at the prop, which I understand deals with hole shot, or are you speaking of venting when the boat is trimmed up at WOT?

I get real uneasy, when I get to the top of the trim range, as I don't know how accurate my gauge is (I know some don't even use gauges and can tell by feel) and I don't want to hurt anything. I just don't know how to tell when I'm too high on the trim at WOT. Is it possible to hurt the motor, if I overtrim, or if I'm just easing into it, will it just start to give me a warning??

I also understand that the Raker is a vented prop.

I hope I'm not repeating myself/my questions, but I need and want to understand fully. Am I better off and will I get the same results by adding a jack plate? If so, what is a good one to get for a reasonable price? Or am I better off getting a different prop? Does dropping a pitch raise the rpm's across the whole spectrum or just the higher speeds? The feeling I'm getting is like when your car is stuck in some mud and you hit the gass and the wheels won't turn, so the motor just boggs down.

K.P., thanks for the compliments, but the boat pictured isn't my boat, it's the same boat with a different motor and Troller. It's just what I had a handy picture of at the time.

Dhadley, I am also curious, who you recommend to rework my Raker. I have a few small nicks and scratches I'd like taken out. I don't think they hinder anything, but I want it nice. Maybe I'll include a picture as well. Most where there when I bought the boat, but these mud bottom lakes by me suck for having stuff in them, then to control errosion, they keep adding rocks right next to all the ramps.

I'll look into the Turbo Lighting's as well. I'm glad you mention not to but the Raker's reworked, because I did see one or two on Ebay that had been.

 

[Dhadley]

Re: determining which prop to buy

The motor has a total of 4 holes at the top on each side. it looks like the motor is in the 3rd hole so you have one to go. Basically, if you can use all your trim range that tells us that you have a lot of positive trim to help carry the bow. A Raker or Lightning is a bow lifting prop. A bow lifting prop helps carry the nose without over trimming.

Idealy you'd like to only trim far enough so the propshaft is running parallel to the water's surface. Seldom works exactly that way but that gives you maximum forward thrust. The theory is to have the hull up out of the water and the prop running parallel.

Venting can happen at holeshot. at mid range, wot or in turns. When the prop vents at speed, the rpms go up and the speed comes down. Or the rpms start to go up without any gain in speed. That's what happens when the prop loses bite. It has a lot to do with prop design and a ton to do with condition.

Not all props are created equal nor were they intended to be. A SST will run at a higher X dimension than an aluminum prop, a Raker will like more height and a Lightning will run higher yet.

Personally I like a hydraulic jackplate. You can tweak the set up for different loads, water conditions and use. Not everybody needs a hydraulic plate. The manuals work just fine. Personally I like the products from Bob's Machine but there are lots of really good products out there. I like Bob's 4-in-1 manual because of all the options.

Again if you have to use a lot of trim to carry the bow the offset of a jackplate will help lift the nose too. It'll move the motor back which changes the balance point.

As far as rebuilding a Raker I'd send it to Mazco or Leading Edge Propeller if it were mine.

 

[K.P.]

Re: determining which prop to buy

Brian, don't make this more complicated than it is. Your losing sight of the goal in your original post. You wanted better hole shot with a full boat load of people and your current prop is not getting you there when you have a full load. So reduce your pitch a couple inches. If possible, with the same or similar design prop. It's as simple as that.

You said you are not interested in top speed so why spend $1000+++ on a hydraulic Jack Plate? JP's are meant for raising the motor, at speed, to get more speed. If you get a manual jack plate, you'll have to make the choice to sacrafice hole shot for top speed. If top speed is not your goal, your wasting your time thinking about jack plates. That's not what you have explained you want to accomplish with your boat.

I posted earlier what the result is with raising your motor, each hole raise results in an approximate 100 to 150 RPM increase. I'm sure you have the room to raise your motor one more hole but that little RPM increase is not going to help much with your hole shot problem.

You can bog yourself down with increasing confusion or you can take the advice you've been given to achieve your original goal. Lower pitch equals better hole shot!

Here is the best prop shop in the midwest. http://www.dahpropellers.com/

 

[MASTER Brian]

Re: determining which prop to buy

It seems like I rarely use much of the trim range. The only time, I seem to really use much of it, is when I am trying to run fast across the lake. Most of the time, just normal boating, I find that if I run too much trim the nose bounces too much. The nose of the boat is obviously really light and most of the 1200lbs (boats weight) is in the rear, in the form of the motor, batteries, fuel, etc....

K.P.
I saw your response after I started asking the above question. I must have missed the part about raising the motor. Sometimes it takes me being told something a few times to catch on!!

In any case, you are probably correct that I am somewhat loosing sight, but I don't want to regret anything either. I have read in the past about the lugging motor issue and it doesn't sound healthy. I suppose that's why I'm concerned about it. I've rebuilt this motor once and though I don't want to waiste my money, I'd rather spend $300 +/- on a manual jackplate or $1000 +/- on a hydraulic plate than the $3k it cost me to rebuild the motor, because it wasn't running well. The other part is I am the type of person whom likes to know how things work. I'll probably go buy the 22" raker prop, but maybe some day down the line I'll add a jackplate as well, so might as well understand it. I also figure I need to redo the silicone on the motor mount holes, and if it would be better to lift the motor, then that's the time to do it, if that indeed would help some.

Thanks again for all the info.... I'll post results of what I intend to do and Dhadley, if you don't mind explaining my questions, I would appreciate it.

 

[MASTER Brian]

Re: determining which prop to buy

Well, I went to the my local boat dealer and picked up a SST 14 1/4 x 21" prop. He thought the 21" SST would be better than the 22" Raker and he couldn't seem to locate the 22" Raker someone said they had.

In any case, I figure I'll give it a shot, if I don't like it, they'll take it back and let me try something else.

I'll post my results!

 

[MASTER Brian]

Re: determining which prop to buy

Well, I went to the my local boat dealer and picked up a SST 14 1/4 x 21" prop. He thought the 21" SST would be better than the 22" Raker and he couldn't seem to locate the 22" Raker someone said they had.

In any case, I figure I'll give it a shot, if I don't like it, they'll take it back and let me try something else.

I'll post my results!

Ok, well, I know it's been a couple of weeks, but I finally got the boat on the water and it does have a lot better hole shot. I consider myself fairly hard to pull up on a slalom ski, because I pull hard. Don't know why, I just know I do. In any case, the boat was able to pull me up, but it still seemed like it lacked a bit or could use a lower pitch prop still.

My findings when nailing the throttle, while pulling someone would send the tach to about 4000rpm's pretty quickly. At WOT(or close to) I easily got to 5300rpms and felt I had some trim to work with, which is why I say close to WOT. Again normal operating range is 4500 to 5500 rpms.

Do I dare going down a pitch or changing props once again, or should I just stay with what I have? Like I said, it pulled me up, it was a bit of a struggle, but I haven't ski'ed much in several years and I do pull hard. The other prop wouldn't have gotten me up at all. Do I try a 19 or 20" prop, switch to a 4 blade or consider this the fact that it is a bass boat 1st and a ski boat 2nd?

I sure don't want the boat to hit max rpm's during normal conditions....

Edit....I just called the dealer and they said if I go to a 19" prop to change it out imidiately after pulling ski'ers, which obviously would be a PIA. Again, suggestons are welcome.

 

[Dhadley]

Re: determining which prop to buy

It's not unusual on rigs like yours to have 2 props. One for skiing, one for cruising & running hard. You can cruise (obviously) with the ski prop but it'll most likely be a bit inefficient just like an ideal top end prop will be inefficient for skiing.

 

[MASTER Brian]

Re: determining which prop to buy

It's not unusual on rigs like yours to have 2 props. One for skiing, one for cruising & running hard. You can cruise (obviously) with the ski prop but it'll most likely be a bit inefficient just like an ideal top end prop will be inefficient for skiing.

So would you recommend going with a 19" prop or staying with the 21"? At this point, most of my time on the water is spent playing not fishing. The 21" does seem to be a very good all around prop for this boat, at least judging from the 7 hours I spent at the lake yesterday. I can confidently cruise and pull a ski'er, even if the skiing is lacking a bit. I would just like it to "pop" me up faster....

I do plan on keeping 2 props and I will admit, I am partially considering buying a 3rd prop(19" prop), just for days when I go out and ski all day. Installing the 21" prop for most days and the 24" prop during spring/fall for fishing. I just have to figure out how to do that without pissing the wife off.

Is there a quicker method of securing a prop vs. the cotter pin? If I did have to switch the prop a lot, I would worry about either wasting $'s on cotter pins or risk weakening them with constant changes.

 

[Dhadley]

Re: determining which prop to buy

A cotter pin should last years even if you change props all the time. Remember it's not holding anything. All you need to do is spread it apart a little so that if the nut does come loose it won't move. I usually only bend one side anyway. It'd be rare to find someone who changes (tries) props like I do, Walleyehed is about the only other person who I'm sure changes more than I do.

Owning 3 props shouldn't make the wife mad. Just tell her it could be worse. I have over 100.

 

[MASTER Brian]

Re: determining which prop to buy

Owning 3 props shouldn't make the wife mad. Just tell her it could be worse. I have over 100.

I don't think much I do anymore would suprise her.

Thanks for your help/input!!

 

[MASTER Brian]

Re: determining which prop to buy

Well, I had to order something from Ranger Boats, so I figured, while they were on the phone, I'd ask their opinion. They gave me one of their guys, who I guess is a prop expert and he told me that I should look into the 13 1/2 x 21 Renegade Bass 4 blade prop. He said that would do what I needed on this boat with my engine. He said, I'd definately need to watch my RPM's, but this would give me great hole shot.

They don't sell this prop, so I looked online and this is what I come up with a 13 1/4", (he thought it was a 13 1/2, but all I came up with is a 13 1/4) x 21" 4 bladed renegade bass prop. Problem is it says it's for V-4 60 thru 115HP, 3 cyl & V-4, with a part number 176196.

Are they just saying it is for a V-4, mine is a V-6, because that is the prop that would work best on that motor? ....I'm guessing that is the case and it will work on mine, just not the ideal prop for my v-6, but a good prop for skiing.