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Author Topic:   Need Advise on New Prop

jmorgan40 posted 06-27-2003 10:39 PM ET (US)
Hello Whaler fans...I have really enjoyed reading your posts the last few days. I hd a 13' when I was young and still remember the great times on it. I bought a 1986 17' Mountauk last week. Really good price ($5,400.00) but it just needs some tender loving care. Also had a 1986 70 hp Johnson and a newer easyloader trailer. The engine had alot of hours on it and a really wanted something a little bigger and newer. Found a guy near by that rebuilt, sold, bought and traded used engines. I originally took it to him to just give the motor a go-over. (All the dealers were a 3 week wait). While there I found he had a 2000 90 hp Johnson 60 degree. The engine was like new, said it had about 25 hours on it and the people let it run out of oil and burned a piston. After about an hour of dealing he agreed on 3,600 for the motor and gave me $1,200.00 for the '86 70 hp. A few extra hundred for new controls, harness and labor. Head is at machine shop and I may have it ready by next weekend. Sorry for the long history...now the question. He is going to put a used prop for it for now. I want to get a new stanless steel for it. What should I get for a 2000 johnson 60 degree 90 hp. I am a big guy and looking for a prop that will get me out of the hole fast and push the boat along at top speed. At most it will be me, spouse, and two teenagers, but all four at same time will be rare...you know teenagers. Any help would be appreciated. Thanks
Sal DiMercurio posted 06-28-2003 12:45 AM ET (US)
First of all, i'd make sure the engine is mounted on the 3rd set of holes from the top, then i'd beg borrow or steal a Stiletto 13.25 x 17 & see where your rpms go.
I think that engine is max 5,500 or 5,800 rpms.
If your not running a big load, the engine should be able to twist it.
If not, let us know & we will go from there.
Sal
montauk madness posted 06-29-2003 01:10 AM ET (US)
Sal,
Will you please give me your advice as well? I have a 91 Montauk with a 91 90hp Mercury (which I'm currently replacing the #1 piston). It is mounted at the right height and has a High Five s/s prop on it. I'm sorry but I couldn't find the diameter or the pitch, however my mechanic said that it was way too much prop for the motor. I would like the best hole shot possible. When the boat was running, I could get 5100 RPM and 42 MPH at WOT and trimmed totally out.
Thank you in advance.
-Jeff
montauk madness posted 06-29-2003 01:09 PM ET (US)
I just determined that my High Five prop has a 22 pitch. Is this way too much?
Sal DiMercurio posted 06-29-2003 05:47 PM ET (US)
M&M, If in fact you are twisting a 22p high 5 at 5,100 rpms, i'd drop back to a 13.25 x 19 S/S Stiletto for $249.00.
Should put your rpms to 5,700 & also maybe more speed on the top end.
I feel this prop should also blow you out of the hole.
Off the top of my head I think your recomended max rpms are 5,500 - 6,000
If it's 5,600 max you should still be fine at 5,700.
Sal
montauk madness posted 06-29-2003 07:17 PM ET (US)
Sal,
Thanks for the help. I'm going to get my block machined tomorrow and pick up a new prop. Is the Stiletto a 3 or 4 bladed prop? I thought I've seen both.
Anyone in the market for a 22 pitch High 5? I live in the Seattle area. It was on a Mercury.
Sal DiMercurio posted 06-29-2003 09:56 PM ET (US)
MM, i'm having a tough time swallowing that your engine, [ 90 merc ] can twist a 22p to 5,100 rpms, sure sounds high for that much pitch.
The Stiletto is a 3 blade, I really, really don't see any need for a 4 or 5 blade on your boat.
A 3 blade will get you up on plane in 3 seconds, a 4 blade 2-1/2 seconds & a 5 blade in 2 seconds, is it really that important to be up 1 second sooner ?
The extra blades knock at least 2 - 3 mph off the top end.
Sal
montauk madness posted 06-29-2003 11:02 PM ET (US)
Sal,
I only could achieve 5100 RPM trimming the engine to the point right before the prop would break loose. The tach was brand new although I was having numorous electrical problems prior to the piston cracking. I have actually only used the boat 4 times due to the problems I've had with it.
The mechanic that is helping me fix it thinks the 22P 5 bladed prop on it could have contributed to the piston problem. He would like to see me put a prop on it that will put less strain on the motor.
Will the 3 bladed Stiletto 19P get on on plane as fast as the 22P five bladed one I currently have. Again, I want to make sure this boat will pull a 200 lb. skier out without problem (if possible). I also would like to have this motor last another summer or two.
Sal DiMercurio posted 06-29-2003 11:33 PM ET (US)
MM, if I were you, i'd get 2 props, one for sking & one when not sking because the 3 blade 19 might not have the umph to pull up a big guy on a deep water start.
I'd still go with a 3 blade Stiletto in 14.25 x 17p just for sking, the extra diameter will give you the lifting properies.
Sal
jmorgan40 posted 07-01-2003 05:41 AM ET (US)
Sal,
Thanks for the advise. I spoke with the mechanic last night and my prop from the old 70 hp was a 13.25 x 17 stainless. I will start looking for the stilleto for later. He also mentioned that he was mounting it a little higher exactly where you said to. Seems like he knows his stuff. Thanks again.
montauk madness posted 07-01-2003 08:39 PM ET (US)
Sal,
I was able to borrow a 20P High 5 and a 13.25 x 19 Michigan 3 blade from a prop shop in town. They didn't have a 17P for me to try. I'm going to try them both this weekend and see where they get my RPMS to.
Sal DiMercurio posted 07-01-2003 09:20 PM ET (US)
Be sure you run the boat load as you normally would, don't run it on an empty tank with no passengers.
Trim it out & check the tach real good.
If it's to high or low, we can get it exactly where we want it.
Sal
montauk madness posted 07-06-2003 04:04 PM ET (US)
Well the good news is that I got the engine back together and it fired right up. I decided to start with the 19P for the engine break-in.
The bad news is that I can only get the boat up to 3900 RPM and the engine is misfiring.
I'm going to install a new trigger and recheck all the carb linkage and see if I can finally get this baby running again.
WhalerGoFar posted 07-08-2003 11:02 PM ET (US)
And I thought I had problems.....all I needed was the right prop in the first place...just to get out of the hole.
Mike
Sal DiMercurio posted 07-09-2003 09:33 AM ET (US)
MM, if that engine was just re-built, don't try & redline it till you get at least a few hours on it.
Sal
montauk madness posted 07-09-2003 11:56 AM ET (US)
Sal,
I will definately try to break it in correctly, if I ever actually get it to run well enough for extended time on the water.
Also, When I was reinstalling the powerhead I decided to raise the motor another notch up. The anti-cav is close to 2" up from the bottom. Is it possible that it is too high now and contributing to my problems?
-Jeff
Sal DiMercurio posted 07-09-2003 04:44 PM ET (US)
I really don't think so.
The only things that it should effect, would be if the engine started to suck air in the water intakles or the prop would ventilate in the turns or trimmed very little, other then that, raising the engine allows the engine to run with less drag or strain.
Sal
montauk madness posted 07-20-2003 11:57 PM ET (US)
Here's an update.
I decided to start with a 3 blade 19P s/s prop for engine break-in and initial testing. I also have the engine (1991 90 HP Mercury) in the 3rd set of holes. The anti-cav plate is close to 2" up.
I'm now getting 5600 RPM vs. 5100 with the 22P High 5 prop). This RPM is with just me in the boat with 13 Gallons of fuel and fully trimmed out.
The boat has a very good hole shot and pulled 200 lbs. out of the water slalom no problem. It hits 42-43 on the GPS.
I still have a few questions if you'll bear with me.
Should I drop down to a 17P to get the RPM's up more? I'm satified with the performance, although I would like to do what's best for the motor. I didn't notice the RPM's when the boat was loaded heavier. The prop I'm using is a Michigan and it's not polished. Should I buy a polished prop? Would a stiletto give even better performance?
Also, the engine ventilates on occasion when I have it trimmed out and turn too sharp or jump on it out of the hole. Should I lower it down a hole? I love the performance. The boat handles very well.
Thanks for all your help with this. I've learned more about boats and engines in the 4 months since I've been going to this site than I thought possible.
Sal DiMercurio posted 07-21-2003 01:06 AM ET (US)
I don't think that engine is rated to 6,000 rpms because thats what you would get with a 17p.
If i'm not mistaken, your pretty close to zeroed in at 5,600 rpms.
I might try droping her down 1 hole to cure the ventilating problem.
Glad she's now running as expected.
Sal
Bigshot posted 07-21-2003 10:31 AM ET (US)
WOT range.....5-5500 on that 90hp.
montauk madness posted 07-21-2003 12:37 PM ET (US)
Is a limited amount of ventilation damaging to the motor? I can control it with the trim. I'm just concerned when others are operating the boat.
Sal DiMercurio posted 07-21-2003 10:22 PM ET (US)
Venvtilating & cavitating can & will pit & burn a prop real bad, to the point of having to replace it if run very long like that.
I know, it sounds strange that water can burn s/s & aluminum, but it's true.
Also. if you allow the prop to vent or cavitate your engine no longer is under a load & will over rev & eventually destroy itself
Sal

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Author	Topic: Need Advise on New Prop
jmorgan40	posted 06-27-2003 10:39 PM ET (US) Hello Whaler fans...I have really enjoyed reading your posts the last few days. I hd a 13' when I was young and still remember the great times on it. I bought a 1986 17' Mountauk last week. Really good price ($5,400.00) but it just needs some tender loving care. Also had a 1986 70 hp Johnson and a newer easyloader trailer. The engine had alot of hours on it and a really wanted something a little bigger and newer. Found a guy near by that rebuilt, sold, bought and traded used engines. I originally took it to him to just give the motor a go-over. (All the dealers were a 3 week wait). While there I found he had a 2000 90 hp Johnson 60 degree. The engine was like new, said it had about 25 hours on it and the people let it run out of oil and burned a piston. After about an hour of dealing he agreed on 3,600 for the motor and gave me $1,200.00 for the '86 70 hp. A few extra hundred for new controls, harness and labor. Head is at machine shop and I may have it ready by next weekend. Sorry for the long history...now the question. He is going to put a used prop for it for now. I want to get a new stanless steel for it. What should I get for a 2000 johnson 60 degree 90 hp. I am a big guy and looking for a prop that will get me out of the hole fast and push the boat along at top speed. At most it will be me, spouse, and two teenagers, but all four at same time will be rare...you know teenagers. Any help would be appreciated. Thanks
Sal DiMercurio	posted 06-28-2003 12:45 AM ET (US) First of all, i'd make sure the engine is mounted on the 3rd set of holes from the top, then i'd beg borrow or steal a Stiletto 13.25 x 17 & see where your rpms go. I think that engine is max 5,500 or 5,800 rpms. If your not running a big load, the engine should be able to twist it. If not, let us know & we will go from there. Sal
montauk madness	posted 06-29-2003 01:10 AM ET (US) Sal, Will you please give me your advice as well? I have a 91 Montauk with a 91 90hp Mercury (which I'm currently replacing the #1 piston). It is mounted at the right height and has a High Five s/s prop on it. I'm sorry but I couldn't find the diameter or the pitch, however my mechanic said that it was way too much prop for the motor. I would like the best hole shot possible. When the boat was running, I could get 5100 RPM and 42 MPH at WOT and trimmed totally out. Thank you in advance. -Jeff
montauk madness	posted 06-29-2003 01:09 PM ET (US) I just determined that my High Five prop has a 22 pitch. Is this way too much?
Sal DiMercurio	posted 06-29-2003 05:47 PM ET (US) M&M, If in fact you are twisting a 22p high 5 at 5,100 rpms, i'd drop back to a 13.25 x 19 S/S Stiletto for $249.00. Should put your rpms to 5,700 & also maybe more speed on the top end. I feel this prop should also blow you out of the hole. Off the top of my head I think your recomended max rpms are 5,500 - 6,000 If it's 5,600 max you should still be fine at 5,700. Sal
montauk madness	posted 06-29-2003 07:17 PM ET (US) Sal, Thanks for the help. I'm going to get my block machined tomorrow and pick up a new prop. Is the Stiletto a 3 or 4 bladed prop? I thought I've seen both. Anyone in the market for a 22 pitch High 5? I live in the Seattle area. It was on a Mercury.
Sal DiMercurio	posted 06-29-2003 09:56 PM ET (US) MM, i'm having a tough time swallowing that your engine, [ 90 merc ] can twist a 22p to 5,100 rpms, sure sounds high for that much pitch. The Stiletto is a 3 blade, I really, really don't see any need for a 4 or 5 blade on your boat. A 3 blade will get you up on plane in 3 seconds, a 4 blade 2-1/2 seconds & a 5 blade in 2 seconds, is it really that important to be up 1 second sooner ? The extra blades knock at least 2 - 3 mph off the top end. Sal
montauk madness	posted 06-29-2003 11:02 PM ET (US) Sal, I only could achieve 5100 RPM trimming the engine to the point right before the prop would break loose. The tach was brand new although I was having numorous electrical problems prior to the piston cracking. I have actually only used the boat 4 times due to the problems I've had with it. The mechanic that is helping me fix it thinks the 22P 5 bladed prop on it could have contributed to the piston problem. He would like to see me put a prop on it that will put less strain on the motor. Will the 3 bladed Stiletto 19P get on on plane as fast as the 22P five bladed one I currently have. Again, I want to make sure this boat will pull a 200 lb. skier out without problem (if possible). I also would like to have this motor last another summer or two.
Sal DiMercurio	posted 06-29-2003 11:33 PM ET (US) MM, if I were you, i'd get 2 props, one for sking & one when not sking because the 3 blade 19 might not have the umph to pull up a big guy on a deep water start. I'd still go with a 3 blade Stiletto in 14.25 x 17p just for sking, the extra diameter will give you the lifting properies. Sal
jmorgan40	posted 07-01-2003 05:41 AM ET (US) Sal, Thanks for the advise. I spoke with the mechanic last night and my prop from the old 70 hp was a 13.25 x 17 stainless. I will start looking for the stilleto for later. He also mentioned that he was mounting it a little higher exactly where you said to. Seems like he knows his stuff. Thanks again.
montauk madness	posted 07-01-2003 08:39 PM ET (US) Sal, I was able to borrow a 20P High 5 and a 13.25 x 19 Michigan 3 blade from a prop shop in town. They didn't have a 17P for me to try. I'm going to try them both this weekend and see where they get my RPMS to.
Sal DiMercurio	posted 07-01-2003 09:20 PM ET (US) Be sure you run the boat load as you normally would, don't run it on an empty tank with no passengers. Trim it out & check the tach real good. If it's to high or low, we can get it exactly where we want it. Sal
montauk madness	posted 07-06-2003 04:04 PM ET (US) Well the good news is that I got the engine back together and it fired right up. I decided to start with the 19P for the engine break-in. The bad news is that I can only get the boat up to 3900 RPM and the engine is misfiring. I'm going to install a new trigger and recheck all the carb linkage and see if I can finally get this baby running again.
WhalerGoFar	posted 07-08-2003 11:02 PM ET (US) And I thought I had problems.....all I needed was the right prop in the first place...just to get out of the hole. Mike
Sal DiMercurio	posted 07-09-2003 09:33 AM ET (US) MM, if that engine was just re-built, don't try & redline it till you get at least a few hours on it. Sal
montauk madness	posted 07-09-2003 11:56 AM ET (US) Sal, I will definately try to break it in correctly, if I ever actually get it to run well enough for extended time on the water. Also, When I was reinstalling the powerhead I decided to raise the motor another notch up. The anti-cav is close to 2" up from the bottom. Is it possible that it is too high now and contributing to my problems? -Jeff
Sal DiMercurio	posted 07-09-2003 04:44 PM ET (US) I really don't think so. The only things that it should effect, would be if the engine started to suck air in the water intakles or the prop would ventilate in the turns or trimmed very little, other then that, raising the engine allows the engine to run with less drag or strain. Sal
montauk madness	posted 07-20-2003 11:57 PM ET (US) Here's an update. I decided to start with a 3 blade 19P s/s prop for engine break-in and initial testing. I also have the engine (1991 90 HP Mercury) in the 3rd set of holes. The anti-cav plate is close to 2" up. I'm now getting 5600 RPM vs. 5100 with the 22P High 5 prop). This RPM is with just me in the boat with 13 Gallons of fuel and fully trimmed out. The boat has a very good hole shot and pulled 200 lbs. out of the water slalom no problem. It hits 42-43 on the GPS. I still have a few questions if you'll bear with me. Should I drop down to a 17P to get the RPM's up more? I'm satified with the performance, although I would like to do what's best for the motor. I didn't notice the RPM's when the boat was loaded heavier. The prop I'm using is a Michigan and it's not polished. Should I buy a polished prop? Would a stiletto give even better performance? Also, the engine ventilates on occasion when I have it trimmed out and turn too sharp or jump on it out of the hole. Should I lower it down a hole? I love the performance. The boat handles very well. Thanks for all your help with this. I've learned more about boats and engines in the 4 months since I've been going to this site than I thought possible.
Sal DiMercurio	posted 07-21-2003 01:06 AM ET (US) I don't think that engine is rated to 6,000 rpms because thats what you would get with a 17p. If i'm not mistaken, your pretty close to zeroed in at 5,600 rpms. I might try droping her down 1 hole to cure the ventilating problem. Glad she's now running as expected. Sal
Bigshot	posted 07-21-2003 10:31 AM ET (US) WOT range.....5-5500 on that 90hp.
montauk madness	posted 07-21-2003 12:37 PM ET (US) Is a limited amount of ventilation damaging to the motor? I can control it with the trim. I'm just concerned when others are operating the boat.
Sal DiMercurio	posted 07-21-2003 10:22 PM ET (US) Venvtilating & cavitating can & will pit & burn a prop real bad, to the point of having to replace it if run very long like that. I know, it sounds strange that water can burn s/s & aluminum, but it's true. Also. if you allow the prop to vent or cavitate your engine no longer is under a load & will over rev & eventually destroy itself Sal