Boat Prop Selection Help

[ILIKEROSTERTAILS]

Hi again,<br />I got my starter fixed and have had like 5 great boating trips. I was looking at my prop and it is not in verry good shape. It has some like bent places around the edges not to bad. It was painted white and is real ugly. I think my prop I have now is 16in pitch and 13in diamiter? Right now my boat has good acceleration and a good top speed. It is at 4050 WOT. Is that low? If I get a new prop should I get the same size? It is on a 140 hp 3.0L OMC. The boat is verry similer to the this one: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=2486745929&category=63686 <br /><br />Thanks,<br />Ben Hunter

 

[cuzner]

Re: Boat Prop Selection Help

4050 rpm at wot is too low. You can take the prop in to have it fixed this wmight make the missing rpm if its in rough shape.Check the numbers again though, I,ve never heard of a 16p prop,I'm sure someone will jump on me if they are available though.Rpm at wot should be around 4600 for a 3l engine. <br /><br /><br /> Jim

 

[Elk Chaser]

Re: Boat Prop Selection Help

I had a 165 HP 4 cyl and I ran it with a 19 pitch for skiing and a 21 pitch for top end. The pitch you have is great for hole shots, (getting out of the water) but not for your top end. <br /><br />Cuzner is about right, your WOT should be 4200 to 4600 on the 3.0L and 4400 to 4800 on the 3.0L LX. <br /><br /><br />Assuming you have the pitch correct on your present prop...............<br />Figure about 100 to 200 RPM increase with each inch of pitch increase so you can easily go to the 19 pitch for top end. Have the 16 repaired at a shop (fairly cheap) and keep it on the boat as a spare.

 

[cobra 3.0]

Re: Boat Prop Selection Help

How big is your boat? A 16" pitch should give you somewhere around 4600 rpm. It sounds more like a 19" pitch to me to be that low. Recommended rpm range is indeed 4200 to 4600 for a 3.0 OMC 140 hp. which is what I have. My 14 dia. x 17" pitch gives me 4400-4500 rpm depending on how many people are on board.

 

[ILIKEROSTERTAILS]

Re: Boat Prop Selection Help

Hi,<br />How do I measure the pitch? I have unbelivable acceleration. Also will those props with the bigger exaust holes realy add XP?<br />Thanks,<br />Ben

 

[ILIKEROSTERTAILS]

Re: Boat Prop Selection Help

Oh it is 16 feet long.<br />It is a Bayon Custom from Redding California.

 

[ILIKEROSTERTAILS]

Re: Boat Prop Selection Help

Could my prop be ok and maybe my Engine is not able to go to 4600? Like the carb or timing need adjusted? It seems to run good but could that be it?<br />Thanks,<br />Ben

 

[ILIKEROSTERTAILS]

Re: Boat Prop Selection Help

I have one other qeustion also, maybe I should make a new topic? <br /><br />On the back of my OMC engine there is a plate that the shift cable hooks to. There is a little button on the back that gets pushed in when you go into gear. That is a spark intruper switch right? Also near that is a little adjustible slide and a button on the lever that the shift cable pushes and pulls. What is the second button for? Where to I adjust the little slide? If you do not understand what I am talking about I will explain better.<br /><br />Thanks,<br />Ben Hunter

 

[ILIKEROSTERTAILS]

Re: Boat Prop Selection Help

I figured out how to fix buttons. The second one cancels out the first one. It is fixed. Now back to the prop!<br />Thanks,<br />Ben

 

[ILIKEROSTERTAILS]

Re: Boat Prop Selection Help

I figured out that I think it is 15in Pitch and 13in Diamiter. What size should I buy???<br />Thanks,<br />Ben

 

[cuzner]

Re: Boat Prop Selection Help

Try replacing it the same size and keep an eye on your tach.If you don't get better rpm you should be able to exchange it for a lower pitch. You will loose a little top end if you prop down down though.<br /><br /><br /> Jim

 

[cobra 3.0]

Re: Boat Prop Selection Help

Also, your tach may be off. My boat is a 16 ft bowrider and a 15 or 16 " would easily go 4600 rpm or higher. Your boat sounds more streamlined than mine..what's top speed?

 

[ILIKEROSTERTAILS]

Re: Boat Prop Selection Help

I do not know the top speed my speedo is broke. I have acceleration out the *** now. My Tach must be off then I guess. Where should I get a prop from? Also could it be a motor problem that I am not getting full rpms?<br />Thanks,<br />Ben

 

[walleyehed]

Re: Boat Prop Selection Help

When was the last time you had a tune-up...plugs, cap, rotor, sensor...that sort a stuff..????

 

[walleyehed]

Re: Boat Prop Selection Help

http://www.boat-props.com/propellers/ <br />Here's your source for props...

 

[ILIKEROSTERTAILS]

Re: Boat Prop Selection Help

Well I rebuilt the carburetor last year and also got new plugs gaped right last year.

 

[ILIKEROSTERTAILS]

Re: Boat Prop Selection Help

Ok but what brand prop should I go with?

 

[Bayrider]

Re: Boat Prop Selection Help

Originally posted by Elk Chaser:<br /> <br /><br />_______________________________________________<br />Assuming you have the pitch correct on your present prop...............<br />Figure about 100 to 200 RPM increase with each inch of pitch increase so you can easily go to the 19 pitch for top end. Have the 16 repaired at a shop (fairly cheap) and keep it on the boat as a spare. <br />_________________________________________________ When you increase pitch the RPM drops 100 to 200 so if Ben is only getting 4050 at WOH he will have even less RPM with a 19" pitch.If repairing his prop and tuneing the engine does not improve the RPM Ben will have to come down in pitch.

 

[ILIKEROSTERTAILS]

Re: Boat Prop Selection Help

Ok Thanks,<br />Ben<br />P.s is there a certin brand I should go with?