Slow to get on plane

[Brandon15]

3 vs 4 blade

I have a 17 1/2 foot regal open bow holds 8 people and has a mercruiser 3.0 which I think is under powered but I have a 19p on there now and would get on plane with 7 people but not really want to and now I bent the prop on rocks and looking for a new prop, should I try to find the same one or try a 4 blade with a 17p and hopefully get on plane fast with a boat full of people ???

 

[Brandon15]

I have a 98 regal bow rider 17’5 with mercruiser 3.0 boat holds 8 people but won’t get on plane have a aluminum 3 blade 19p on and played around with a few other props in aluminum and ss up to 21p and nothing really done good should I order a 4 blade and see how it works I need something to get out the hole quick and pull a wakeboard

 

[Rick Stephens]

The higher the pitch prop, the lower the motor RPM and power out of the hole. I ran a 15 inch 4 blade or a 17 inch 3 blade on my 17 footer when it had a somewhat tired 3.0L in it.

If you go out by yourself with the 19" prop, at wide open throttle (WOT) what max RPM do you get from the motor?

 

[alldodge]

What is your WOT throttle rpm with full load of folks and gear?

 

[Brandon15]

Sorry forgot to mention that my tach does not work

 

[Brandon15]

I’m sorry my tach don’t work so I really don’t know what the rpms are doing

 

[alldodge]

Need to get a hand held and see what the motor is doing

ALso notice your other thread where Rick has responded

 

[Leardriver]

A four blade prop gives you more blade surface area to help get big horsepower to slip less. You have the opposite of big horsepower A three blade is just fine.

 

[Rick Stephens]

I’m sorry my tach don’t work so I really don’t know what the rpms are doing

IMHO, get it fixed or risk buying a motor. Boat motors run at 100% load 100% of the time. If propped too high you are constant lugging which will damage a motor quickly.

You cannot prop a boat without knowing RPMs, and you won't get it right without also knowing GPS speed - your cell phone can download and run an app to tell you GPS speed.

 

[ahicks]

A 17.5' boat with 7 people aboard sounds like an accident looking for a place to happen. The kind of boat you read about in Coast Guard reports.

 

[nola mike]

Also need to know if this is a problem with the engine. If this is new to you, you need to check compression, make sure the hull isn't waterlogged, timing, etc

 

[JASinIL2006]

You can get a Tiny Tach for about $50 and similar less-known brands for as little as $20. That would let you get RPM at least.

Is this a new-to-you boat? I would wonder if any boat that size with a 3.0 would get on plane quickly when loaded up with people and gear.

 

[Brandon15]

I will have to look into getting a tach and what rpms do I want to be turning ?? The boat is somewhat new to me and it does get on plane decent and I’ve had 6 people in the boat and pulling a wakeboard, (small lake with no public boat ramp so no traffic or anything) But the prop I have on there got bent and looking to see if I should change the pitch or blades to try and help out some or just get the same thing I had, I’m not sure the diameter of that one but the prop has 48 78120 a40 19p stamped on it.

 

[Brandon15]

Thanks to the people with advice and I would like to know the problem with a 17’5 boat with 7 people aboard ? The boat is rated at 8 and most of the time is spent on a small lake with no public access so usually the only boat out there ???

 

[WesNewell]

Mercury prop selector suggest a 21P prop at 41 mph with a max load of 4000#, so if you're having problems getting on plane with a 19P prop, you've got other problems. Really big ones if that's an alpha 2.40 GR.

 

[Bondo]

and what rpms do I want to be turning ??

Ayuh,...... 4400/ 4800 rpms, without the extra 5 people in it,..... closer to 4800 the better,....

 

[Brandon15]

Does anyone know what diameter prop this is ? 48 78120 a40 19p

 

[achris]

Does anyone know what diameter prop this is ? 48 78120 a40 19p

It's 14", but the diameter is not the main concern. Get that pitch down! 19" with that engine in that boat with 8 people? You're going to kill that engine. I'd prop you at 15" (pitch) as the start point.

Chris....

 

[Brandon15]

Okay thank you I am looking for a tach and some different props to try out

 

[Brandon15]

I don’t think I have other problems Becouse I can get on plane with 7 people and even pull a wakeboard with 6 in the boat