can any one help me to understand

[bruceb58]

Re: can any one help me to understand

according to the shop tach i can only go 5000 rpms no more then that

Very good news! That's because you hit the rev limiter.. Now the big question is do you go up 2" or 4" of pitch. I am thinking 4".

So was the boat tach indicating 6000 when your shop tach was indicating 5000?

I still would like to know how your boat ended up with a 1.81:1 drive ratio. Either the boat was sold for high altitude use or the drive got swapped at some point.

Keep in mind that if you do go to a 4 blade prop, its going to drop a couple hundred RPM or so so you may have to drop an inch of pitch to compensate.

 

[mannydvk11]

Re: can any one help me to understand

Very good news! That's because you hit the rev limiter.. Now the big question is do you go up 2" or 4" of pitch. I am thinking 4".

So was the boat tach indicating 6000 when your shop tach was indicating 5000?

I still would like to know how your boat ended up with a 1.81:1 drive ratio. Either the boat was sold for high altitude use or the drive got swapped at some point.

Keep in mind that if you do go to a 4 blade prop, its going to drop a couple hundred RPM or so so you may have to drop an inch of pitch to compensate.

the tach was going over 7000 rpms and the shop tach was at 485

now about how many inches ill go i really don't know anything about how that work i really want somthing where i can hit better speed and i don't feel like the boat is dragging i want to be able to cruse around idle speed with out having to feel like my boat is to heavy and i want to be able to step it up and fly lol wow i am asking for to much

 

[Tail_Gunner]

Re: can any one help me to understand

21p on a 24" cuddy 260hp.....Ummm id start with a 19..1.8 in mind

 

[mannydvk11]

Re: can any one help me to understand

21p on a 24" cuddy 260hp.....Ummm id start with a 19..1.8 in mind

rigth now is 17 lol i don't like it i want more

ok i have to ask one more time is my out drive bad for my boat is it to slow i really don't know what is the difference

 

[Tail_Gunner]

Re: can any one help me to understand

Your outdrive is fine...1.81 gearing is just a bit large...Now what no one is shareing you can run a larger prop for top end and still have a better hole shot than a 1.50..now calm down..:lol:

There's a message someplace there.....

 

[mannydvk11]

Re: can any one help me to understand

good what number is the one u have there i like that one

 

[bruceb58]

Re: can any one help me to understand

the tach was going over 7000 rpms and the shop tach was at 485

Were you at wide open throttle at 4850 or did you have more throttle to give it?

 

[trendsetter240]

Re: can any one help me to understand

Good that you got the RPMs sorted out. I will still recommend the same prop I originally did: 14x 21p 4-blade Solas Amita. I think you will be very happy with the performance.

 

[trendsetter240]

Re: can any one help me to understand

Were you at wide open throttle at 4850 or did you have more throttle to give it?

If the rev limiter is set at 5k then it cuts the spark until you drop 200-300 rpms so he was probably bouncing the rev limiter showing an average of 4850.

 

[mannydvk11]

Re: can any one help me to understand

Were you at wide open throttle at 4850 or did you have more throttle to give it?

yes i had more i calculate around 5300 rpms

 

[mannydvk11]

Re: can any one help me to understand

If the rev limiter is set at 5k then it cuts the spark until you drop 200-300 rpms so he was probably bouncing the rev limiter showing an average of 4850.

correct

 

[mannydvk11]

Re: can any one help me to understand

Good that you got the RPMs sorted out. I will still recommend the same prop I originally did: 14x 21p 4-blade Solas Amita. I think you will be very happy with the performance.

is it this one

Solas Amita Aluminum Propeller (2513-140-21) - iboats

 

[trendsetter240]

Re: can any one help me to understand

is it this one

Solas Amita Aluminum Propeller (2513-140-21) - iboats

Yes that's the prop. If you are buying that ensure that you select the correct hub for your drive.

 

[bruceb58]

Re: can any one help me to understand

The worst that could happen is that if it was too much pitch, you can sell it on ebay.

Here is one with free shipping
http://www.ebay.com/itm/Solas-Amita..._Accessories_Gear&hash=item46095e544e&vxp=mtr

 

[mannydvk11]

Re: can any one help me to understand

The worst that could happen is that if it was too much pitch, you can sell it on ebay.

Here is one with free shipping
Solas Amita Aluminum Mercury Mercruiser Propeller 1513 140 21 | eBay

so 21 o 19 will be a safe size

 

[bruceb58]

Re: can any one help me to understand

You want the one that will allow the engine to run at the specified RPM at full throttle. Keep in mind that will change if you want to use the boat with more load in it or at a higher altitude. Worst thing you can do to an engine is lug it. If you can't reach the specified WOT RPM, then you are lugging the engine.

 

[mannydvk11]

Re: can any one help me to understand

You want the one that will allow the engine to run at the specified RPM at full throttle. Keep in mind that will change if you want to use the boat with more load in it or at a higher altitude. Worst thing you can do to an engine is lug it. If you can't reach the specified WOT RPM, then you are lugging the engine.

OMG now am so confuse lol this is a big decision for what i see if i get the wrong one i will be in the same situation

 

[trendsetter240]

Re: can any one help me to understand

Either a 19p or a 21p will be better than what you have. What bruce is implying is that if the 21p is too much prop for your boat it will put excessive strain on the motor. When you get your new prop you need to run the same test with the accurate tach to determine what the maximum RPM for your motor with the new prop. If it's too low, say 4200 RPM then you will need a lower pitched prop.

You should be fine with a 21p prop, I'm 99% confident. Even plugging in the number for your boat into mercurymarine's prop calculator it comes up with 21p as the recommended size.

Choosing a prop like this isn't an exact science it takes trial and error.

 

[Tail_Gunner]

Re: can any one help me to understand

21 would make a 48 mph boat..Stands back a lillte so your ran a 17p with a 5000rpm rev limiter...at wot it wouild have been at a constant interrupt if you were really that under propped..Did you constantly here a slight miss at wot.

The truth is until you go there you wont know....

 

[mannydvk11]

Re: can any one help me to understand

Either a 19p or a 21p will be better than what you have. What bruce is implying is that if the 21p is too much prop for your boat it will put excessive strain on the motor. When you get your new prop you need to run the same test with the accurate tach to determine what the maximum RPM for your motor with the new prop. If it's too low, say 4200 RPM then you will need a lower pitched prop.

You should be fine with a 21p prop, I'm 99% confident. Even plugging in the number for your boat into mercurymarine's prop calculator it comes up with 21p as the recommended size.

Choosing a prop like this isn't an exact science it takes trial and error.

ok good ill try that one is there a way i can pic the Solas Amita at west marine i want to go to the keys on Saturday