Help with a new prop for Mercruiser 5.0

khall · Jun 9, 2013

Hi, my wife shredded my prop so I need a new one, and hopefully an upgrade...here is the info on my boat/prop:

Alpha 2 1.65 ratio
14 x 20p
Mercruiser 5.0L new last summer
2005 Larson Senza
Current speed with 4 adults was about 42mph maxed out before shredded prop

I upgraded to the 5.0L last summer and didn't really see much increase in speed/performance which was dissapointing. I already had some nicks and wear on my prop but maybe thats where I was missing out?? Anyway, looking to upgrade and get a higher max speed and better wake...about 50% pulling wakeboard/tube and 50% cruising time. If you need more info for a good suggestion let me know as I am completely new to replacing a prop..
Thanks

steelespike · Jun 9, 2013

Re: Help with a new prop for Mercruiser 5.0

Unfortunately speed without rpm isn't much help.Is the speed by gps? Your boats dry weight is about 3,000 lbs. What
is the hp of the 5.0.Is it new?What is your feeling of the overall performance with the 20" prop?
What did you up grade from and what was the performance before? How much is "not much difference" with the 5.0?
A prop aimed at max speed may be more difficult to maintain on the edge of wakeboard speed.

khall · Jun 10, 2013

Re: Help with a new prop for Mercruiser 5.0

Thanks, WOT rpm was running around 4800 with approx 750# of people and gear. The old engine was a 4.3L 190 hp, the current 5.0L is 220hp and yes, it was brand new middle of last summer. Honestly between the 4.3 and 5.0 I couldn't really tell any difference at all in the performance of boat...top speed, ease of plane, etc.

I am more interested in a prop that will plane faster and hold it better for boarding than one for top speed

Slip Away · Jun 10, 2013

Re: Help with a new prop for Mercruiser 5.0

Being a 14 x 20, I assume you have a 4 blade prop ?

SkiDad · Jun 10, 2013

Re: Help with a new prop for Mercruiser 5.0

i would say a 21 pitch would get you a little faster but you may loose a little out of the hole - but that probably won't matter for tubes or cruising. I'm am a bit shocked it won't go a little faster though - I would think at least 45 but maybe that boat is heavy.

khall · Jun 10, 2013

Re: Help with a new prop for Mercruiser 5.0

Yes it is a 4 blade. Well with two of us in the boat it would get closer to 48 mph

SkiDad · Jun 10, 2013

Re: Help with a new prop for Mercruiser 5.0

OK then the prop you were using put your RPM perfect - maybe you should just get the same? My neighbor has a Sea Ray with the 5.0 (260hp) and he runs 45 with the family along and 50 if just 1 person - He runs a 21 stainless but his rpm is a little lower than yours b/c the boat is bigger and heavy.

Slip Away · Jun 10, 2013

Re: Help with a new prop for Mercruiser 5.0

Our boat has a 5.0L 260hp Mercruiser. Boat is 3100 lbs dry. Wife and I , 1/2 tank of fuel, full cooler we get 56mph at 5,000 RPM anytime. Same numbers with 14-1/2 x 21 three blade or 14 x 20 four blade. The holeshot is much better with the 4-blade though.

khall · Jun 10, 2013

Re: Help with a new prop for Mercruiser 5.0

Ok, well maybe I will just stick with the size I've got then if theres not much improving it...would it be worth upgrading to a SS prop?

Slip Away · Jun 10, 2013

Re: Help with a new prop for Mercruiser 5.0

SS will cost you about another 2 hundred dollars. Performance will barely change. But the SS prop will look prettier.

21 celebrity · Jun 12, 2013

Re: Help with a new prop for Mercruiser 5.0

SS will perform better than the alum. just in the fact that it wont flex as much.. It's not just prettier:facepalm: if by chance your "wife" shreds the prop again it will be more costly with a SS prop due to the fact it won't fold the blades over and will send all the impact to the lower unit. Just my 2cents

Help with a new prop for Mercruiser 5.0

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