high 5 prop? on a 4.3

Joined
Jun 22, 2011
Messages
6
hi guys, what would you recommend? 2008 larson senza 18' with a 4.3 merc came with a stock 23 pitch prop.... dog out of hole, cruising speed is good. i want more pull for tubing and skiing with keeping some top end. ive been told about the "high 5" prop? and just wondering if anyone here has any experience with this prop? and how it worked. i was thinking of going with a 21 pitch.... i would love to hear any opinions on this prop or better suggestions... thank you....

BMC...
 

jkust

Rear Admiral
Joined
Aug 2, 2008
Messages
4,942
Re: high 5 prop? on a 4.3

I always wonder why do boats with only a 4.3 come with a 23 pitch prop from the dealer. A really light stingray I can see so they can boast high top speed numbers but a middle of the road for weight Senza is absolutly going to dog out of the hole with a carb 4.3 and a 23. Before I ever even considered an expensive prop like a high 5, I'd try a 19 pitch 3 blade. Even on my sig boat that weighs 10% more than your Senza dry with its 4.3, a 21 does a respectable job while a 19 would really satisfy. To get the best of all worlds, I'd find a shop that will let you swap props until you find the one that suits your needs. What are your WOT rpms with that 23?
 

pat8839

Petty Officer 1st Class
Joined
Apr 18, 2008
Messages
270
Re: high 5 prop? on a 4.3

I have a 2006 Bayliner 195 4.3L (not sure of her exact weight but I think it is around 2,800lbs dry) that came with a 19* aluminum prop. At full throttle she would over rev so when I went to the high 5 I got a 21* and now there is no danger of over reving. It does a great job with hole shot and I would certainly reccomend it!
 
Joined
Jun 22, 2011
Messages
6
Re: high 5 prop? on a 4.3

I always wonder why do boats with only a 4.3 come with a 23 pitch prop from the dealer. A really light stingray I can see so they can boast high top speed numbers but a middle of the road for weight Senza is absolutly going to dog out of the hole with a carb 4.3 and a 23. Before I ever even considered an expensive prop like a high 5, I'd try a 19 pitch 3 blade. Even on my sig boat that weighs 10% more than your Senza dry with its 4.3, a 21 does a respectable job while a 19 would really satisfy. To get the best of all worlds, I'd find a shop that will let you swap props until you find the one that suits your needs. What are your WOT rpms with that 23?

ya i thought the 23 was an overkill aswell.. i threw on a 3blade-21 i had and it made a way better hole shot with 4 people... the 23 took alot longer to plain with 4 people. unfortuneatley here, no shop is willing to hand out there props to try... so im hoping for some good info on these before i make that purchace... i have found a used one here for 400, so i hope these are good props for my boat..

BMC
 
Joined
Jun 22, 2011
Messages
6
Re: high 5 prop? on a 4.3

I have a 2006 Bayliner 195 4.3L (not sure of her exact weight but I think it is around 2,800lbs dry) that came with a 19* aluminum prop. At full throttle she would over rev so when I went to the high 5 I got a 21* and now there is no danger of over reving. It does a great job with hole shot and I would certainly reccomend it!

is the hole shot comparable to your 3-19 you had on before?

BMC
 

jkust

Rear Admiral
Joined
Aug 2, 2008
Messages
4,942
Re: high 5 prop? on a 4.3

ya i thought the 23 was an overkill aswell.. i threw on a 3blade-21 i had and it made a way better hole shot with 4 people... the 23 took alot longer to plain with 4 people. unfortuneatley here, no shop is willing to hand out there props to try... so im hoping for some good info on these before i make that purchace... i have found a used one here for 400, so i hope these are good props for my boat..

BMC

Well, there are a couple of those shops around my area but the downside is you pay full retail and then some if for no other reason it is a marina and the markups are steep. I've seen a few on CL as well this season used for around 250ish as well this spring. If you've ever read up on boat manufacturers and how they prop for their tests, even the prop guru's employed by the manufacturer try a good number of props. I can only imagine the hit and miss ratio when your shooting in the dark meaning how much performance is left on the table you may never know existed. There are exchange programs here as well but the wait time between exchanges would kill me.
 

Tail_Gunner

Admiral
Joined
Jan 13, 2006
Messages
6,237
Re: high 5 prop? on a 4.3

I boats has a stilletto BayPro 2 in a 4 blade...20 pitch should do the job quite nicley...Can you post your results from the 21 such as speed and rpm along with gear ratio..its stamped on your outdrive
 
Joined
Jun 22, 2011
Messages
6
Re: high 5 prop? on a 4.3

I boats has a stilletto BayPro 2 in a 4 blade...20 pitch should do the job quite nicley...Can you post your results from the 21 such as speed and rpm along with gear ratio..its stamped on your outdrive

this weekend i should get a chance to get out and run the 3-21,3-23,and 5-21high5... i will post results

BMC...
 
Joined
Jun 22, 2011
Messages
6
Re: high 5 prop? on a 4.3

finally got out to test the props....full tank, 4people in boat.... stock 23p-3blade ocm that came with boat- slow out of hole, 4500rpm 47-48mph WOT..... 21p-3blade- hole shot better, 4900-5000rpm 43-44mph..... 21p high 5- hole shot felt the same as 21-3blade, 4900-5000rpm, 45mph..... i still want more hole shot, but want to keep the 45ish mph..... so? is it ok to run 4900-5000rpm?? would a 4blade prop be better for what i want?? what pitch?? 19-20-21-22?? do trim tabs help that much for hole shot??? now what to do??? lol..... thanks

BMC...
 

durdy

Cadet
Joined
Apr 14, 2008
Messages
26
Re: high 5 prop? on a 4.3

Dear Black Max Canada,

I have a very similar boat to yours (Larson 180 with the 4.3) and I too found the stock 3-23 prop lacking at the low end. I did a fair bit of trial and error and Internet research before ending up with my current setup. Based on what you've written I'd say a 4 blade is what you're after. I've tried four different props. Here are two that I've liked: the Solas 4x21 and 4x19.

I currently run the 4x19 since I spend most of my time towing tubes and skiers with a fairly loaded boat. Low end and mid range acceleration is good. The boat planes really well at low speed. The prop will over-rev at the top end (45+mph?) but I rarely run anywhere near there so it's not a problem.

I felt the 4x21 didn't give up too much to the 4x19 and cruised much better - lower RPMs at comfortable cruising speed. Also the top end was pushing 50 and stayed within the recommended rev range. This may be a better fit for you.

I ordered my props from iBoats. Delivery to Canada was quick and cheap.
 
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