what prop ????

[Brandon Spurlock]

i have a 91 subird corica 198 with a 4.3 the prob i have is it has a 15x17 prop and it is only going about 35 to 38 mph at 5,500 rpm with 4 people in the boat. what prop should i run. i was told that 45 to 50 mph is where the boat sould run . any help would be great.

 

[Brandon Spurlock]

Re: what prop ????

my prop is not in the greatest of shape

 

[Tail_Gunner]

Re: what prop ????

Hello again, are you looking at or for alum or ss...

 

[Brandon Spurlock]

Re: what prop ????

i dont know, all i do know is i am going to have to do something. i was told that you can have props fixed. i might look into that. any help would be great.

 

[dsmmace]

Re: what prop ????

Switch to a 21 pitch 3 blade and retest, your engine should not rev past 4800 rpm if it is stock.

 

[walleyehed]

Re: what prop ????

A good place to start is verifying the tach for accuracy.
In my experience we have set up 4.3's for around 5000rpm.
A good all-around performer that usually shows above average numbers on that style of rig is a stiletto BayPro II, but not knowing the actual make, model and condition of your current prop makes it hard to say 18 or 20P.
5500 won't hurt you but it isn't gaining anything either other than hellish hole-shot. If you can pull a P/N from the prop, we'd know a bit more about the design.

 

[Brandon Spurlock]

Re: what prop ????

i would say the prop is a stock, the numbers off from it is 391200
thanks for any input

 

[Brandon Spurlock]

Re: what prop ????

heres some info on the prop i found

V6-8 OMC Aluminum 15 in. diameter x 17 in. pitch.
Recommended for 22-26 Cruiser boats at speeds of 30-42 mph.
New genuine Evinrude BRP OMC in Original Box.
Old P/N 391200. New P/N = 763467
NOTE: Superceded by Part Number # 763467.
Three hub exhaust. 3 blade. Aluminum.

For use with the following engines:
V-6 150-235 HP. and 2.6 litre.
V-4 with V-6 Gearcase, 100-140 HP.
V-8 250-300 HP, and 3.6 litre.

 

[Tail_Gunner]

Re: what prop ????

heres some info on the prop i found

V6-8 OMC Aluminum 15 in. diameter x 17 in. pitch.
Recommended for 22-26 Cruiser boats at speeds of 30-42 mph.
New genuine Evinrude BRP OMC in Original Box.
Old P/N 391200. New P/N = 763467
NOTE: Superceded by Part Number # 763467.
Three hub exhaust. 3 blade. Aluminum.

For use with the following engines:
V-6 150-235 HP. and 2.6 litre.
V-4 with V-6 Gearcase, 100-140 HP.
V-8 250-300 HP, and 3.6 litre.

have a 91 subird corica 198 with a 4.3 the prob i have is it has a 15x17 prop and it is only going about 35 to 38 mph at 5,500 rpm with 4 people in the boat. what prop should i run. i was told that 45 to 50 mph is where the boat sould run . any help would be great.
__________________
Theres 3 types of boaters,
those who can count and those that can't

17@5500
18@5300
19@5100
20@4900
21@4700

add a 100 for the 4th blade 20 nets 4800...Not much avaible there aside from the Baypro 11 and i agree with WH its a fantastic prop for both speed and midrange performance.. if its in your budget you wont be unsatisfied is the word..

http://boatpropellers.iboats.com/OM...23007/?**********=589057736&*******=728959602

http://boatpropellers.iboats.com/OM.../6765/?**********=589057736&*******=728959602

The second is another great prop...Your performance numbers reflect a heavy loads both those props will run with and without loads in your engines rpm band

The ss 20 should net 4700 under big loads and the alum 4600 both will work fine..Now most of this post is done on how its supposed to work with pitch..What happens when the prop is on your boat...Things might vary but i think your going to be ok

 

[Brandon Spurlock]

Re: what prop ????

thanks for the help might get the 2nd one

 

[Brandon Spurlock]

Re: what prop ????

i was reading that if you go from a 3 blade to a 4 blade you need to drop one '' of pitch. so if i was looking at a 21'' 3 blade prop i should go to 20'' 4 blade prop

 

[Tail_Gunner]

Re: what prop ????

i have a 91 subird corica 198 with a 4.3 the prob i have is it has a 15x17 prop and it is only going about 35 to 38 mph at 5,500 rpm with 4 people in the boat. what prop should i run. i was told that 45 to 50 mph is where the boat sould run . any help would be great.

4 people (heavy load) 17@55
17@5500
18@5300
19@5100
20@4900
21@4700 Running @ 4700 with a load of people is right near the top.. running a 3 blade 21 will do just fine for top end speed...Now using a 4 blade 21 will give you lower plane speeds and better hole shot the cost 100 rpm..4600 and maybe 1-3 mph.

I suspect or hope that you will not run @ 4600 to much very little i hope...That motor is a pushrod rod....There happiest at 3-3500 rpm where 80% of boating occurs..... WOT is a bit taxing on the valve train..4600-4800

Again either way you should be fine...choosing the 21 with 2 people aboard show max you out...But if you choose a 20 again its much better than the 17

Besides that is a older motor...take it easy on the old girl...4600 wot is kewl..