Questions on Prop

[Bry21317]

I am trying to find a better prop to get my RPMS in the correct range. My boat is a 94 Crownline 19 Foot Bow Rider with a Mercruiser 5.0 liter and an Alpha 1 Lower Unit with 1.65 Gears, thru hull exhaust. The boat weighs 2900lbs from NADA.

Here is what came on the boat a 13.75 X 21 Michigan Wheel aluminum. It was pushing the boat to 5200 rpms and just over 50mph by GPS. This run was only me and the wife on the boat with it loaded with our stuff. Lower than Half a tank of gas.

I have used alot of Hustler props in the past and had great luck with them, so I tried a Hustler 14 1/4 X 21 and it dropped me to 5000 on RPMS. This run was this past weekend with the boat loaded up and 5 adults and 2 kids. The lake was very choppy and rough due to the wind and lots and lots of boats out. I had almost 3/4 tank of gas also. I didn't do a top end run, but I was up in the Mid 40s a few times cruising for sure with the boat fully loaded.

With the Hustler Prop the boat definetly came out of the hole a little faster and had alot better grab when trimming the motor up, it didn't slip as easy as the Michigan wheel did. I was able to get the motor high enough, with the full load that it was shooting a little rooster tail, without the prop slipping.

I am not sure what to try now, but my RPMS are to high. I purchased the Hustler prop as they are pretty cheap and I had good luck with them in the past on my old boat. I also wonder if Stainless would help, but I am trying to get my RPMS closer to where they should be, before I try to test any stainless.

Do you think I should try a 23 Pitch Hustler?

Thanks,
Bryan

 

[Bondo]

Re: Questions on Prop

Do you think I should try a 23 Pitch Hustler?

That would be the Most Logical next Step..........

 

[JJJ]

Re: Questions on Prop

Or you could try a Solas 1511-153-21, the extra diameter helps on a heavy boat and they are only $107 from Iboats.

I run the 19 pitch version on our 4.3 Merc Cobalts and it is a great prop for the price, in fact I took off my 4 blade stainless for it.

 

[Bry21317]

Re: Questions on Prop

Ok,
I finally got the 23 Pitch Hustler, and took the boat to the lake this weekend. I really got to run it hard on a large lake. I put the 23 Pitch Hustler on and put the 21 pitch Hustler in the boat. So they were the exact same brand props to limit the differences of brands or anything else.

With the 21 pitch I can still get up to about 5000 rpms with the boat fully loaded running in the 50s. This was with 5 people on the boat. Hole shot is great, and everything is good, acceleration, midrange, top end.

When I ran the 23 pitch prop, my RPMS dropped alot. It came out of the hole slower and still felt good, but it seemed like I had alot of spray coming up in the back like the prop might not be gripping as good as the 21, when I was at WOT. I could only get up to 45 with this prop, with 3 people on the boat. My RPMS also dropped, fully trimmed to about 4300.

So needless to say I put the 21 pitch back on, as it was like night and day difference after I ran the 23 Pitch for about and Hour Trip down the lake. It was like putting a turbo charger on the boat, lol to me. With the extra power on hand ready to go, when you touched the throttle with the 21.

Does anyone know why going from a 21 to a 23, I lost at least 700 RPMS? Nothing else changed, both props were brand spanking new, no dings no paint missing at all. Both Torqued down to 55lbs, and both spun freely.

Thanks,
Bryan