Bow Lifting Prop ?

[Slapshot]

I have read many of the discussions on props. This is what I have. 1999 Pulse 185, 5.5" CMC Manual, 150 EFI Evinrude, 25 Renegade 4 blade. So far runs. 59 mph GPS in light chop. My question, the boat really takes off with more trim. In addition, I can go beyond max rpm, even though it is a 25 pitch on a little 150. I keep reading that other guys have smaller pitch props with more speed. Will a lower pitch bow lifting prop like a 22 or 24 Raker (larger 3 blade) speed me up that much because of the bow lift effect. I know most of you guys runs Mercs, but is anyone running a 22/24 Raker on an Evinrude mounted on a Pulse 185? Thanks.

 

[Slapshot]

I have read many of the discussions on props. This is what I have. 1999 Pulse 185, 5.5" CMC Manual, 150 EFI Evinrude, 25 Renegade 4 blade. So far runs. 59 mph GPS in light chop. My question, the boat really takes off with more trim. In addition, I can go beyond max rpm, even though it is a 25 pitch on a little 150. I keep reading that other guys have smaller pitch props with more speed. Will a lower pitch bow lifting prop like a 22 or 24 Raker (larger 3 blade) speed me up that much because of the bow lift effect. I know most of you guys runs Mercs, but is anyone running a 22/24 Raker on an Evinrude mounted on a Pulse 185? Thanks.

 

['91 Starliner]

I am running a 22 raker on a 200 Gt Johnson on a 21 foot starliner bowrider. I am still fooling around with it and found that bow lift seems to be crucial to speed. I've got the boat running 62.3 GPS with the 22 raker 14.5 diameter, I also have a 14.25 22 raker that only got me 54.8 GPS so the 1/4" in diameter made a 7 MPH difference. I am also having problems with my motor right now so I think it has more to offer once I get it straightened out. I also have a cmc 5.5 jack plate and I am going to move it down a hole because I recorded my fastest speed with the jack plate all the way down and used trim to bow lift as much as it would go. Still playing around with it though.

 

[daren34]

it depends on your rpm's
less pitch = more rpm
the raker has more bow lift for shure
i might try a 24 first but you may have to go higher to keep the r's down
i had a diplomate with a 140 johnson and a 6" cmc the raker was the best prop that i found

daren

 

[daren34]

and 3 blade vs 4 blade
the extra blade will also hold down the rpm's

daren

 

[175checkmate]

If you are running a 25p 4 blade now and are able to go above your max rpm then going to a 3 blade smaller pitch will hurt ya.
It sounds like you current prop may not be a true 25p. It may have been worked on before.
Find a place that will allow you to try out a prop or has a exchange program. Start with a 25 raker and then adjust from there.

 

[Slapshot]

I only go beyond max rpm with the jack plate all the way up, and max trim. I still have good water pressure and the rooster tail is still not big at all (nothing compared to what I see behnd some bass boats). I just sense the boat has more potential because the bow lift makes such a difference (possibly 65 gps). I don't know of any shop that will let me try a 24 Raker. Thanks for the info.

 

[supergenius74]

I agree it's hard now-days to find a place that will just let you take a raker out for a test. A raker is definitly the way to go and bow lift is very important to speed, another way to lift the bow is to move any weight back to the stern or add more setback to you jackplate with extensions. Also try to calculate the weight of your boat, with passenger(s) and use an one of the online speed/prop calculators, just do a search and google and you will find one. If you know the weight of everything, prop HP, you can calculate the max speed and then plug in different pitches to see where your RPM will be. It will get close enough as to not waste your money on the wrong pitch.

 

[supergenius74]

I just ran some rough calculations and I'm surprised you hit 59, with that weight of boat you should only see about 55 max, and turning a 25p 4-blade would mean you only hit 4500 rpm with normal 10% slip, either your engine has more than 200 hp or you are jacked up so high that your prop is slipping really bad. Either way turning a 24p raker should be no problem.

 

[daren34]

on the diplomate that i had i replaced the old v-4 140 with a new looper v-4 140
turned a 20 pitch raker at 6800 rpm and a 22 raker at 6400 rpm
speed was about the same maybe a little faster on the 22
had a 6 inch cmc hydrolic jack plate
i tried a cou[le of different omc props but the raker was the best on the mate
almost no chine walk
the 6 inch plate made all the difference though

good luck finding a good prop
what rpm are you actually turning at best speed
you said 59 was top mph
what is top rpm for your motor
daren

 

[daren34]

on the diplomate that i had i replaced the old v-4 140 with a new looper v-4 140
turned a 20 pitch raker at 6800 rpm and a 22 raker at 6400 rpm
speed was about the same maybe a little faster on the 22
had a 6 inch cmc hydrolic jack plate
i tried a cou[le of different omc props but the raker was the best

 

[Slapshot]

Thanks for the calculations. My max rpm at top speed is about 5500. Ideal operating range is only up to 5250. That's why I thought if I got more speed earlier with more bow lift, I would never have to trim the motor as much (possibly preventing any slip as you suspect). As far as the motor, it does run very well, but I think it is stock. Even with a stainless SST (basically an aluminum replacment made of SS with more cup) I goes about 53-54 gps.