Parker 2801 Prop Question

[GoodChance]

I know that there aren't many out there but I have a question for fellow 2801 owners, especially those running F225's or 250's.

What prop are you running?

Right now I have a pair of F225's. These are the 3.3L engines. Motors are set on an Armstrong bracket and motors are at the highest hole possible. I can see the anti-cavitation plate at cruise. Gear ratio of these motors are 2.0:1.

As you know, the boat has a 9.5ft beam, 21 degree deadrise and per Parker, the "real-world" weight is with 300 gallons of fuel is 7,650. I figure that I'm probably around 8,000 - 8,500 as tested with people and gear. Right now I'm running the Yamaha M-19 SWS prop. This in not the SWS II prop but the 2 are very similiar. Here are my current performance numbers:

At 3800 rpm = 29mph which translates to 14.5% slip
At 4,000 rpm = 31 mph translating to 14% slip
WOT - (with a 15 mph tail wind and with a 1.5kt current) 5900 rpm = 48.9 mph
WOT (against 15 mph wind and against 1.5kt current) 5500 rpm = 42.4 mph
Average of the above WOT - 5700 rpm and 45.7 mph = 11% slip

These numbers aren't too bad but I'm wondering if there is room for improvement? I'm thinking of moving to a 4 blade prop such as a Mercury Rev4 or the PowerTech OFS4 in a 17" pitch.

Plus, a point I should probably highlight (and this is probably most important) the bow likes to ride high and I'm constantly on the trim tabs to keep the bow down. Even in calm water, I must use ½ tab to keep the bow down. Several different owners of the 2801 have said the same thing to me. The boat just likes to ride "bow-proud". If it gets especially rough, I need to use a lot of tab and trim the motors down. I'm thinking that the 4-blade prop will do a better job of lifting the stern. Thoughts?

 

[shawnee83]

What size tabs do you have? Your numbers sound pretty good with your current props. There may be some room to tweek with props but I don't think a 4 blade or any other prop will be the ultimate solution. JMO. I'm kinda a broken record on this subject, but big trim tabs and or a Permatrim will likely do what your looking for. If you haven't used this yet, check out the link to see what other prop options you may have.

https://www.mercurymarine.com/en/us/pro ... #/step-one

2 Permatrims will run you about $300 and you could have them installed in a few hours. I did the Permatrim first and now doing the tabs. I probably should have done the tabs first though. Hope this helps.

 

[Aclax8]

Damn...was hoping someone would have some intel.

 

[shawnee83]

I thought my answer was reasonable Intel. Prop performance numbers are currently not bad. Props are not going to fix the porposing/bow high issue. Well to be honest, 4 blade props may help?? But not completely fix. Bigger tabs number 1 and Permatrim's number 2. Stern lift is what will help both bow high issue and maybe slight improvement to RPM's. There is only room for improvement of about 200 RPM's here which is why I think the porposing or bow high issue is the most in need of attention. This may not be the desired answer but at the end of the day, it's what will correct this situation. I didn't look up the diameter if the SWS 11 m-19. Here is a prop recomendation but not what I would do first, maybe last to tweek?
Mirage® Plus Stainless Steel 3 15.25 19 RH 13700A46
Mirage® Plus Stainless Steel 3 15.25 19. LH. 13701A46

 

[kidfreediver]

Yes what size tabs

 

[Aclax8]

More so meant experience with 4 blades on this boat...

I thought my answer was reasonable Intel. Prop performance numbers are currently not bad. Props are not going to fix the porposing/bow high issue. Well to be honest, 4 blade props may help?? But not completely fix. Bigger tabs number 1 and Permatrim's number 2. Stern lift is what will help both bow high issue and maybe slight improvement to RPM's. There is only room for improvement of about 200 RPM's here which is why I think the porposing or bow high issue is the most in need of attention. This may not be the desired answer but at the end of the day, it's what will correct this situation. I didn't look up the diameter if the SWS 11 m-19. Here is a prop recomendation but not what I would do first, maybe last to tweek?
Mirage® Plus Stainless Steel 3 15.25 19 RH 13700A46
Mirage® Plus Stainless Steel 3 15.25 19. LH. 13701A46

 

[GoodChance]

Here's an update on the prop experiments I've been running. As discussed above, I bought the Parker 2801 with a pair of Yamaha SWS m-19 props (pitch = 19") and they seemed to run OK although the boat was a little bow high. The boat has good acceleration and the motors had a WOT of 5700-5800 with a light load.

For several reasons, I bought a pair of Rev 4 17" and ran them on 2 - 100 mile offshore trips and hand-calculated fuel economy. Here are the results (these numbers are with 4-6 people aboard and 300-400lbs ice, 300 gallons of fuel):

4000 rpm - 27.5mph and 14% slip
4200 - 30 mph and 12% slip
4350 - 31 mph and 11% slip
WOT - 5900 - 44 mph and 6% slip
Overall fuel economy was 1.35 and 1.38 on two different offshore trips

Compare this to the 3-blade SWS 19" on a 100- mile offshore trip with similar load as above:

4000 - 29mph and 19% slip
4200 - 31 mph and 18% slip
WOT - 5700, 44 mph and 14% slip

Despite the 3-blade SWS having more slip (and less efficient), my overall fuel economy was 6.2% better with the SWS and getting 1.45 mpg. This tells me that the Yamaha F225 is working harder to spin the Rev 4. But the numbers also say that the SWS is a pretty inefficient prop with a heavy load.

From here: It seems like the 3-blade prop is the way to go with this boat/motor combination and as such, I sold the Rev4 props.
Right now I am running the SWS 19". I will probably have them balanced and tuned and verify that they are actually 19". But I will also be looking for a set of Mercury Enertia 17" props. I had great success with the Enertia on other boats and would like to see what they can do on this one.

 

[shawnee83]

17 Pitch? Seems awfully low given your RPM data with the 19's. Interesting data on the 4 blades. Did they seem to give you a little better stern lift and bow control? Just curious as many try them for that.

 

[GoodChance]

17 Pitch? Seems awfully low given your RPM data with the 19's. Interesting data on the 4 blades. Did they seem to give you a little better stern lift and bow control? Just curious as many try them for that.

I think that the motors like to spin a smaller pitch for optimal fuel economy so I think that a drop to a 17" but heavier-cup 3 blade Mercury Enertia will maintain the same/similar speed and allow the motor to work easier. Fortunately, Ken of PropGods lives 5 miles from me and I can easily try whatever props that he may have available.

In terms of the Rev4 and providing stern lift ......... I didn't see much improvement over the Yamaha SWS props. I know that many other people really like the improved performance offer by the REV4 but I didn't see it on this 8,500lb boat.

 

[shawnee83]

I've talked to Ken about props before and he seems to be very good. I will use him too when I get around to tweetking my prop set up. Let us know how the 17's do. Good luck.

 

[4byr]

Does anyone know if the permatrim has been used on the single Yamaha F350? I have just picked up a 2530 and want to add it.... sorry for the hijack of the post....

 

[shawnee83]

I've not specifically noted anyone on here that has used one on a single 350, probably because not very many people have one. That said, I think it would use the same model as mine in the pic. As far as being heavy enough construction I don't think you will have any issues as it's made of thick aluminum and very rigid. I personally feel it will be fine. As you can tell from my post, I'm a big fan of them as it made such a huge difference on mine. It really surprised me with the results as I was skeptical of this add on. I'm still adding larger tabs just because I think it will only make things better still? By the book, I should have done the tabs first then I may or may not have done the Permatrim? If you have a new 2530 then I think it already has bigger tabs than the older ones. I think 20" across? If that's the case, then just adding the Permatrim would be the ticket. If you end up doing it, post it and let us know how it works for you. Good luck.

 

[4byr]

My 2530 had old 12 x 12 "boat leveler" type hydraulics that were a bit twisted and didn't work. I have removed them in favor of the Lenco 12 x 18. I have the new ones on order and will have them in by next week. I was hoping to add the Permatrim based on the recommendations here and wasn't sure of anyone that had incorporated it to the F350. I have traded e-mail with Permatrim in the USA and they say they do not have anything to support the F350. I was hoping... I guess the lower unit is more robust than the lesser 300? In any event, I am hoping the tabs will be sufficient then...

Thx

 

[shawnee83]

The tabs will help for sure but I think the combo would probably be ideal. I would look at the difference between the 250 lower unit and AV plate and the one on your 350. If M9 Permatrim would matches up fit wise, I would think it would still work? Good luck with you project.