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Posts: 14
| Hi,
Interested if anyone out there has a Recon 985 boat with the new Mercury Pro XS 200 4-stroke on it? Wondering what prop and prop pitch you are running and what the boat performance stats are with that. Specifically looking for WOT RPM's, top speed, hole shot/acceleration, etc.
Thanks. |
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Posts: 8
| I have this exact setup. I have a tempest ss 3 blade with 21 pitch. Top speed 58-59. Hole shot is instant. I don’t know the rpm but going fishing tonight and can check. Very impressive motor! |
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Posts: 14
| Wow! That's very different from what I'm seeing. I have a Tempest 19 pitch and it's only turning 5750 RPM and top speed of 54 mph. I initially tried a 21 pitch and the RPM's were 5550 and top speed 55. The hole shot with 19 pitch is decent, but was slow with the 21 pitch. RPM range for this motor at WOT is 5600 to 6200, so I need to get that up. Would have to go even lower pitch to do that. Something seems wrong. I would be very interested in hearing more after you take the boat out tonight. Check max WOT RPM and speed.
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Posts: 8
| Wot rpm 5500 and 56.7 mph. I lost a little speed after I dinged up prop on some rocks a couple weeks ago. Not terrible damage but definitely lost about 2 mph. I’m not seeing the slow hole shot that you were. My boat is up on plane almost instantly. |
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Posts: 14
| Yeah, prop damage can have a significant effect. And you're running a 21 pitch?
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Posts: 14
| Also, are these stats with only you in the boat, or a partner and gear as well? Do you have a kicker motor or anything? |
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Posts: 3469
Location: Elk River, Minnesota | Hiya!!
There are a few things that can make huge differences in how a particular motor pushes a rig. First and foremost, the mounting location of the motor. In most cases, when motors are mounted to the transom, they are mounted for the purpose of overall running (handling and "decent" speed) but usually that is not the most efficient location. Many times the motor is mounted 1 bolt hole up off the transom, and this usually means the anti-ventilation plate is under the water's surface, which is a huge amount of drag. The boat will turn really well, but just doesn't float along while at cruising speed or really lift out of the water at high speed.
If you can, level the hull to the earth, then level the motor to the earth and take a picture. Let's start with what the rear end looks like by comparing the hull to the anti-ventilation plate.
The second big issue that may be happening is not trimming enough. I am assuming you have found your numbers here based on just you and your equipment (3/4 tank of gas) trimmed to the best position you can for speed.
With that size of motor, a 21 tempest should push it along close to 60 as has been mentioned, so my gut instinct says there is something up with the set-up of the motor, prop and boat.
The prop itself....Do you have the vent holes completely plugged, partially plugged or wide open? If wide open, that might be too much ventilation, and the prop is not grabbing well enough for a great hole shot.
That boat is balanced quite well for weight on it's own so a 3 blade should be all you need. If you are in the twin cities area, I'd give you a hand as well...
Steve |
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Posts: 8
| 2 adults, full gear, 3/4 tank, 21 pitch. No kicker. Motor is mounted one hole up from transom as Steve had mentioned. |
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Posts: 14
| Steve,
Thanks for your insight and information. I'm familiar with the motor mounting height aspects and previously had my motor raised one hole from where it was from the factory. Now, my motor is in the 3rd hole from the top. AV plate measures 2" above the bottom of the boat. At speed and on plane with the proper trim, the AV plate is skimming the surface of the water.
Today I was out with myself and two teenagers in the boat each weighing about 140 pounds and my gear and 1/2 tank of gas. The best I saw was 5700 RPM and 55 MPH. This is with a 19 pitch Tempest Plus prop. RPM's are in the low range for this motor. Should be up near 6000. Theoretically I have to go down to a 17 pitch to get the RPM up where they should be. This just seems insane for this size boat and motor, and at that low a pitch I will lose top end speed. |
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Posts: 3469
Location: Elk River, Minnesota | Hiya,
The numbers you list are almost unreachable good. Prop slip by what you listed would be one of the best I have ever seen at 6.15% so I am thinking something might be off somewhere. This is going off of a gear ratio of 1.75:1. If it were the 1.85:1 lower unit, the slip would even be lower.
I am assuming you trimmed all the way up to the point of porpoising or blowing out, then touching back just enough to settle it down and catch for the numbers you posted. Take out the 280 pounds of people, and your speed would be a touch higher...
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Posts: 14
| These numbers were on a river moving with a current, so it may have aided it a bit. Regardless of slip percentage, the overall performance of the boat is not what it was when I had an Optimax on it, and not as good as other Recon owners running the Pro XS. It has no problem getting up on plane, but acceleration is not were it once was and top speed is down about 3 mph. This could be due to a lower pitch prop. I just find it odd that this motor is supposed to rev up to 6200 RPM, and even with a 19 pitch prop it only gets 5700. Everyone tells me this new Pro XS has such awesome torque and acceleration that it pushes you back in the seat when you take off. I'm not experiencing that. |
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Posts: 3469
Location: Elk River, Minnesota | Hiya!!
So then the question is...were the numbers taken going down river or up river? That can vary as much as 3 - 4 mph and can throw everything off so it is not accurate. 5700 is not all that far out of line with two extra people in the boat along with you, your gear and maybe some extra of the kids.
Is the side spray completely behind you and basically off the back 2 feet of the boat when trimmed and full speed or is it along the side of you?
How long have you had this motor? Is it fully broken in at this point?
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Posts: 14
| Thanks for the continued assistance. Those particular numbers listed were moving with the current. Against current I was 2 mph less and a little less RPM.
This is a new motor, but fully broken in. Have about 20 hours on it.
The spray is completely off the back. Pretty clean. No big rooster tail or anything like that. |
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Posts: 3469
Location: Elk River, Minnesota | The tail can be as high as the motor cowling and things should still be hooked up. Any higher and the motor is past parallel. You'd be able to hear it in the motor that RPMS go up, but speed does not. Some boats are heavy enough in the front for this to occur. My Ranger 617 is that way as the tank is up front in the bow.
Being the motor is not broken in....I would wait and retest when break in is fully complete. You cannot be too far away from that point I would assume...
I wouldn't be surprised with the tempest prop that you would be able to have the motor mounted in the top hole and it would still bite well and corner fine with a little trimming down. Hole shot would most likely be a little better as well when the motor is tucked in too. Less leg in the water at holeshot will get the bow pushed over faster on top of the water. Also, are your vent holes completely covered, open or partially? That can be a huge aspect in this as well.
One other thing to consider... take a straight edge and put it on the bottom of the hull with the edge coming past the transom. Is it completely flat? Is there a small gap in front of the transom edge? Is there a gap AT the transom edge? These also need to be checked. If the hull has a hook in it, it will not plane as well and the boat will always run really flat to the water increasing surface area and drag. With a hull that has a gap right at the transom but flat in front of it, the boat might have a tendency to porpoise. It is a really fine line...
Take an hour or so for just yourself, your gear and a full tank of gas to a lake big enough to open up and get to full speed for a bit. If you have different vent hole plugs, try them and see what they do both for holeshot and top speed. Lots of options yet to consider here... In most cases the vent holes should not be an issue at speed as the gasses are moving too fast to come out the holes, venting the prop. And...in your situation, I am guessing they are completely plugged given your numbers are accurate.
Also...every boat and motor combination will be different. even when the boats are made from the same mold, they will not perform exactly the same.
Steve
Edited by VMS 6/22/2021 8:31 AM
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