Hole shot sluggish

[Meleagris1]

I’m running a 21’ Phoenix. My last Phoenix had the same hull with an SHO, now the Merc. Just broke in the Merc over the course of a couple days. Two questions:

1) I noticed with a full gas tank it really killed the hole shot, which was only ok to begin with. It definitely doesn’t pop up on pad like the boat did with my SHO. Mid range and top end seem fine, a bit slower, but it’s mainly the hole shot. I always ran my SHOs with a 24P Fury 4 with all PVS holes plugged. I took the prop off my SHO so same exact prop on the boat now. Drill out some PVS plugs?

2) The motor vibrates (you can see wheel shake) between 1800-2400 RPM - then goes away and otherwise no shaking and smooth running. Any thoughts on that?

[krindgen]

Yeah, I might mess with the plugs. Maybe start with a 1/8 in each and go from there. That and play around with your weight distribution.

[Jbass123]

This might or might not be an issue, but I don’t think you can assume that the best prop for the SHO is also the best prop for the Mercury.

[Meleagris1]

Thanks guys - Im hoping drilling a few holes in the plugs will help - the prop has a lot of plugs - 8 so maybe try 1/8” in 4? I’ve got no idea how much of a change this will make. The weight distribution is even now and a little light compared to tourney season.

I realize that this prop may not be perfect but my SHO liked the 25p Fury 4 and the 24P was good but kept me close to the limiter so tye 24 Fury was a good starting point and a lot of people love it on this hull, including my dealer owners personal boat. I could go with a 23P if the drilling of the vent plugs doesn’t work. Was surprised because neither of my last 2 SHOs were this sluggish even when I went to bigger props.

[krindgen]

I hope someone else will be along that can confirm the plug hole sizes. When I was messing with my new Razor it was suggested that the best tuning was to have all plugs the same size around the barrel. To do it again I would have bought all solid plugs, 8 on that prop, and start drilling holes one at a time. When I got to the correct venting I calculated the amount of venting and the size hole for each of the 8 plugs. I first went out I had no plugs and the boat would just barely plane with all holes open.

[5keepers2]

I suggest you try a 23 Fury or Tempest. See if you can borrow one from a friend. Big difference!

[mactlman]

23p fury 3 or a bravo1 better props to try. i have vents wide open and no issues on my fury3 sure you reaching 100% linear demand on throttle?

[Meleagris1]

I’m going to pick up a Fury 4 23P to try - I just put a 24P Fury 3 with open vents on to see how that runs and if the vibration is gone.

[EuropeanAM]

Vibration may be due to the way the hub was installed. Remove and if it's an SSR Hub Kit, see the FAQ Section for suggestions on proper installation.

REALLY need to get a lower pitch prop on that engine and get it spinning up there at or north of 6K RPM's.

[Meleagris1]

Thanks Don - I actually bought the new SSR hub from you. I read the instructions - including torquing and correct orientation on the washers etc. I just pulled the hub and reinstalled it though in case there was an issue with the way I installed it the first go around - the FAQ was helpful. I do plan on a 23P to try.

[Jasonrs]

I have a 721 with a 250 merc 4s. I run a fury 3 24p with all plugs open. Hope this helps

[Meleagris1]

Just to follow up on this, I removed all 8 PVS plus from the Fury prop and it completely eliminated the hole shot issue. Boat jumps up on pad now. I bought a 23P just to get engine RPMs above 5750 but otherwise running great.

Regarding the SSR hub - I reinstalled it and also tried the SSR from my backup prop and it still vibrates at 1700-2000 RPM. Not sure the hub is the cause but I’m going to try the Merc racing solid hub and see what that does.

[EuropeanAM]

Keep in mind that some of that vibration may simply be due to the extremely heavy load on the engine (well above idle, but really not planed off, so pushing an incredible amount of water).

[Meleagris1]

After reinstalling the SSR hub (tightening prop nut in 1/4 intervals based on # of blades) and then trying a second SSR hub I bought as a backup, I still had this vibration @ 1700-2000 RPM. I agree its when pushing hardest but still can't be right, I think any owner would raise this to their dealer if they felt this kind of shudder/vibration and I've never experienced anything remotely similar on my last two boats. After discussing with my dealer they recommended trying the Mercs solid racing hub. The good news is that the racing hub eliminated the vibration. Not sure what the issue was but I guess my motor just does not like that SSR hub.

[EuropeanAM]

Interesting. Thanks for reporting back and sharing.

[Frikster]

What hub is the solid racing hub?

[Meleagris1]

Mercury Part #8M0183487