https://www.offshoreonly.com/forums/ You must be a Gold, Platinum, or VIP Member to participate in this section en Sat, 23 May 2026 09:01:56 GMT vBulletin 120 https://www.offshoreonly.com/forums/images/misc/rss.jpg https://www.offshoreonly.com/forums/ https://www.offshoreonly.com/forums/prop-talk/388044-prop-other-help-needed-28-saber-1989-a.html Fri, 15 May 2026 20:05:11 GMT I've had a hard time getting my Saber to run flat at speed. It has a bad porpoise that keeps me from dragging the tab at pretty much all speeds. Would like to be able to run WOT without having to drag my tabs. Unfortunately I've not been able to get any real top speed numbers to calculate current slip % because I'm having to drag my tabs. It has twin mercury black 502/415 EFI mags with standard bravos 1.5


It is a 1989 28 Saber, hull #3. The first one made with twin engines. It's like the twin engines were squeezed into a narrow 8ft beam single engine boat. The chines are tiny, about 1 1/2 inches wide. Subsequent models were changed to widen the chines and engine bay quite a bit. There is a ton of rocker in the hull, like 2 inches worth, the corners of the hull don't even sit on the trailer bunks there is so much rocker and it begins about 2ft forward of transom.


Initially I tried a pair of bravo 4 blade 26p props. The porpoise was terrible. When I say terrible I mean it was violent and would develop faster than I could react. I put on 3 blade mirage props 25p and saw significant improvement, porpoise developed slower so I could react to it, but still too violent at speed when trying to raise the tabs. The prop center shaft is at 6 1/2 inches below the hull, I'm certain. The boat is very sensitive to changes and weight it seems. I am going to play around with center of gravity (weight) and turning props in; the props are currently spinning out. We are going to try moving weight forward or back. Original power was 454 merc 365hps I think and original owner said it didn't have these kind of issues. I bought it as a completely rigged hull less motors. The only change in weight from stock setup is that the exhaust manifolds are now IMCO so aluminum instead of cast iron. There are also two separate 45 gallon fuel tanks that sit in the cabin on top of the stringers just in front of the cabin bulkhead held in place by an extra bulkhead on the forward side of the tanks. Any help would be greatly appreciated and thanks to all who contribute on this site. ]]> Prop Talk TexomaPowerboater https://www.offshoreonly.com/forums/prop-talk/388044-prop-other-help-needed-28-saber-1989-a.html https://www.offshoreonly.com/forums/prop-talk/388026-checkmate-280zt-prop-choice.html Wed, 13 May 2026 20:08:55 GMT Guys,

A buddy picked up a 280ZT with the 502MPI for cheap last fall. It seems to be a bit short of expectations (not bad). We had it strung out to ~4750RPM right at 60GPS. It currently has a B24 prop on it and I'm wondering if it' the right prop. I'm told a Mirage Plus 23 might be a better choice. Any insight?

Thanks. Brad. ]]> Prop Talk Brad Christy https://www.offshoreonly.com/forums/prop-talk/388026-checkmate-280zt-prop-choice.html https://www.offshoreonly.com/forums/prop-talk/387956-merc-ventera-prop-info.html Tue, 05 May 2026 13:53:49 GMT Would like to hear how this Ventera performs vs The REVOLUTION 4 and The bravo models? Would like to hear how this Ventera performs vs The REVOLUTION 4 and The bravo models?
]]> Prop Talk JaniH https://www.offshoreonly.com/forums/prop-talk/387956-merc-ventera-prop-info.html https://www.offshoreonly.com/forums/prop-talk/387856-formula-242-high-x-dim.html Fri, 24 Apr 2026 06:32:40 GMT Hey Guys, Bought this boat and did a complete refit. Boat was without power and now its powered by a 502 MAG MPI with stainless manifolds. X-Dim is about 1.5 inch higher as original. Bravo1 drive, 1.5 Ratio. This was the first test. I have now a Revoloution 4 23p Prop on it. Boat accellerates... Hey Guys,
Bought this boat and did a complete refit. Boat was without power and now its powered by a 502 MAG MPI with stainless manifolds. X-Dim is about 1.5 inch higher as original. Bravo1 drive, 1.5 Ratio.
This was the first test. I have now a Revoloution 4 23p Prop on it.

Boat accellerates and gets on plane perfectly.

2800rpm - 32 mph
3300rpm - 40 mph
3900rpm - 47mph
4300rpm - 55mph --> this is highest speed

This is trimmed ALL THE WAY DOWN. If i start trim her up, i get a massive rooster tail but the boat slows down. I can trim her up to 4800 rpm and she gets 50mph. Feels like the bow does not lift at trim.
Boat has no tabs, driven on a river in fresh water, no chop.

Any suggestions how to improve?

Thanks!


]]> Prop Talk AP700 https://www.offshoreonly.com/forums/prop-talk/387856-formula-242-high-x-dim.html