2001 280 SS still sick!!!

[mercmonster]

anyone else have a brand new 280 that sucks,,,it doesn't matter whether I run a 30" chopper or a 28" 4 blade it stops making horsepower after 7000... I can turn 7500 but no more speed...my top speed on my 1100 pound bullet is 91mph and my buddy with the same rig gps's 98 to 100 depending on weight...the only difference is he has a 20" shaft and mine is a 15" he also has a manual 14" jackplate and I run a Paralift hydraulic....Thanks in advance.....

[Techno]

Has your buddy driven yours? maybe it's his driving-or the para lift. If I remember right the paralift changes your setback too doesn't it? Can you set your prop height and setback to match his?
I don't know your #s but if 7500 30" =91mph then you have 20% slip. With the 28" it's 14%

If you want I'll trade you my '89 2.4 frankenmerc. It will probably suck just as well(did I phrase that right?) but I think your engine will work better for me. Seems a good trade to me.

[sosmerc]

Been thinking about your "situation" and wondering whether or not we really have apples to apples here. Just limiting the discussion to the engines for starters...does the 15inch motor run the exact same lower unit as the 20 inch (gear ratio, propshaft diameter, exhaust cavity opening, skeg length, etc.?) Do these engines run the exact same tuner and ECM? What is the weight difference? How many hours on each engine? (I've heard the 3.0 litres aren't really considered "broken in" until they get about 40 hours on them! So far we've just considered the engines....how about the boats? Been my experience that no two boats are really the same. Minor differences in bottoms (slight hook, or rocker, or not so straight edges, motors mounted not quite on center, slightly different placement of accessories, blah, blah, blah...you get the point.
Get your best numbers with your engine...carefully record all data including test conditions. Then install his engine on your boat with your prop and see how they compare. .....or have someone dyno test the engines under the same conditions....or simply install a "test wheel" and run each engine wide open on the trailer and see which engine spins the test wheel the highest rpm...that would be a quick, down and dirty way to compare the power output of each engine. (again, assuming each motor is running the same gear ratio, fuel and proper setup...synch and link, etc.)

[gtsmpuc]

Are the 280 SS's 3.0 or 2.5?

[sosmerc]

..the 280's are 2.5 so my comments about not really breaking in until 40 hours most likely does not apply. I was thinking about a ProMax 300 I was working on awhile back. However, the 280's do have a similar electronic engine control system similar to the Optimax (no mechanical spark advance, etc) so the fuel mixture and timing curve may be different during break-in period and then change automatically as the hours increase. I have worked on some Optimax engines, but not the hp 280 so my thoughts are pure speculation. I get the feeling we will be more at the mercy of the ECM's programming as new models come online. Don't forget that the manufacturers are allowed a 10% + or - variance in stated horsepower....hopefully Merc's hp division tries to hit the high side!

[fastbasser]

I have a 280 EFI SS on my Bullet. Mine runs strong up to the limiter. Bet you have the motor way too deep in the water.
I run low 90s with the prop deep in the water.
What prop are you runnin? How high over the pad is your propshaft?

Drop me an email. We can compare notes.

Fast Basser