1997 Baja Outlaw top speed issue
 

New to a 1997 Baja Outlaw 24 with a stock carbureted 454. Top speed at WOT is 46 MPH. RPMs are maxed at 4100-4200. Running a Mirage plus 23. Compression is around 120 in all 8. Had 2 people in the boat with half a tank of fuel. Checked the timing and that the secondaries are open. Not sputtering or running rough at all. Looking for some ideas on what could cause a loss in speed. I'm expecting low 60s with this setup.

Did you check compression with throttle wide open?

Was timing checked at idle and at 3000 rpm?

Yes compression tested with throttle wide open. timing checked at idle and 3000 rpm. Base rpm was 8 degrees btdc and at 3000 at 32 degrees. I did notice that the distributor on this is an automotive and not the thunderbolt. Not sure if that is relevant.

120psi is low.
Which 454 model ? 330hp ? Or ????
What elevation are you at ?
Have to ask for diagnostics : you familiar with trimming outdrive and tabs for speed ?

Here are some good speed comparisons on your 24 outlaw:
https://www.offshoreonly.com/forums/...p-speed-2.html

That speed is not right. Nor is RPM. Something is wrong for sure.

Had a 97 24 SST with 454 carbed motor. Ran like 65ish

Is this on GPS or through pito tube stock speedometer?

I'm no mechanic but if it was only speed I think it would be easier to diagnose. Not getting the right RPM is weird. But 4100 RPM seems to match the speed. maybe throttle cable adjustment?

I believe it is the standard 454 model @ 330HP not the MAG. Elevation is appx 900-950 AMSL. I am familiar with the tabs and trim. At the 4100 RPM I had the tabs all the way up so not a factor and was playing with the drive slightly above and below level.

I agree that the speed and RPM are not right. We were checking speed with a GPS not the pito tube. I will have to look at the throttle cable maybe I can adjust it slightly. The other thought was an issue with the drive binding. The previous owner hit something with the prop. (see attached) With this prop, I could not even get on plane. I swapped it with a Mirage Plus 23 we were able to get on plane. Is it possible something is binding up or causing resistence? Some others have suggested a fuel delivery issue. Most of my research suggests poor idle or sputtering if that was the issue. The motor on the hose sounds great. This is only an issue when we are in the water under load. I also read something about not being fully "in gear" simulating an effect of a transmission slip in a car
https://cimg3.ibsrv.net/gimg/www.off...f9aed94d08.jpg
https://cimg4.ibsrv.net/gimg/www.off...fcc5584488.jpg
https://cimg5.ibsrv.net/gimg/www.off...135d236847.jpg

Did you knock around on the transom or put a moisture meter on it before buying?

Yes I knocked around inside and out and did not notice anything soft or hollow, unfortunately did not have a moisture meter. I was concerned myself that the hull was waterlogged. I am planning on towing it to the local scrap yard to get a weight on it.

You are at 25% prop slip at those numbers...ought to be in the 10% range for that boat...SOMETHING is not right. Have you confirmed it is a 1.50:1 ratio on the outdrive? There's a little decal on the top, port side.

For comparison, I am running 52 - 54 mph with the same engine using a Mercury Marine Revolution 4 prop, 21" pitch. I love this prop because of the awesome hole shot it gives if I have people wanting to ski or wakeboard, and holds the turns incredibly well...far better than the Mirage Plus I have tried. So, yeah...bigger boat, different hull and all but still...you have something seriously not right. Maybe a 1.32:1 ratio? Or the prop is just junk OR the hub is spun...which I assumed you checked first but THAT might be the whole problem.