suntimes

Well, at least you know the boat hull has the speed potential! How did the compression test turn out? Hopefully the computer scan will show a bad sensor or something...Maybe you can get the full throttle rpm read from the computer so you know what the actual engine speed at WOT is (in case your tach is off).

By the way, the magazine article said 4500 lbs dry weight, but the mags don't always report the most accurate data for that stuff.

HardmanGT

Compression was 155-160 at each cylinder cold.

Fuel pressure key on, engine off is about 45 pounds with the pump running. Pressure immediately drops off to around 38 pounds once the pump stops running. What should fuel pressure be at speed?

Plugs are replaced, wires tested fine.

I have 2 people believing that the injectors should be pulled and cleaned.

Pretty much all I have at the moment.

Still waiting for an appointment to get the scan from the marina.

suntimes

Sounds like the basic engine is solid. I don't think the fuel pressure will drop much as you are running. If so, then there might be a restriction in the fuel lines/pick-up. You should also check your fuel vent line is open, but you would probably already have noticed a problem when filling up.

One other thing to check with engine off: is the throttle plate open all the way when you put the throttle lever down?

Hope you find something in the scan...

HardmanGT

Checked the plate and it is fully open when the throttle lever is fully open. I may pull the injector tonight and drop them off to a place that cleans and flow tests them. Other than a sensor issue that I can't find until the scan, I'm at a loss.

HardmanGT

Suntimes,
Any chance I could buy that issue from you or get you to scan it for me?

suntimes

I can scan it--just PM me your e-mail...

HardmanGT

Well I think that this package is just slow from the factory. Nobody seems to have any test results for the Mag/B1 option, only for the HO/B1X.

In talking to Rinker they advised that the HO and 500efi options used the labbed B1 24 prop and spacer, not the standard B1 24 prop that I was equipped with.

So in conclusion, the differences between the extra 50 horses, extra 500-600 RPM and labbed prop with spacer are probably the reasons for my "missing" speed.

I spoke to Ray at Raylar and will be adding a 103 cam and having them flash the ECU. I also have an email in to BBlades for a prop.

Thank you all so much for your advice, knowledge and patients!

Knot 4 Me

I'm very familiar with this boat and Rinker's in general. How did the boat sit on the trailer when you found it? Was the hull overhanging the bunks? Make sure you do not have any trailer-induced hook in the hull. Being that it is a Rinker, you could have a heavy boat from them.

Our local marine dealer has sold them for years and you would be amazed at how much difference in weight there can be between identical model/equipped Rinkers. A friend of mine is a Merc tech that worked at the dealership for a few years. He would show me cutouts of the hulls where he would add Corsa exhaust. There was never one cutout that was the same thickness side to side or boat to boat. Some cutouts were really thick and others almost paper thin. My buddy and I bought new 232 Rinkers in 1999 with the same motors. My boat was a full 2 MPH faster on GPS. Obviously the workers laying up the boats were not much into quality control!

The 496 MAG can turn 4,800 RPM. You are giving up some speed there most likely. I have the same motor in my currrent boat and I definitely run faster at 4,800 RPM than 4,500 RPM. Brett from BBlades worked my props. I would start with Brett (assuming your hull is not hooked) and work with him on a prop to get you turning 4,800 RPM. Also, did they do a leak-down test when they did the compression test? A leak-down test will be a better indicator of the health of the motor. Where all the plugs firing when you pulled them? It is hard to hear a miss in these motors with wet exhaust.

This boat should run upper-50's GPS with a non-labbed prop.

HardmanGT

Best I have been able to acheive has been 53 GPS at around 4600 (hard to tell accurately on the gauge)

Attached is a scan from the 2002 article that was sent to me and a shot of my gauges at speed. I'm pretty much right there at 4500 rpm with the HO and 500.

4mulafastech

I just got off the phone with my brother from TX. He has that exact boat (red) with a 496HO and turning a 24 pitch Bravo prop. The prop came from the factory labbed, but it was bumping the rev limiter. Had the prop modified to take a little rpm out of it (cupped) and now it turns 4800 rpm and he will run 65-67 mph GPS depending on load and conditions. That is around 10% slip.

As others have said, you definitely should be running faster than 53 mph if the engine is actually turning 4600 rpm. This calculates to 24% slip. You should be running about 10 mph faster at that rpm. Have you verified the tach is accurate? Maybe try and borrow a labbed Bravo prop. The engine power is good if it can turn up to 4600 rpm, so I would focus on the slip/efficiency issue. I think it was also mentioned to check the straightness of the hull. If it has a significant hook that can hurt efficiency. Good luck!