Mercruiser 5.0L rpm, Crownline manual and water in bilge!

[Sulley]

A friend of a friend has just purchased a 2000 Crownline 242 with a Mercruiser 5.0L engine. As they know NOTHING about boats I have been volunteered to assist, God help them!

We took the boat out for the first time on Saturday (it's being kept on the Thames at the moment) it started first time but the rpm seemed really high. Tickover was 1600rpm and at 4.4knots it was 2200 rpm. The engine just sounded really "busy" to me.

We have the 5.7L Mercruiser in our boat and we are 1000rpm less at these two criteria and much quieter.

Does this sound correct for the 5.0L and am I worrying unnecessarily? The engine has apparently just been serviced before sale.

The other thing is there is water in the bilge approx a couple of inches. Our bilges are always dry so it is also a bit of concern. I'm due back to my boat and theirs this weekend so I'm trying to find user manuals etc as well to try and help me. If anyone has any links that could help as well.

Thanks in advance, why did I get volunteered!

 

[jhr]

I have a 5.0 l Merc efi in my boat. Tick-over is about 700 rpm and it maxes out at about 4,500. To get 4.5 knots (admittedly in a smaller boat - 22ft) I need about 850 rpm.

Something's not quite right, somewhere

 

[gjgm]

could be rainwater, of course...

 

[dustywings]

Should definitely tick over lower something like 700. I would start by checking the cables and linkages before adjusting the tickover screw, could be sticking or kinked. As for the water unless it there is an obvious leak and it is getting deeper I wouldn't worry. Pump it out and mop up then see if it returns after a trip.

 

[Spi D]

EFI or Carb version?

According to the manual page 47
http://www.boatfix.com/merc/Owner/gas/86419501.pdf

it should idle 600 rpm in neutral and reach 4600-5000 at wot

It sounds as if something isn't right and I'd suggest a call to the seller and/or the person who did the service.

EFI's idle cannot be adjusted, but else make sure the idle is adjusted correctly and detach the cable from the carb to see if it's actually resting on the adjustment scew.

 

[Wiggo]

Well, if it's only making 4.4 knots at 2200 rpm, I'd guess it's got a hopelessly wrong prop on there. Either that, or there's no prop at all, and it's just the exhaust gas that's shoving it along at 4 knots.

 

[Spi D]

If prop has FloTorq hub check if all parts are fitted..

 

[oGaryo]

does it rev high at idle when out of gear? i.e. the 1600rpm is when the rmeote is in the centre position

 

[Sulley]

It's an EFI and yes it is reving at 1600prm when at idle out of gear.

I just wanted to check before I started scaring them! To me in definitely sounded wrong. I'd push it back on the seller to ask when it was serviced etc.

It's going to run like rubbish otherwise and burn a lot of fuel!

I'll have a dig around in the bilge to see if we can empty it and get it clean. The boat was in the water and then lifted and transported on Tuesday last week and then back into the water again and I saw it on Saturday. THinking about we did have quite a bit of rain last week.

Thanks for the answers, I'll tell the new owners the happy news

 

[oGaryo]

so it sounds like it's not the prop.. sounds like an ECM or wiring issue or a sensor error (throttle position sensor?). could always disconnect the remote throttle completely, if it drops to within spec then that's be a pointer, if not, then you can discount it and concentrate on the engine itself.... finally, get a code scanner on it? or as you say, push it back to the vendor and let them figure it out

 

[Sulley]

The crazy thing it's not my boat, as I said I've been "volunteered", I brought my boat earlier this year and spent a lot of time researching and learning things!

From what I can understand the surveyor seemed more on the brokers/sellers side and the surveyor said something about engine issues - the new owners words not mine and they still haven't seen a full surveyors report! When I asked did the have the details about engine issues the answer was no.

I saw them on the boat on Saturday and they didn't even know how to turn the batteries on, plug in shore power or start the engine!!

It's certainly not the way I would have made a boat purchase and I am happy to say my boat puchase/survey/sea trial/broker was a superb experience.

I'll have a rumage around on Saturday and look to disconnect the remote throttle I also think getting a full copy of the survey asap is a priority.

Why me....

 

[oGaryo]

Why me....

coz you're a decent sort by the sounds of it and will go to heaven for your good deeds a friend in need is a friend indeed, 'n' all that malarky

 

[russ]

If you hadn't offered your help Sulley on Saturday then as her pontoon neighbour it may have been me.
If I'm at the marina my very limited knowledge is on offer if needed.

 

[landlockedpirate]

I'm not convinced that the engine is actually running that fast. If it was running at 1600rpm at idle it would make a hell of a bang when you tried to put it in gear, and going between forward and reverse would shred the leg in minutes.

It could be as simple as the rev counter over reading, try removing it and cleaning the contacts, or even just give it a 'tap' and see if it settles down to a more reasonable reading.

Water in the bilge could be anything from leaking bellows (potentially serious) to rainwater leaking through a deck fitting (annoying). If the gimble bearing and bellows havent been serviced in the last 2 years I would get them change 1st.

 

[duncan]

I'm with Mark

You simply wouldn't be able to put it in gear at those revs!

Add that the 'speed at 2200' matches this interpretation.

I definitely wouldn't be touching any throttle linkages because if the revs are 1600 in neutral you have a lot more issues than a throttle linkage because the revs and speed are a complete miss match - as Wiggo put it, you can't have a prop working if it's doing 4.4 knots at 2200! If there is a failure in the prop hub, it will be so bad that you can turn the prop on the drive against the engine by hand - so that's the first test if you really believe you have 1600 revs. If that's sound, but you are still convinced the revs are right, there is a much bigger problem in there somewhere (I can't think of an available prop that would have such a fine pitch so it suggests someone has put the wrong gearbox ratios in the leg ie replaced the leg with the wrong ones) and someone should be taking it up if they had a survey done.

I also agree that the bilge water isn't an issue per se - but should be monitored.

 

[Sulley]

Off to the boat soon I'll be tapping the dials first!! It didn't make a bang when put in gear so there could definitely be a dial issue reding wrongly if did sound a bit fast though.

I'll play around and report back.

thanks for all the advice so far

 

[russ]

I had an engineer on my boat this morning Sulley and asked about your friends boat. You maybe able to adjust the tick over nut as he did on mine this morning. Good luck.

 

[Sulley]

Russ, thanks for doing that!

How's your engine? I know you were not very happy with it last week.

 

[Prospect and Sunray]

Although it might be the dials reading wrong, don'y forget they take their speed sensor off the alternator. Tapping the dials might work, but if not, check the connections on the back of the alternator

 

[russ]

Russ, thanks for doing that!

How's your engine? I know you were not very happy with it last week.

Turns out it was the exhaust flaps rattling which went away after the engine had warmed up. So panic over