Just bought a Whittley Cruisemaster 700 - Have a few questions

[juggernaut]

Does anyone else think low fuel pressure could be causing such a sluggish motor? (if indeed it is the motor)

Not directly on point but from my experience with following cars at track days - low or no fuel pressure can cause the ECU to put the motor in limp mode until fuel pressure is restored. This can happen with a low fuel tank level and g forces caused from cornering starve the fuel pickup with the result the ECU puts the motor in limp mode. Unfortunately, the shut down happens abruptly mid corner and doesn't give much opportunity for the following car to miss the "limp mode car" from being rear ended. My brother had a pre-Chev HSV that would do this. Obviously these cars would benefit from a surge tank.

Similarly, in your case it may be that the ECU has detected low fuel pressure and is limiting engine acceleration and possibly rpm. Could even be a lazy fuel pump - either old and/or not getting sufficient voltage.

I'd also go back to that list of checks I previously posted. In particular, I wonder if the injectors are not flowing correctly - particularly the one on the lazy cylinder.

Personally, I'd probably not run the boat until someone in the know could take a look at it with some diagnostic equipment.

[bonneville]

Hi Dave,
listen, I re looked at your psi at idle and Im positive you need at least 30 psi there ! remember this will continue thru its performance probably up to the 3000 rpm range, which could explain your lack of power at hole shot, you would be running quite lean.
Yep, alan is a great young bloke, always there for a bit of advice and has a good rap !
the way I look at it, while I understand your frustration ( a bit like me fibreglassing for the first time) but you will eventually get to the problem, you've already eliminated a few issues and its a great way to familiarise yourself with the engine.
I"d be checking out the fuel filters,pump, take it for another run on the water, also maybe consider taking a small tote tank, check whether on standard fuel lines its improved, if not, run the tote tank and see if fuel pressure is better !
stick with it mate, its just a process of elimination !

that's a good point from jug, a bad injector will cause grief

P.S if you need a hand on a water test, more than happy if you have no one else to come for a run with you !


B

[newbienewb]

thanks guys.....

so how does this sounds....

1) New fuel filter / water separator
2) injector clean / test
2) test fuel pump via external container.....still need to figure out fuel flow here. Also need to figure out where the regulator is.

Thanks for the offer of company bonneville. Where abouts are you located? I usually launch at either patterson lakes, or martha cove.

Cheers guys. Think its time for me to hop into bed......

untill tomorrow!!

dave

[Gon Fishun]

Do they have ignition timing? Just curious.

[juggernaut]

Long shot but check out this thread and post #14.

http://forums.iboats.com/forum/engin...ou-to-solve-it

Does it have a fuel cooler - if so i think the reg is on top of the cooler.

[bonneville]

Dave, Im in the eastern suburbs as well, about 30 minutes to Patterson lakes............


cheers
B

[fisho8]

Wow what a read seems like a friggen marathon to be just rip the engine out throw it away and put a diesel in it. I love the 700's they are a fantastic boat. I drove one of these with a diesel in it testing it with a boat salesman mate of mine at Northside Marine and it went fantastic...They are expensive but the long term benefits will pay for themselves. Bloody Mercrusiers....Rubbish. Sounds like it has had a very poor service history.

[newbienewb]

Thanks guys...

Wouldn't a bad injector be noticeable with the engine running?. I guess not totally when I think about it.

I just cant seem to get my head around the fact that this was a sudden thing. When I say sudden I don't mean mid cruising, but it certainly didn't degrade over time, whatever happened seemed to happen quickly.

I would have thought an injector would get blocked over time?.

I do agree that the fuel (even though only a small amount) from the previous owner had been sitting in there for a while, but when I removed the filter it certainly didn't show any signs of water or significant debris.

Gon Fishun - its a good point, it did have a look for timing marks etc, and did a bit of reading on how to set correct timing on these things, but I didn't get anywhere. I would like to check the timing, and have a timing light - but cant even find any timing marks on the timing case / pulley.

fisho8 - I think you are right - poor service history is a factor here. I knew this when buying the boat, but unfortunately these issues with the motor didn't show up when sea testing.
I think I can make it work, and in all honesty I think the mercruiser motors are actually not too bad. Chev has a good track record.

Bonneville - I may need to get you around to help drown my sorrows!

Dave

[mal555]

Dave, definitely check the prop size in relation to poor hole-shot, the previous owner/s may have been oblivious to the problem, could even go right back to mis-information when the boat was new. Over-propping is bad news all round for any engine, like driving around town in your car in top gear.

We have always found the fitting of the "Original" Stingray hydrofoil improves hole-shot and planing attitude on this particular boat, as they are sensitive to trim. The cheapest thing you can do for noticeable improvement, something like $120.00.

The Cruisemaster is a great boat for the often choppy bay, definitely use the trim-tabs though to bring the bow down into the chop, makes the ride a whole lot better. They are a tough boat (regardless of what some folks think because of the luxury level) and can handle adverse conditions very well.
Remember to raise the trim-tabs fully and trim out the Sterndrive (slightly) when running with the (big) sea behind you, because like all boats, if trimmed in, they will "bow steer" or feel like broaching.

good luck and enjoy your boat!

[Bull]

Wow what a read seems like a friggen marathon to be just rip the engine out throw it away and put a diesel in it. I love the 700's they are a fantastic boat. I drove one of these with a diesel in it testing it with a boat salesman mate of mine at Northside Marine and it went fantastic...They are expensive but the long term benefits will pay for themselves. Bloody Mercrusiers....Rubbish. Sounds like it has had a very poor service history.

Big call saying Mercruisers are rubbish!! I've had a pretty good run with mine so far.

[The Silver Unicorn]

Seems to be what happens on here these days, if you dont know anything about something you just bag it out.

I

[JulianDeMarchi]

All we need is a yammie inboard... that'd end all debates!

[The Silver Unicorn]

Id take an etec over a yammy any day of the week.....

[chocolatemoose]

i think mercury sell enough engines with its mercruisers to make it kinda mute

[scottar]

You don't want a mute one - none of em seem to go any good when the noise goes away.