Engine stalls

[wayneakp]

Hi all

I now have a problem with the port engine (Volvo penta AQ145) on my boat. It runs fine at both idle and cruising. However if I make a tight turn at low revs the engine stalls, much in the same way as pulling off in a car without enough throttle.

I have noticed that when the throttle is engaged I instantly loose 300 revs.

Any ideas please?

thanks

Wayne

[senator]

what rpm is your idle set at. On volvo V60's it is supposed to be 750 not sure about the 4 cylinder versions. And the other thing is not to rely on Volvo clocks. Take it with an oscilithingy at the fly wheel.

when you say it loses 300 rpm when the throttle is engadged I assume you mean you have just nudged it into gear from netrual. if this is the case then something in the drive train is causing drag so I would start your investigation with the leg.

have you had them serviced recently or attended to the greese points at least?

Ian

[wayneakp]

Hi Ian

Thanks for the reply.

The rpm was set to about 800 - i increased it to 1000.

The boat has just returned from the dealer where they were looking at it under warranty. Apparently it was all o.k - the dealer also said they would check everything out under a pre-delivery inspection - I am begining to doubt this as several other things have not been attended to and I am starting to get a bit fed up with them.

Anyway - both engines seem to do the same as far as loosing revs when the throttle is just nudged froward. Presumably as the props take up some resistance from the water the engine speed will drop so perhaps I need to make sure that as the throttles are moved forward the carbs also begin to open up.

I will have a look at drive train the best I can with the boat in the water.

I have a guy coming up from Woodbridge in the morning to do some training. I just hope the engines behave so I dont waste my money.

thanks

Wayne

[senator]

hi wayne, would definately cancel the training if you still can. There is no point in practicing close quarter stuff if the engines are cutting and that will be IMHO your biggest gain from inland training, others may argue rivercraft and crew organisation is just as important.

You should be able to manouvre your boat on tickover and there should be a fair bit of play from where you engage gear to where the throttle starts to open.

If it is under waranty I would personaly send it back. there are lots of things in the drive train that could cause drag but I can't think of a cheap one.

[senator]

just thought of one but will leave Adam to fill you in on it.

Ian

[senator]

another thought.

Is it the engine with the power steering on that is stalling? If it is it could be to do with the power steering pump

[wayneakp]

Hi again Ian

I am not entirley sure but I dont think there is any power steering - I will have a look in the morning.

I am able to drive around the marina at tickover. I find it (the port engine) stalls on tickover when I have the wheel hard over against tide or wind. thinking as I type I will also check that the mechanism is not fouling any wires or pipes.

I have already warned the training guy about the problem and he is still coming. I think it may also be useful to have the independant view.

Thanks again for your help

Wayne

[senator]

if you do have power steering it will be normaly be off 1 engine and when you are on full lock it will do the same as your car and put load on the engine.

You will know if you have power steering if you start one engine, if the steering gets lighter you have it, if not turn it off and start the other engine and try the steering again.

It could be that you are holding the wheel hard over and stalling the engine with the extra load of the pump.

Ian

[C.Ricko]

Did you say in a previous post you had trouble restarting?

that makes things a bit more interesting, I initially thought it was a diesel filter thing but you have petrols! I dont know about petrols apart from perhaps a blocked or wet air filter??

If there is no problem restarting could it be something as simple as a rope on the prop?

[Jim]

You're right there Clive, rope could cause it at low revs.

Wayne, here's another thought for you, have you got a fuel filter on both engines? I know I've got a Beemer petrol but for years at low revs I had a similar problem until my mate Gary (of Boatshed Norfolk fame) helped me to service the engine in 2006 and emptied the water trap filter. You would not believe how much he got out of there and ever since, no probs until recently....which means it wants another empty!!

BTW this isn't the filter you would change on a service. It is fitted in the fuel line before the disposable units and may be difficult to spot

[Happy Jax 3]

Hi Wayne

Very strange indeed, does it stall out on both locks port & starboard?

I had a Princess with twin AQ140 petrols which are basically the same engine. From memory the engine wiring harness runs along the port side of the engines and out to a multi-plug at the rear. Check your steering gear is not fowling the harness on locks, could either just be moving it slightly resulting in a poor connection or a direct short if it has rubbed through the harness. There is a fuse block in the harness behind the distributor, the connections are prone to corrosion, maybe worth checking.

When it stops does the engine cut instantly as if the ignition is switched off,or does it slowly stall?

If it is still has points & condenser you could try changing the condenser as they can break down under load, although you would expect problems during normal cruising.

As previously been suggested it is worth checking for rope or such like behind the prop, these petrols do tend to stall with the slightest drag when at idle.

The only other thing I can think of over and above what has already been suggested is the U/J in the drive seizing when on lock or the drives are going past the steering lock stops resulting in the u/j's going beyond it's operating angle, although you would expect a bit of clonking.

As you say though, you have a warranty, let them sort it.

[wayneakp]

Hi all

Many thanks for the replies.

No power steering so not that..I have checked the cable runs etc and all seem o.k.

We got through our training today by increasing the idle speed but still had a few stalls.

The really interesting thing is when we were piddling around the marina basin all was o.k but as soon as we hit the river the engine revs dropped by 300 rpm when the tide hit the boat.

My instuctor also mentioned rope / fishing line so I will see if the drive will tilt far enough to see anything.

However the engines have never been quite right so I will advise the dealer. To be fair they have at least tried to sort the problems with no quibble up to now.

Anyway - what a lovely day it was out there today - and had it all pretty much to ourselves.

regards

Wayne

[Mowjo]

Wayne! Insist that someone from the Dealers comes out on the boat with you, at least when it does happen they will see for themselves, they probably test the boat when it's static, but as you say it only happens under load they wouldn't see it has a problem,,