mercruiser 3.0 lx belt help?

Moonshiners

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www.speedandstrip.co.uk
Went our for a cruise yesterday in our "new" (1996) sealine 210 WITH 3.0 lx MERCRUISER and outdrive. Half way to pompy our alternator drive belt gave out, the motor kept running and got us home.

Before I realised the belt had gone the first thing i noticed what that steering to the right was much more difficult (left was okay) and the volt meter was reading about 10/11V (it normally charges around 13v+

- So I figure one of teh belts has gone or a alt or pump bearing has gone - bearings seem to spin fine though.

Don't know my way round these motors just yet so...

The belt that let go was the altenator belt and what ever else this was connected to (it got shredded). The Steering pump belt is still intact.

1) Does the Altenator belt drive from the crank and then run ALL other pulleys?

2) The engine kept running and got us home. after switching off the ignition there was a serious of cylinder fires (engine trying to keep running) before cutting out. - Now the engine turns over but wont start.

Is this because of there is no belt to drive the fuel pump or something or by having run it home with no belt have a seriously nackered something?

3) The crank pulley doesn't look like it lines up with the others, but also looks brand new - like it's never had a belt(normal) wear from belts. Seems strange if everything is driven from the crank pulley????

Can't think that anything likely seized as it ran fine up to the mooring, the only concern is the missfire after ignition was off and now not starting... any suggestions or info on the belt system or even clear pics would be great.

Cheers,
 
[ QUOTE ]
The belt does the alternator and the water pump seems that it has overheated so be prepared for the worst

[/ QUOTE ]

Surely if it had overheated and seized it wouldn't have run fine back to the mooring, temp gauge stayed normal...

Not saying your wrong, but an outside chance it should all go wrong the same second i switch off the ignition about 40 mins after it going...?
 
if alpha one then pump is in the sterndrive

merc30.jpg



belts look like one for alterbnator & one for power steering
 
Try taking out the battery and giving it a boost on a car charger.
Replace the broken belt, and try again.

Seawater pickup is from the impellor in the leg, but I believe that upper pulley has a circulation pump behind it too. It's possible you have cooked the cylinder head a bit.

dv.
 
Thanks guys, well at least it should have got some cooling, I have to say I didn't notice the temp guage going nuts.

The post ignition after I switched it off does indicate to some additional heat in the cylinders, I guess we just have to replace belts and cross fingers.

I'm presuming becuase the altenator belt let out, that would explain the steering going hard to the right (valve open to the left)???

Fingers crossed it didn't get too hot!

Will boost the batteries and change out the plugs before firing her up, she's on a swing mooring, so all a bit of an arse really!
 
Yes the Alt belt runs the block circulation pump. The seawater pickup is generated by the impeller in the lower drive gearcasing. This supplies the cooling water to the block when the thermostat is open and to the manifold, so even if the belt went, you would have some cooling water through the block. Not enough for a heavy engine load though.

At 10v on your voltmeter, I suspect this is where the misfire came from.

For peace of mind, have the compressions checked, you should have around 180 - 190psi at cranking speed, WOT, with a max differential of around 10%. If the lowest reading is towards the rear of the block, you cooked her.

Can't rely on the temp gauge reading too much as the sender is in the thermostat housing, which has a cool water supply irrespective of the circulation pump output.

And for your next question: To fit the new belt, you remove a spacer between the engine mount and the engine block, held by 2 through bolts on the right hand side of the engine mount as viewed from the front. Kind of just to the left of and beneath the Alternator.
 
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