Even more Alpha 1 aggro

jhr

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jamesrichardsonconsultants.co.uk
Some of you may remember that I was having an up-and-downer with my Boatyard about the apparent lack of oil in my boat's outdrive leg, following an impellor change and leg service over the winter.

Having managed to get this resolved, I went down at the weekend to go out for the first time this season. Everything worked, but on starting up, I initially thought that the engine was misfiring, as it sounded very rough and loud. I went down the river and back again (including a naughty full bore blast along the lower reach when no-one was looking /forums/images/graemlins/blush.gif) without anything going wrong, but didn't have the nerve to go out into the Solent.

On further investigation, it sounds and looks as if there is exhaust gas exiting the leg at the top, as well as through the prop. and it's definitely much louder than it was. Having given the matter some thought, I am veering towards the theory that, somewhere along the line, the Yard made an error in connecting up the exhaust gaiters when they put everything back together - or that the gaiters have perished (though I did ask the Yard to check and replace them if necessary, when they did the service). There is no visible ingress of water, thank God, but the din is giving me a headache and the whole thing is feeding my rampant paranoia about all things mechanical.

Anybody agree/disagree with my diagnosis? Any other ideas? Engine is a Merc 5.0 efi, linked to Gen. 2 Alpha 1.

It would be nice to get out some time this season. /forums/images/graemlins/frown.gif
 

capnjack

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An impeller change and service would not normally incorporate touching the bellows unless specified. However, if the yard changed the upper seals then yes the bellows wouldh've come off to do the job.

I asked the technician who did mine recently, what would happen if they came loose, he said it would sound like a dragster.

V8's normally have an exhaust tube and not bellows unless yours is an early model, in which case it could be suffering from the ballooning caused by the back pressure and then may have chafed the UJ bellows and holed, in which case the UJ bellows may need replacing too.

Your problem does sound like the tube/bellows have come off.
 

mercman

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Exhaust tubes are fitted regarding the horsepower of the engine. Normally 350 Mag and above. 3.0, 4.3, 5.0 and 5.7 and most 350 mag depending on installation spec all have bellows. A service incorperates checking the bellows and on a drive service you have to check the continuity wire circuit which involves lifting the bell housing so if the bellows were off it should of been noticed. Another reason for the excess noise could be you exhaust flaps. These sit in the exhaust tube and if are missing, broken or failed a different exhaust note could be heard.

Sorry im lost when you say if they changed the upper seals then the bellows would of come off??? What do you mean??

Jhr if you want some advice pm me.
 

jhr

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Post script

The conclusion to this little saga. The problem has been fixed - I hope. One of the jubilee clips on the exhaust bellows hadn't been tightened up after the service; terribly sorry, Sir, etc. etc.

Ho hum....................
 

jhr

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Re: Post script

Yes, agreed and my wallet is duly grateful!.

Just getting a bit hacked off 'cos the boat's been back in the water since early April and the sum total of our outings so far has been one trip up and down the river.

Anyway, all sorted now. Wind and rain forecast for the weekend, I see....
 
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