Engine Damage - is it serious?

Mark · 29 June 2004, 21:20

Fellow RIBers,
I'm into to my 4th week of RIBing and following my visit to Poole harbour on Sunday I decide tonight to flush the engine on my drive. While on my hands and knee's fitting the flushing ears I noticed a crack in the casing around my propeller. The crack looks quite old and even though the engine grounded just after launching from Rockley point on Sunday, I was only travelling at walking pace, so I'm convinced the crack was there before.
I want to know if the engine is still safe to use?
The crack is not in a load bearing area and as far as I can see is not going to cause a problem.
I have attached a picture of the crack so please take a look and tell me what you think.
I will eventually get it repaired, but would prefer to do this over winter.

Mark

Hightower · 29 June 2004, 21:36

Providing you aren't losing oil or taking water into the box I would guess you'd be pretty safe to use it, but I would get it looked at by your local service centre and from my experience you'll probably get some, very helpful, free advice. As for a repair....be careful, because welding cast alloy is difficult to do properly and because of the close proximity of the bearing housings, the alloy may distort. But that said, there are Engineering companies around that can weld under water to stop the heat distrubution. It will mean stripping the box though!!

Good luck,

Andy

tue · 29 June 2004, 22:05

YES.

Get it looked at ASAP. Although the crack may be old that just means its had more time for salt to build up in it and make it larger eventually pushing its way into the "gubbins" area of your gearbox with messy results.

Andy · 29 June 2004, 22:32

Its likely that a salt buildup inside the case between it and the exhaust manifold has caused the problem. Everytime the salt gets wet it expands causing internal pressure and hence cracking. Its a common problem. You need to stop using it as if the crack continues it will arc back towards the prop and a bit of metal will drop out. This can be bolted from the inside to stop you loosing the metal bit, but you do stand a chance of loosing it and the gearbox internals when they eventually falling out under power. This can be fixed completely by welding. The welding will be lots easier if you do it now before it gets any worse. My advice to you is to take it to an outboard engineer immediately.

How do I know this ..... it happend to me last year on my Yam 115 and the thing runs great after the weld ... no probs at all. It cost me £300.

Matt · 29 June 2004, 23:27

Propeller Revolutions in poole would be good people to talk to.

jwalker · 30 June 2004, 00:37

It's difficult to tell from the outside whether it has reached the bearing carrier. Take the prop off and look inside, if it hasn't, drill a small hole at both ends if the crack, this will stress relieve it and prevent it propagating. 2mm dia holes would be ok.

Mark · 30 June 2004, 08:10

Thanks to everyone who replied to my post. I will remove the propeller this weekend and try to work out the extent of the problem. I plan to get it welded up or find a 2nd hand replacement.

Mark

Andy · 30 June 2004, 08:39

your local outboard centre will probably know a good welder, they will have seen this before. they also need to do the work to prep the leg for the weld and put it back together after.