Engine overhaul - Worth it?

[Ianfs]

Do you know how many pairs of shoes £1000 can buy you!!!! At least two!

You would get on extremely well with my wife.

1. Work out what REALLY needed to be done, then worry about the cost of doing what needed to be done to the engine.
2. Work out the worse case scenario of MIGHT need to be done, and attempt to come to terms with the costs involved.

I think the first thing to do, is to get this out of your mind totally.

It proves that I really LOVE the boat and all that she has to offer, and that I am a total nutter with my head in an almighty bucket of sand... but then we're all boat owners, so I'm sure that doesn't come as any surprise!

Next, love the boat for the moments you have on her, but do not love the boat totally and unconditionally under any circumstances. In boaty terms this "will" cost you a fortune and cause "old man/woman syndrome" causing you to keep her even when she is sitting doing nothing and you do not want to sell her.

Starter and alternator. As mentioned, they're still the originals. Although not the biggest issue if they do break, but it will mean a call to sea start if we are out, and likely a couple of precious boating weekends lost by the time we've sourced another and gotten around to fitting it. Plus, I assume if the starter does go, it'll be when you're just about to leave some far flung marina, meaning you have to pay for a tow back to your home port or pay to store the boat in the marina while you sort things out - either way incurring more expense.

The starter maybe, about £110 without labour to replace, but have you noticed any issues lately?

Alternators can last the life of the boat, not much to go wrong here and as we know they only charge the starter battery and/or accessory batteries, worst case, you have a flat battery somewhere. Usually indicated by a battery warning light on the dash.

Carb rebuild - We had this done three years ago, but this season, when you accelerate hard from a slow speed, the engine bogs down. Accelerating gradually is fine. Is this something to do with the accelerator pump or something like that, and would a carb rebuild sort this? Also, in real terms how hard is this to do?

Before you had the rebuild, did she bog down, did the rebuild stop it or is it only this season?


I think a compression tester is a good idea and will tell you a great deal. A reminder about compression testing though, don't think that the original compression is what you are looking for, however you should be looking for big deviations between the cylinders.

I'm not sure about the oil pump or petrol lift pump. Certainly the petrol pump usually cannot be serviced so the whole thing requires a new one, but these tend not to break easily.

[annageek]

Carb rebuild - We had this done three years ago, but this season, when you accelerate hard from a slow speed, the engine bogs down. Accelerating gradually is fine. Is this something to do with the accelerator pump or something like that, and would a carb rebuild sort this? Also, in real terms how hard is this to do?


Before you had the rebuild, did she bog down, did the rebuild stop it or is it only this season?

Annoyingly, we hadn't had the boat that long and she was running a bit rough so we just had someone rebuild it to get us on the water without battling with a dodgy carb... so I really can't remember what it was like before hand. I think it was batter after the rebuild, but the problem crept back in the season before this one just gone. Looking at the invoice for the Winterise we paid someone, there's no sign of any fuel stabilliser being used (the company we used - who I will not recommend - charged literally for everything else, so they wouldn't have missed the opporuntity to charge us for £5 of fuel stabiliser!) so it likely laid all winter with stale petrol in the carb. Would this be enough to start varnishing it up to affect performance?

[_Ed_]

Some very kind words said here! thanks

Ok back onto the question, Anna, any mechanical part can be assessed and inspected with time and a little knowledge to ensure suitability and reliability. Things like starter motors are easy to strip and inspect, they typically have bearings made from brass or steel ball bearings, and again can easily be inspected with a few basic tools. If you wish to learn, then they are also great things to have a play with. You absolutely do not need to replace things just because you feel they 'might' go wrong.

Carbs are always temperamental and can be user serviced, but ensure you have all data available to hand before you embark on such a challenge. If they are worn (unlikely at 400hours) then usually best to replace, or you may be forever chasing your tail.

FWIW, I don't believe in fuel stabiliser. But it is advisable to drain float bowls, rather than letting the fuel evaporate away from within. P.s. Most old outboards are never serviced. I've still yet to see any thing from from fuel itself its usually from other things that react with it. Old lines perhaps breaking down, or wrong sealant used etc.

[betty boop]

FWIW, I don't believe in fuel stabiliser. But it is advisable to drain float bowls, rather than letting the fuel evaporate away from within. P.s. Most old outboards are never serviced. I've still yet to see any thing from from fuel itself its usually from other things that react with it. Old lines perhaps breaking down, or wrong sealant used etc.

tend to agree on that too, last 2 or 3 years I haven't used stabiliser in winter time and noticed no difference/ill effects but I have left left the tank empty 1/4 full rather than full as that seems to be the new mercrusier recommendation due to the increased veggie content of todays fuel. Not sure if thats a good idea or not though. The carb is sprayed with fogging oil but that doesn't seem to stop the green fuel slime in some of the pipes. 10 years in and still on the original carb - fingers are crossed but Im still biased that the current engine starting when hot isn't carb flow related, more so Merc patented electric chock related.

[Ianfs]

who I will not recommend - charged literally for everything else, so they wouldn't have missed the opporuntity to charge us for £5 of fuel stabiliser!) so it likely laid all winter with stale petrol in the carb. Would this be enough to start varnishing it up to affect performance?

As Ed knows, I left some stale fuel in my tank once. I forgot to drain it after overhauling the engine and I use the term overhauling quite lightly as I didn't touch anything mechanical inside the engine.

The fuel was about 2yrs old, the engine started ok after a few pumps on the throttle, except that under load at speed it backfired, the fuel was acting as if the mixture was weak.

I'm no expert but as far as I know fuel stabiliser really only stops fuel from absorbing moisture.

What I do know about petrol (qualified by e-mailing fuel refiners, asking them about petrol shelf life, like BP, Exxonmobile etc back in 2006) is that fuel companies add different additives in the Summer months compared to Winter months, these are called light ends and are usually butane or propane. Also there is a percentage, 10 I think of Ethanol in petrol. As I said I'm no expert but if the Light Ends evaporate and some of the other stuff evaporates this would have caused my engine to backfire, I'm sure. Also when I analysed the colour of the fuel, fresh fuel is much lighter and clearer. As far as I'm aware the varnishing you mentioned is not as predominant as it used to be, because of additives used and better refinement processes.

I would say that if you are concerned about your carb and stale fuel, see if you are able to drain the fuel off or mix it with some Shell V power or similar and then buy a carburettor kit, they are cheap at around £20-£30 and strip it. It's probably a 2bbl Mercarb, I've got some pictures somewhere when Ed stripped mine down and its pretty simple. A word of advice though if you do strip your carb and see that the Aluminium inside it is a bit yellow, this could well be Alodine and not varnish so don't be tempted to clean it off, its there as anodising to protect the Ali from corrosion.

[_Ed_]

A word of advice though if you do strip your carb and see that the Aluminium inside it is a bit yellow, this could well be Alodine and not varnish so don't be tempted to clean it off, its there as anodising to protect the Ali from corrosion.

Very good advice, some people sand blast things thinking the yellowing is some kind of dirt film then wonder why things rot away!!

[Ianfs]

Any decisions on what to do next Anna?