Engine destroyed, what next ?

[paddlers]

After two weeks of using my 1993 Mariner 115 engine off Scotlands west coast took my boat to a well known retailer locally for a service and to get an issue with leaking carbs sorted. All went well until they decided to adjust the timing on the engine (unrequested) when they managed to get one of the pistons to damage the bore. They're now saying that the engine is too damaged to repair & that it's nothing to do with them !
The engine was running strongly with no apparent rattles etc.
Has anybody any idea what my next step should be as it seems more than coincidence that on the afternoon that the timing was altered the engine was damaged.

[PeterM]

I'd ;

See if my own boat cover has some kind of legal cover on it ( sometimes an option, sometimes just included ) - speak to them and explain / get advice .

You may have the same kind of 'helpline' through your household insurance or if you have insurance through work - an employee assitance programme - will also have this.

Ask the guys to put in writing the cause of the damage and that they have not touched the timing in any way . Not sure how timing will bugger the bore ?

Ask them for thier liability insurance details as you are looking to make a claim from that .

See what responses you get on the above and post again ...or start talking to a solicitor ...

[Mcd22]

What damage has the piston done to the bore? Were there any underlying faults or niggles with engine while you were running it? Was the timing set correctly before it went in to get the carbs fixed?

I am not sure but I wasn't aware that the timing could cause the piston to damage the bore. I thought that adjusting the timing on an outboard would only affect how well it runs.

[paul tilley]

surely you need to get a mariner dealer to check that the timing is correct or incorrect before coming to any conclusions ,it may be a total coincidence .My sons yamaha hillclimb bike was rebored and had some other work done to the engine at the start of the race season ,when tried in anger it would not pull full revs and seemed very flat ,it turned out to be a bad connection between the plug cap and ht lead ,TOTAL COINCIDENCE no one to blame just one of those things

[Pikey Dave]

It could be a 4 stroke & it's tha valve timing that's been altered rather than the ignition timing, that'd sting a bit.

Forget that! just realised it's a '93 mariner, I'm talking bollix ....again

[ssobol]

It depends if you are talking about ignition timing or valve timing. In the case of ignition timing you could mess it up enough to cause either the piston to fire too early or too late. If it is too early you'll usually only get poor power output. If it is too late you may get detonation instead of burning. This can damage the pistons and the possibly the cylinder walls.

If you are talking about valve timing this usually refers to the timing of the valve operation in relation to the piston position. A lot of compact engines (i.e. the one in your car) are designed so that there is not enough space in the cylinder for the piston to be at the top at the same time as the valves are open. If this timing is off, the piston can hit the valves and damage them. This is usually hardest on the valves and not so much on the cylinder wall. It is possible for the valve to break off and get pounded around in the cylinder. The case of a car engine breaking the timing belt while the engine is running will usually result in an engine that is not economical to repair. If the timing belt breaks on a start you might get away with limited damage.

Due to the size most outboards are timed with gears rather than a belt so it is harder for the timing to change on its own, but it can certainly be changed if someone does take a good part of the engine apart.

[Rokraider]

I would have thought the worse that ignition timing being out will do is to hole a piston, but I would have thought you would have heard it struggling and would have stopped. I suppose if the timing was way out and it got hot enough, it could seize, that could damage the bores. either way, if the timing was way off, I would have thought it would have been a pig to start.

[m chappelow]

I have known 2 strokes where the timing is out for the piston to start pinkin , the piston then starts tumbling about which can do damage to the bore ,or even cause the exhaust portion of the piston crown and edge of the exhaust port to overheat and even burn away though it did rattle loudly.
I

[paddlers]

Frustratingly this engine ran beatifully for two weeks before going in & even the mechanic stated that all the issues (float needles replaced). At @1.30pm rang me to ask if I had the timing cover for the flywheel but I hadn't, he said they'd manage. By 4.30 pm my engine was scrap.
I found some imformation on another post on here describing incorrect ignition timing on these being crucial. They're now denying any responsibility saying they have concerns,old engine, history etc & stating 4 weeks for engineers report etc.
Had some advice from trading standards/C.A.B to write to them initially & then follow up with legal action but I'm curious if others have had any similar problems?

[Chris]

Your going to have difficulty in proving what has happened. I cant see how incorrect timing could have such a sudden impact on the engine. I would be straight round there un-announced to make sure they have not done something daft.

Otherwise you are going to struggle so I would be looking out for a s/h engine.

[m chappelow]

Originally Posted by paddlers

Frustratingly this engine ran beatifully for two weeks before going in & even the mechanic stated that all the issues (float needles replaced). At @1.30pm rang me to ask if I had the timing cover for the flywheel but I hadn't, he said they'd manage. By 4.30 pm my engine was scrap.
I?

Just wondering about the missing timing cover for the flywheel .

[paddlers]

They're available from the USA & I would've bought one had I known it was missing. It has the marks to time the engine on it but the bloke said that they'd rig something and they be fine. Now of course they have concerns about the engines condition but it ran fine for two weeks of waterskiing etc and on the day they rang to enquire about the cover no issues. The next day when it was damaged old engine etc my problem. On one post on ribnet there's mention of setting the spark too advanced causes the petrol to ignite on one side of the piston dam pushing the piston into the exhaust port almost exactly as described to me by the mechanic on the phone but it's how to prove it ?

[TomKat]

There are two approaches:-

1) Collect evidence that incorrect timing adjustment can cause the damage, confront him with it and ask him to fix the damage at his cost. If he does not accept it then go down the legal route - unless you are insured your leagal costs could quickly outweigh the cost fo a replacement engine with no guarantee of success. I dont think either way is sensible.

2) I think I would suggest that you try to work with the guy in the first instance by showing him the post that cites timing adjustment as cause of piston damage and any other more reputable sources - maybe a authorised Mariner dealer? I don't think you will ever be fully compensated for the damage but if you work with him you might be able to mitigate some of the costs - if for example he accepts any blame he may not charge for any corrective labour required and maybe help in sourcing a secondhand powerhead, rebore etc. This assumes you would trust him near another engine.

Just my tuppence worth...

[Milgrip]

Originally Posted by TomKat

There are two approaches:-

1) Collect evidence that incorrect timing adjustment can cause the damage, confront him with it and ask him to fix the damage at his cost. If he does not accept it then go down the legal route - unless you are insured your leagal costs could quickly outweigh the cost fo a replacement engine with no guarantee of success. I dont think either way is sensible.

2) I think I would suggest that you try to work with the guy in the first instance by showing him the post that cites timing adjustment as cause of piston damage and any other more reputable sources - maybe a authorised Mariner dealer? I don't think you will ever be fully compensated for the damage but if you work with him you might be able to mitigate some of the costs - if for example he accepts any blame he may not charge for any corrective labour required and maybe help in sourcing a secondhand powerhead, rebore etc. This assumes you would trust him near another engine.

Just my tuppence worth...

I agree with TomKat, I believe this would be your best approach.

[beamishken]

id try and work with the guy its a 20 year old engine proving what went wrong is going to de difficult

true incorrect timing can damage pistons but incorrect fuel
mixture can do exactly the same thing (melt pistons) and it went in for a fuel fault!

I ran a garage for 25 years and occasionaly things go wrong if the guy is an honest trader then he will feel guilty about the engine going wrong while in his custody but its human nature to look after yourself and deny liability give him the chance to quote for repairs & hopefully he will try and rectify the situation by offering to complete the repairs as a reduced rate

if you get a favourable response then go with it if hes negative and asks the earth for repairs then get it back & start looking for a sh engine

in my opinion its not worth the stress and expense of involving solicitors
but thats only my opinion of course

whatever happens good luck

[paddlers]

I agree that it's very difficult to prove & my initial feeling from the first phone call after the phone call to say there was a problem when I asked " is it anything to do with altering the timing " was " it's nothing we've done!".
The fuel was occassionally leaking from carb 3 for the whole of our two weeks holiday & never caused a running issue at all. New tank & fuel line plus I mixed all the fuel myself( Yamalube) at 50:1 fresh fuel in August. Used @ 140 litres with no problems, no unusual noises/smoking etc & pulled like a train!
Of course the firm are not admitting anything but having taken advice from C.A.B & trading standards that's to be expected !! It costs £70 online to put it into court and you'd think commonsense would dictate some flexibility on their part but I suppose money rules!
I was hoping that someone could put me onto somewhere that proves the link between spark advance & piston damage that would support the fact that it's possible to damage the engine?

[Pikey Dave]

Originally Posted by paddlers

I agree that it's very difficult to prove & my initial feeling from the first phone call after the phone call to say there was a problem when I asked " is it anything to do with altering the timing " was " it's nothing we've done!".
The fuel was occassionally leaking from carb 3 for the whole of our two weeks holiday & never caused a running issue at all. New tank & fuel line plus I mixed all the fuel myself( Yamalube) at 50:1 fresh fuel in August. Used @ 140 litres with no problems, no unusual noises/smoking etc & pulled like a train!
Of course the firm are not admitting anything but having taken advice from C.A.B & trading standards that's to be expected !! It costs £70 online to put it into court and you'd think commonsense would dictate some flexibility on their part but I suppose money rules!
I was hoping that someone could put me onto somewhere that proves the link between spark advance & piston damage that would support the fact that it's possible to damage the engine?

I know it's not what you want to hear, but IMHO you're on a hiding to nowhere by going to court. The dealer will say that you took the engine in for a service & to attend to a fault on the carb, during the course of the service they found damage to a cylinder & reported this to you.
The engine might have been running with a dodgy cylinder for a while.
You could ask them to put the engine back together again & see if it runs.
You could ask for the engine back & get a second opinion on it's condition.
You could have the dodgy cylinder re-lined (if this is possible on this particular engine , I dunno) & a new piston fitted.
You could bite the bullet & get a replacement engine, which in all honesty will probably cost as much as all the above if you replace it with one of similar vintage.
You could jump up & down, stamp your feet & see if you get lucky with the dealer, but start off nicely

[9D280]

Tech bit in plain english:

It's a 2- stroke. There are no valves, as the piston doubles as the valve. To ensure the incoming "blast" of air / fuel mix both fills the void & "blows" the exahust out the exhaust port, the piston has a "dam" across the top:

http://www.sterndrive.info/sitebuild...rd-pistons.jpg (random example from Google)

if the timing is advanced too much, the spark happens before the full "flush" has happened, resulting in more air / fuel one side of the dam than the other (the other side is still essentially non combustible exhaust).

Because the piston is it's own valve, if the spark happens too soon, at the "bang" moment the piston is still below the inlet / outlet ports, and so when the spark goes, the mix ignites onthe inlet side of the dam and creates a bigger "bang" on the inlet side than the outlet - net result the piston is pushed hard into the exhaust side of the cylinder, while still rising to compress the mix.

This results in a collision between the top corner of the piston and the spark plug edge of the exhaust port. The resulting debris gets wedged in the rings & makes a nasty mess.

Not that I know from experience or anything......


So, Replacement piston (Mallory / Sierra) - £75-100 or shedloads for an OEM one.
Replacement rings (for the other cyls) about £10- 15 for a set (maybe a little more if it's a V (more cyls than my Clamshell)
Rebore - I was quoted £120 for three cyls. Probably a little less if yours has a "proper" cyl head - mine is a blind bore design, which did complicate matters slightly.

The biggest PITA s dismantling it for the rebore. On the plus side, you don't need to do all the bores.



FWIW when mine destroyed itself (Locknut on the spark advance let go, so the adjuster screw wound itself out and the first I knew of it was when I opened the throttle and it stopped dead as the plugs were shorted by the metal that was chipped off the corner of the cyls!) I priced up a full rebuild. As Pikey says, it came to aboiut the same as a replacement engine (of unknown history). I decided to rebuild so I at least knew it was done properly. During the rebuild I fitted al lthe latest level parts, so dragging my engine form a 1970s build to a last production, which on paper at least should prevent it form suffering form all the Clamshell problems they were reknown for in the early days.

[paddlers]

Thanks for that, just the sort of detailed post I was looking for. The point of my origional post is to understand how adjustment of the timing which by their own admission they did could result in the destruction of a bore which they stated " a piston clipped one of the ports"!
This engine ran well right up to this particular afternoon. It's also a blind bore but the prices you've mentioned don't seem unreasonable when you consider the cost of an equivalent outboard. The problem really is the dealer who comlpetely refuses to admit they've possibly made an error & rectify the problem! It's a bit of a worry given the prices charged & the instant that there's an issue "sorry mate"!
I intend to write to them next giving them an opportunity to reply & repair the damage but given that I've spoken to them on the phone I'm not optimistic.

[DJS]

It is unlikely that the timing would cause this unless you were running under load for a long period. The main cause of bore damage is very often due to overheating, in these cases and if you could get a look at the pistons you would find the rings compressed into the ring groves with the piston material often dragged over the rings. The question I would ask is - was an water supply or tank used during the testing or running of the engine?