Size of nuts...

[Reptile Smile]

Hello all,

 

After a sudden and catastrophic stop of my engine last summer, I haven't touched it since. I was on my way back from Bristol, and it just stopped - it didn't go bang, there was no smoke - nothing like that. It just stopped and wouldn't start again.

 

I was convinced it was a seized engine (a BMC 2.2, BTW) but my neighbour became convinced it was the starter that had jammed/not cleared properly. I was always sceptical about this, but on taking the starter motor off, it was indeed (the starter) jammed, and on taking it off, the boat would now go into gear, which it wouldn't before.

 

It then remained to see whether the engine would 'manually' turn over, or whether it was still seized, and the starter was knackered in addition.

 

And herein is the problem. Due to where the engine is mounted, I can't get to the nut on the end of the flywheel to try and turn it over. Well, I can get a socket on to it, but I can't see it or anything. The nut is massive - I tried both a 1.25" and a 32mm today, and they were too small, so I guess it must be at least 1.5"? Does anyone know the exact size, so that I can go buy the damned socket, turn the damned thing over, and answer this once and for all?

 

For what it's worth, I shoved a heavy-duty screw driver into where the starter motor came off, and could turn the engine, albeit by dint of a lot of effort. Is this a good sign? Should it take a lot of effort? I didn't pursue this too far, as I didn't think it would be doing the starter gear that much good - but it definitely turned...

 

Cheers all

 

Ian

[RLWP]

<snip>

 

For what it's worth, I shoved a heavy-duty screw driver into where the starter motor came off, and could turn the engine, albeit by dint of a lot of effort. Is this a good sign? Should it take a lot of effort? I didn't pursue this too far, as I didn't think it would be doing the starter gear that much good - but it definitely turned...

 

Cheers all

 

Ian

 

Yes, it takes a lot of effort

 

It's unlikely that you will have a seized starter AND a seized engine at the same time. Why not get the starer fixed and see what happens

 

Richard

[springy]

IIRC i measured one about 6months ago as 42.5 mm - the nearest sizes are 1"W = 1-1/8" BS which is 42.42 mm

or 1 -11/16" AF which is 42.86mm - I managed to borrow a 1-11/16" AF socket which did the job, however as richard

sugested turning the flywheel with a lever in the ring gear is hard work but if you can turn it then it isnt seized solid so

I would go along with the idea of sorting the starter and see where you go from there

 

springy

[WotEver]

I would go along with the idea of sorting the starter and see where you go from there

Thirded

 

Tony

[larkshall]

You will need the 1" 11/16 AF socket on most bmc's, or a very large whitworth ( I think 3" fits).

 

If you are careful and have enough room a pair of 36" stilsons would work if used with care.

 

I'll bet motor isn't seized, but it will be a bugger to turn for first revolution, as its been left standing for best part of 9 months

[BEngo]

Thirded

 

Tony

 

 

Nah. The engine was running- it stopped. Something was/is not right with the engine. It does not appear to be mechanically deranged, from the original description. It may have run out of fuel (empty tank or blocked main filter or that little filter in the DPA pump or failed feed pump or....). It may have been too hot and siezed (in which case it might go round OK now it has cooled but the cooling arrangements need to be looked at). It may have run out of oil and siezed though that would not be consistent with the OP's description of the stopping as uneventful. It might even have a rag or something stopping the air inlet. Whatever it is needs looking into before re-starting lest more damage be done. The starter motor is a side show.

 

I would suggest loosening all the injectors in the head and then it should turn over readily, with mucho hissing from round the injectors, by pulling on the alternator belt. If not, it may have siezed and some serious investigation is needed. If it does turn over OK, fix the starter and fit the injectors to the pipes but not to the engine. Bleed. Check that the injectors are all spraying but keep well away from the ends of the injectors. If not sort out the fuel system. If OK refit everything and try to start.

 

In the event of no joy have a look at the air inlet.

 

N

[David Schweizer]

IIRC i measured one about 6months ago as 42.5 mm - the nearest sizes are 1"W = 1-1/8" BS which is 42.42 mm

or 1 -11/16" AF which is 42.86mm - I managed to borrow a 1-11/16" AF socket which did the job, however as richard

sugested turning the flywheel with a lever in the ring gear is hard work but if you can turn it then it isnt seized solid so

I would go along with the idea of sorting the starter and see where you go from there

 

springy

I had to remove the crankshaft pulley on our BMC 1.5 a couple of years ago, and I know I had a spanner in my box which fitted. Looking at them the most likely one was 1 1/4" AF

Edited April 15, 2011 by David Schweizer

[Sir Nibble]

Nah. The engine was running- it stopped. Something was/is not right with the engine.

Would have to be a hell of a coincidence wouldn't it, the two not being related.

Theory, starter ran on in mesh, it happens. Starter armature burst (usual) and shredded field coils. Starter becomes effectively solid copper, battery voltage falls, run solenoid drops out.

This does rely on this engine having a run solenoid which would not be usual but is more likely than coincidence.

[springy]

I had to remove the crnkshaft pulley on our BMC 1.5 a couple of years ago, and I know I had a spanner in my box which fitted. Looking at them the most likely one was 1 1/4" AF

 

 

My boat has a 1.8 bmc which is a smaller bolt than the 2.2 - thats why I had to borrow a socket to replace the crank seal on a 2.2,

dont know if the 1.8 is the same size as the 1.5.

 

springy

[WotEver]

Would have to be a hell of a coincidence wouldn't it, the two not being related.

Theory, starter ran on in mesh, it happens. Starter armature burst (usual) and shredded field coils. Starter becomes effectively solid copper, battery voltage falls, run solenoid drops out.

This does rely on this engine having a run solenoid which would not be usual but is more likely than coincidence.

How about (because this was my initial assumption on reading the OP)... starter ran on in mesh, it happens. Starter armature burst (usual) and shredded field coils. Starter becomes effectively solid copper,stalls engine.

 

No?

 

Tony

[Radiomariner]

Would have to be a hell of a coincidence wouldn't it, the two not being related.

Theory, starter ran on in mesh, it happens. Starter armature burst (usual) and shredded field coils. Starter becomes effectively solid copper, battery voltage falls, run solenoid drops out.

This does rely on this engine having a run solenoid which would not be usual but is more likely than coincidence.

 

I put forward the possibility that the engine stopped first, siezed. Attempting to start a siezed engine may in turn cause damage to the starter motor

Edited April 15, 2011 by Radiomariner

[canaldrifter]

Why would a seized starter motor stop an engine that is already running? It shouldn't be engaged.

 

Something has nipped up. That's why the starter can't now turn the engine.

 

I go along with slackening the injectors and trying to turn the engine on the alternator belt.

 

If it turns once cold you may be OK. My guess is it won't.

 

Regrettably, that would mean engine out and a rebuild.

 

Tone

[WotEver]

Why would a seized starter motor stop an engine that is already running? It shouldn't be engaged.

From the OP:

my neighbour became convinced it was the starter that had jammed/not cleared properly

 

It's not unknown for starter motors to remain meshed - vehicle fires have started that way.

 

Tony

[canaldrifter]

From the OP:

 

It's not unknown for starter motors to remain meshed - vehicle fires have started that way.

 

Tony

 

 

Yup. thanks. Re-read OP and now have caught up.

 

Tone

[David Schweizer]

I had to remove the crankshaft pulley on our BMC 1.5 a couple of years ago, and I know I had a spanner in my box which fitted. Looking at them the most likely one was 1 1/4" AF

We were on the boat last week, and I found the socket spanner I used to remove the pulley nut - 32mm

 

A bit late but hopefully helpful.