Doom and despair

[Mosin]

I Was out enjoying a lovely winters ride yesterday and the bike was running beautifully, purring along at about 60 mph. Suddenly and without warning there was a metalic bang and the engine cut out. Curiously the back wheel didn't sieze and I tried to bump start it as I still had some good momentum, but it was having non of it.

A call to the RAC saw me being recevered home. 

The engine now appears to be siezed, although it will turn over on the kick starter, it is very very stiff and there is no way it is going to fire. I had hoped that it might free itself as it cooled down but this did not happen.

Before I start taking it all apart, can anyone offer any possible explanations or things that I might be looking for? Or failing that, just a shoulder on which to rest my head and weep?

Simon

[a10 gf]

What a pity, with hopes for a speedy fix, mobilize to go on with the job, and posting your findings may give some slight consolation in helping others to maybe avoid enduring the same experience. Best wishes.
e

[bsa-bill]

Hi Simon - sorry to hear of your misfortune.
I have not experienced an Engine seizure but have heard of few mechanical mishaps at work and so I wonder about your description  of what happened, a metallic  bang? , I just have an idea an engine would screech to a halt if seized, others will have more knowledge about this.
Anyway if there was a metallic bang I would go careful at the moment until you find the cause in case you do more damage turning it over.

All the best - Bill

[G/F DAVE]

Hi, Simon first thing I would do is to remove primary cover then the primary chain to see if it is engine or gearbox problems then go from there. With a bit of luck it might be something simple to fix as you say it did not lock up rear wheel. All the best Dave

[RichardL]

Simon,

First, DON'T GIVE UP! The bike you ultimately have in top running order will be even more precious when you know more of its nooks, crannies and idiosyncracies, having done the upcoming work. Sounds like a marriage, almost, so don't let your wife read this. Anyway, very sorry to hear that the joy of riding must end for a while while the joy of repair and rebuilding takes its place.

Dave's advice about looking in the primary case is great and, hopefully it ends there. However, I think I must tell you that the failure you've described sounds an awful lot like that which I experienced after doing the first rebuild on my engine following 24 years of setting untouched (the bike, not me). That was a full top and bottom-end rebuild, except I was ignorant of the sludge trap in the crankshaft and did not clean it out. After running very nicely for somewhere under 100 miles, there was suddenly a clonking and engine stoppage. The engine was not frozen and I was able to get it restarted and clonked my way home (about 1-1/2 miles). To make a long story a bit shorter, the left-side rod bearing had burned partially away. I don't think it siezed and spun, because the rods didn't show that kind of damage. I hope I am wrong (as I so often am) but it sounds to me like one or both of your rod journals may have been starved of oil for any one of the many reasons that have been described in this forum. Without trying to recite a herd of them, I notice, having gone back through your posts, that there was a bunch of red silicone used on your timing cover at one time, that's just one of the possibilities.

Good luck, keep us posted and picted.

Richard L.

[Goldy]

If there was a metallic sound and it still turns over, I would have thought that something has come loose not seized. Possibly cush drive nut, clutch centre nut etc. ,at least you will have something to do on the cold winter nights instead of watching tv. All the best.

[LJ.]

Awww sorry to hear of this, coming back from my own winters ride and having thoroughly enjoy doing that I feel sorry that this has happened to you. However... You have a whole wealth of help and information here for when remedy starts, dont leave it too long. Hopefully the problem is simple and quick to fix. Keep us posted on what you do and find, its a great learning curve for us all.

[brackenfel]

Simon,
Sorry to hear of your problems.. If the back wheel didn't lock this is a good thing , if only for the fact that it didn't throw you off, especially at 60mph!

I'd repeat what's already been said - have the primary case off & look in there in case something has made a bid for freedom.. Also check gearbox operation..

Hoping you'll find something straightforward and cheap to fix..

Adrian

[Mosin]

Thanks for all the support - be it technical, spiritual or emotional!

As suggested this afternoon I have removed the primary case and chain and established that the seizure (I'll call it that for want of a more accurate diagnosis) is well and truly in the engine rather than the gearbox. Next I replaced the primary chain and removed the tappet inspection covers to check that all the valves were still in place and opening and closing correctly - they seem to be. Finally (for today), I removed the timing side cover just to make sure that there wasn't anything broken and jamming in there. Other than the fact that there was quite a lot of oil around the oil pump which all dropped out on the dining room floor, everthing in there seemed to be fine. The engine is still turning over on the kick starter, but it is so stiff that I cannot do this by hand. I am having to put my full 13 stone weight on in to get it to turn over.

It's starting to look like head and barrels off next isn't it..........?     

[LJ.]

Plugs out and have a look inside with a good torch, might reveal clues...

[1660bob]

"there was quite a lot of oil around the oil pump which all dropped out on the dining room floor"
Simon, your a star!!!!,
Yep, I suppose its barrells and head off next to discover the awful truth, but make sure you cover the sideboard with a back issue of Old Bike Mart before you dump them on there!!!!!!!

[muskrat]

G'day Simon, a very disheartening feeling, I know. A process of elimination is underway. Drop the sump plate and see what we have. Hopefully not big bits. Is there any movement (up & down) of the main bearings or excessive end float ? Wind over till pistons are 1/2 way down and insert a screw driver through plug hole and push down on piston. any movement ? If none found there it might be a broken ring or wayward gudgeon clip.
I'm afraid it does sound like siliconitis.
Best of luck.

[Mosin]

A bit of progress... perhaps...

Yesterday when I removed the primary drive chain in order to establish whether the problem was in the gearbox or the engine, I pressed down on the kick starter and it moved freely and I used this as the basis for my assumption that the problem was therefore in the engine.

A conversation with an elderly friend today suggested that I remove the primary chain again and rotate the engine directly from the cush drive nut with a large stilson wrench. I though that this seemed a bit unnecessary, but I decided to give it a go if for no other reason than to establish the cause of the fault once and for all. However, as I explained to him, I was a bit reluctant to take the primary chan off again because "it is such a pain to get back on again". His instant retort was "how bloody tight have you got that chain?"

I had never really considered the primary chain tension and have certainly never touched the adjustment as long as I have owned the bike (seven or eight months or so). Sure enough, it was almost rigid with tension and certainly not exhibiting the recommended 1/2" play.

Likewise, when I put my stilsons on the cush drive nut, the engine seemed to rotate smoothly, the valves all opening and closing correctly and the pistons going up and down just fine. I have now slackened off the primary drive chain and the kick start is suddenly much more free.   

Now I just need to put it all back together and see what happens.

Could my problems really be caused by something this simple? This week is proving to be an emotional rollercoaster and no mistake!

[mike667]

that would be quite sweet if that was the case - not sure why the bike would die etc unless the chain was so damn tight  - i would'a thought it would break first??
 are you still going to peer into what lies in the sump - it would probably give me a little piece of mind to see it nice and "metal" free

regardless hope for the best

[Mosin]

There's one other piece of information which I have neglected to mention as it seems totally unconnected. However, I might be wrong (it is not known)!

I have recently had my speedo reconditioned by AE Pople at 'Speedorepairs'. I fitted it to the bike and it looked lovely. About a mile before my engine calamity it stopped working altogether, despite only having clocked up 28 miles since I had refitted it.

I don't know if this is significant or not, but I just thought I'd mention it.

Simon