Oil related breakdown

1974 Commando: I broke down on the freeway. Just lost power, downshifting didn't work as the back tire locked when I let out the clutch. When I got home I saw that the oil had drained completely. The hose from the top of the cylinder/valve assembly came off the banjo bolt down below and I think the oil drained out. I reattached the hose (with a grommet so it won't come off again), put oil in the tank, but only got a few false puffs out of the engine when trying to start it up again. Can't get it started. Any advice would be greatly appreciated. Thanks!!

First, I would get some oil into the cylinders through the spark plug hole before rotating the engine. Then, can you develop some reasonable compression? Just by the feel in your leg you should feel if there is some. If you find some, the next step is a visit to the church, mosque, or temple of your choice. If you find none, you should check your credit report.

Crapola sorry to hear your broken heat heart, but first thing I'd try is new spark plugs. Lots of stories of heat sezied C'do's getting going again a long ways so maybe you too soon. If no joy pull head to check wrapped binding valve stems or seating sealing issues. Glad tire didn't get oiled to snap down. If rear was stil locked on clutch pull in - implies gear box issue too. Love em or leave em eh.

Thanks for the replies. I've got compression (and a penchant for hyper extension on the knee). I'll change the spark plugs, although I saw spark when I checked (It could have been stronger perhaps). I've ordered the tri-spark ignition and coil set out of Australia to see if I can get a better start on the kick. It's always tough to start.

Compression
Fuel
Ignition
Timing


It should start. See you in church.

Unfortunately, if the engine seized from lack of oil, it now has major damage. Running it any more will just cause more damage. It's time for a teardown. Jim

Can you say "hosed" ?

Unfortunately, if the engine seized from lack of oil, it now has major damage. Running it any more will just cause more damage. It's time for a teardown. Jim


Yep, sad to say, running it (if you can get it to run) will only cause more damage.

comnoz said:

Unfortunately, if the engine seized from lack of oil, it now has major damage. Running it any more will just cause more damage. It's time for a teardown. Jim

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I agree with this for sure. You may have lucked out with just piston to cyl seizure and you may be able to get it running but it will be noisy. I seized my engine once (different reason) and luckily it got me the 25mi home with only damage to the pistons. The cylinders could be cleaned of the aluminum transferred from the pistons and then just a honing and new same size pistons brought it back up to snuff. Many more miles would have damaged the cylinders causing a re-bore to be needed. With the barrel off and pistons out you can get an idea of how easily the crank turns. It should turn like silk. If not suspect main and or rod bearings, gulp! Still you can minimize further damage by not running it.

Id think the condition of the oil would be of intrest . ( Wot Oil ? )

Drain & inspect tank . Throw a comp guage on cylinders .

AFTER HAVEING cleand & filled tank & primed pump .

If the oil was old sh*t , its likely worse . New it might be ok .

Timing cover iside inspection mightnt be a bad idea.
If your lucky it overheated EFORE the Oil Ran Out .
otherwise its danga danga daga .

Matt Spencer said:

Id think the condition of the oil would be of intrest . ( Wot Oil ? )

Drain & inspect tank . Throw a comp guage on cylinders .

AFTER HAVEING cleand & filled tank & primed pump .

If the oil was old sh*t , its likely worse . New it might be ok .

Timing cover iside inspection mightnt be a bad idea.
If your lucky it overheated EFORE the Oil Ran Out .
otherwise its danga danga daga .

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Nope. New oil, old oil.... if it runs without, it doesn't matter if it was pure Maiden Oil in there or Wal-Mart 5-30. No hydrodynamic bearing... no joy. Game show buzzer.

I'm afraid I'm in the "tear the engine down" camp. From your description, all I can think of is how bad the rod bearings, cam lobes, lifters, piston and cylinders can get from running without lubrication. But then, I'm a bit anal about that sort of thing. You can always take a chance and try running it a bit to see. Chances are you'll just make it worse, but it's your call, and you might be lucky. The only Commando engine I've experienced with a similar history was one I built for a friend, and he installed it with the oil lines reversed. Got a couple blocks before it stopped. I wouldn't work on it again, but he told me later that he had to have it pretty much rebuilt, except for the head. I hope you have better luck with yours.

Ken

Perhaps this is relevant:


best-place-connect-oil-gauge-t18432.html

No argument best course is stop riding and get to wrenching but wouldn't ya-we want to know what it sounds and acts like if ya can get er started. May help train our ears too if a video taken, if ya can get er started. Check sump magnet if ya got one and open oil filter if ya got one too. Peer into plug holes and see if Al flecks or other unusual sights. If it does run w/o unusual noise or smoking up the joint - just what extra bad juju could happen if riding it while planning and collecting known renewal parts? Of course the dread of stranded again would tighten my groin too much to go far or somewhere I had to be, ugh. Betcha the main thing most worn down will be one or more of the exhaust lobes and matching lifters. ugh, I've spent most my C'do time recovering from something major. At least its not blown up nor crashed with legal hassles to boot.

Smashed the sump of the old car on a huge pothole driving down a by road in France - big bang! Clutch in, engine off and rolled to a stop, large oil slick. Motor went on to 1/4 million miles.
Drove a works van, which someone had drained the oil and not refilled, out the yard - got less than 100 yds before all crank bearings were toast.
Lots of bits of engine will survive on oil mist, but plain bearings are not one of them.
Check your crank.

What Id said is if BEFORE the OIL RAN OUT , it overheated and ' siezed ' ( the cylinder nipped up ) as its just possable it was a slow leak . if it was a pin hole in the tube .
Which sounds highly unliely as he said it CAME OFF . ( bugger ) If slow the remaining oil wouldve got hotter and hotter as it deplenished . So shoulda smelt it .

MOREYS and the likes a bit of protection , but more for overheating or a lap or two on a holed sump , if the checkeured flags in sight :twisted: .
Run a engine over the mountains on new Valvolene , up the last one with no water left . Highly relieved to get to the lookout overlooking Gisbourne .
Fully laden 2.3 L Bedford ohc van . 80 miles on that oil & it was sewerage . But it HAD protected the Engine . New head & it Used No Oil .
Overheating a Austin 2L ohc on the motorway for a 1/2 hour with no water ( crawling , off & on ) Same New Oil , and it wasnt siezed .
However it cooled 1/2 hour before itd turn on the starter , and a hour before it was hand holdable . Detensioned the RINGS with the prolonged heat .
But NO actual gauling / siezeing . Just Thermal Expansin clearance closure . :lol: Might mention it was the electric float thingo on the carb
that was the shit , despite experts whineing about everything BUt that . :x The montegos arnt bad old cows , as far as bad old cows go .
Being British nobody maintains them , then says theyre junk if they play up . Sounds Familiar Somewhere . ??

a BIG BRIGHT 200 watt Oil Pressure WARNING LIGHT , even with a guage , is pretty hard to ignore . IF its in your Line of Sight . ! so boths better .

trevorlikesnorton said:

1974 Commando: The hose from the top of the cylinder/valve assembly came off the banjo bolt down below and I think the oil drained out.

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Same thing happened to me while I was in the driveway warming up the bike. That's why I now have a stainless rocker line. The one that failed was relatively new.