No oil...

[cfh85]

Made the novice (idiotic) mistake of not checking my oil regular, or rather, since I've had it - 2/3 weeks.

Anyway, engine stopped whilst I was doing 50mph today. I pull over, put it in neutral and carried on. About 5 minutes later I checked the oil - empty. I've now drained out what was in there and topped up.

The bike now sounds different - more knocking I would say. It's blowing out some smoke. The throttle response feels about the same though - could just be because it was running dry before.

I wont be taking it to a garage as I've done loads of work on car engines. I would, however, appreciate any advice on what to expect. What is likely to need fixing/replacing?
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Current bike - Honda CBF 125
CBT - 13/01/13

[Wafer_Thin_Ham]

What colour smoke?

Blue? If so it's burning oil, suspect knackered rings.
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[cfh85]

it's a bit late to rev it up now.

It smells like oil though.

If it is the rings what can I expect on my way to them? Head gasket? I'm assuming it's similar to a car engine?

Any ideas of what is needed for a full engine refurbishment?

I don't know my way around bike engines but I am confident to do all the work. I just want to make sure I have all the parts before I start taking it apart

Am I likely to be causing further damage by driving it?
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Current bike - Honda CBF 125
CBT - 13/01/13

[TomGT]

[Wafer_Thin_Ham]

Basically you'll want to inspect the whole way down the to crank I would suspect. Check those bearings for damage, and work back up from there.
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[cfh85]

[Shaft]

[cfh85]

Not all car engines are the same...

An example of which would be the wankel engines. Not adding oil would cause damage quite quickly, but once the inside of the cylinder has worn down enough it won't get further damage. The design makes the engine more resistant to catastrophic failure.

I have an understanding of how the engines work (obviously not like wenkels) but no clue as how they're put together.
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Current bike - Honda CBF 125
CBT - 13/01/13

[TomGT]

If you're splitting the cases get a haynes manual

[Kickstart]

Hi

Most bikes use a large number of plain bearings which need good oil pressure to work. Not enough oil pressure and the bearings are dead. If you have run it out of oil then almost certainly the engine will need a complete strip to replace all these bearings.

Add to that probably a load of excessive heat wrecking other engine components.

Roller bearings are more resistant to damage from low oil pressure, but that won't help from over heating caused by a lack of oil.

Most of the time it will be a lot cheaper to just buy a 2nd hand replacement engine.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[_Iain_]

Given the cost & associated ballache with rebuilding it, I'd be inclined to get a breakers engine & run that one till it actually went & kersploded.
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Please be aware that the above post may be full of complete nonsense.
Riding: '07 KTM Duke II, Baotian BT49QT-20 Driving: '88 Volvo 340

[Shaft]

[smegballs]

IIRC once bearing surfaces have started to be fucked from no-oil, the metal transfer process will continue even once proper lubrication is maintained. Even after you have oil back, you now have two rough scuffed surfaces rubbing together rather than smooth ones.

[spaz]

[cfh85]

[stevo as b4]

As said if it's run dry of oil, the engine is mostly fucked TBH. I suppose if it still runs now with plenty of oil, you could keep using it if really desparate, but as other's have said the bearing surfaces will have picked up, and any plain bearings including the big end will now be mullered.

The thing is that you probably still have some salavgable components left inside the motor, and if you stop using it now, then there's a fair chance less stuff will have to be replaced. it could be the difference between fitting new shells to the crank bearings and away you go, or having to throw the crank in a skip and replace that too. The worst thing is that your still probably going to ruin the top end Cams/followers by letting all the metal particles in the oil be forced up into the top end. it could fuck the oil pump as well.

If your not lucky all you might be able to save from the original engine is the crankcases, the block/barrel and maybe the head casting if the cam bearings are replaceable?

I bet there's at least £200-300 worth of bits to replace inside the motor as it is!

[smegballs]

If I was you, I'd give myself a slap for making such a noob mistake, chalk this one up to experience and start looking for an 2nd hand engine to flop in your bike.

By all means strip down the fucked one, to have a look, but I wouldn't entertain the idea of building it back to a useable standard - especially if you need a reliable bike for work commuting etc.

I'd find it very difficult to trust an engine that had been run dry, even if the subsequent damage had been supposedly repaired. There can be still be fucked components, or damage that might not be apparent until several thousand miles later.

Think of it from the perspective of going to buy a bike. The guy says, "well it was run without oil to the point of engine failure in the past, but don't worry it's been repaired....". Chances are that you'd walk away and find another bike....

It may be good to go for several thousand miles or it may fuck up a few miles down the road after you've spent hundreds on rebuilding it. A friend of mines dad had the big ends go on his Evo, on its maiden trip out after spending months in his garage with a total top-end rebuild. He reckons there must have been a speck of shit in the oil pump - a few miles down the road and the knocking started. Apparently tears were shed.

[mr jamez]

[delsol]

[smegballs]

[Walloper]