Disaster has struck !

[nasher123]

i broke down this evening on the A360 heading towards shrewton.

i was riding my varadero 125 at about 60mph, when all of a sudden the engine cuts out, and heavy engine breaking as if someone grabbed ur break

it would not start again afterwards, and when i managed to, it would have to be on full throttle just to keep it going at about 1000rpm

checked usual things, and petrol being the obvious, making sure there was a good spark no loose wires etc...

and then i decided to take the oil filler cap off, and there seem to be smoke coming from inside it. so could this mean disaster ? piston and rings have broken ?

your help would be very appreciated,

[StumpyFingers]

It sounds as if you ran out of oil. The engine will cut out and struggle to run if dry.

[Snaphappy]

Sounds bad, when did you check your oil last? have you noticed drips under the bike or has it been kicking out more smoke than normal

[nasher123]

no leaks whats so ever on the bike, i checked the oil recently and it was fine. but when i set off, it was running fine, starts first push on the button everytime.

i took out both the plugs, and they were a bit black on the ends. and checked the compression and seems ok.

what do you suggest i check ?

[StumpyFingers]

Black plugs and poor running would suggest the air filter is blocked.

[j]

smoking oil could also mean your coolant has run out and the oil has to do all the cooling and burns up.

[Freerangestormer]

Is your oil level still OK now?

Drain a little oil to check it's condition.

If you have a centre stand, put it on the stand, remove the spark plugs, engage first gear and turn the engine by the rear wheel, feel for tight spots. If that's OK then check for compression while turning. No centre stand, get help to lift the rear wheel carefully leaning it on the side stand.

Best I can suggest off the top of my head, take it from there.

[nasher123]

coolant level is between the marks. i must admit the air filter is due to be changed, and is a bit black. but wouldnt stop the bike dead when i am riding. one discoery i made was, tht if i pull the plug cover off the rear port it carries on running. so i have narrowed it down the rear port. oil and filter was changed about 500 miles ago.
so going to strip down the port, as my dad wreckons it could be the piston. but there is compression on both cyclinders and are even.

[Freerangestormer]

I think you can rule out the engine internals if it's turning freely and there is similar compression on both pots. Do both plugs have a similar appearance? When you pull the plug lead does it run rough (only one cylinder firing) or the same, try pulling the other plug lead if it runs rough then it's not that, if it stops then it's likely that is the only pot firing.

Check the oil, sample it, before you start stripping things down, think of it as doing a blood test! The fact that the oil was changed 500 miles ago means nothing, it's the condition that the oil is in now that might tell you something. 500 miles ago you didn't have this problem, make sense?

I feel it's more likely to be ignition or electrics related, you would get exactly the same the engine braking you reported if you hit the kill switch while riding along. If the engine was running out of oil you would most likely know about it as you would have started to experience more engine noise and higher coolant temperatures before this occurance and it would not have happened as suddenly as you describe, there would have been a gradual slowing as things started to sieze up.

If any engine has been running at normal temperatures, well loaded when you stop it and open the oil filler you will see 'smoke'. Unless it clearly is smoke from combustion of overheated oil, believe me you will be able to smell burning, it is more likely what you are seeing is simply oil mist / vapour caused by hot oil being sprayed and thrashed about in the engine crankcase, remember that crank is thrashing around and the pistons thumping up and down at up to 9,000 rpm, oil mist is not abnormal in itself.

Start elinimating things (turn the engine & test compression) and gather available evidence (sample the oil) to start diagnosing a fault.

Don't panic, not yet anyway.

[ChrisH]

Not quite sure what you mean by 'port' - however I wouldn't be in a hurry to strip anything down yet. The advice from Freerangestormer is sound and it seems from what you say it's packed up on the rear cylinder. It will run really bad on only one cylinder and have no power. That could be a knackered plug, coil or electrical fault like bad conection. Test for a spark. I'd start by replacing the plug on the rear cylinder and see if that's your problem...