ARIEL LEADER ENGINE PROBLEM

[alan.bedford]

HELP PLEASE WITH MY ARIEL LEADER I AM GETTING A TAD FRUSTRATED AT NOT BEING ABLE TO SOLVE THIS PROBLEM.
BIKE STARTS FIRST OR SECOND KICK AND RUNS FINE NOT SMOKEY AND WILL CRUISE ALONG NICELY 50-55MPH.COMPRESSION IS EVEN ON BOTH CYLINDERS AROUND 80 PSI 1ST PROD RAISING TO 125+. MY DILEMMA IS THAT I CANNOT TRUST EVER GETTING HOME OR WHERE I AM GOING.....SHE RUNS FINE FOR 20 -30 MINUTES DOESN'T MISS A BEAT AND THEN WHEN CRUISING ALONG AROUND 50 MARK I NOTICE AN INCREASE IN SMOKE FROM THE EXHAUSTS -ENGINE DOESN'T MISS A BEAT ,NO MISFIRES OR THE LIKE AND THEN ENGINE CUTS DECLUTCH AND COAST TO A HALT.
ENGINE KICKS OVER FINE (NO HINT OF PARTIAL SEIZURE )RUNNING ON API GRADE TWO STROKE OIL AT ABOUT 40-1 MIX,CHECK PLUGS NORMAL COLOUR NEITHER OILED OR WET,SPARKING FINE -FUEL IN CARB WHICH FLOODS WHEN TICKLED-TRIED TO RESTART EITHER NOTHING OR A HALF HEARTED FIRE ON BOTH CYLINDERS,SMOKE FROM EXHAUST BUT NO REACTION TO THROTTLE........PUSH BIKE HOME OR TO SAFETY !!!!!!!
LEAVE FOR 20 TO 30 MINUTES REPEAT ABOVE SAME RESULTS ....FOLLOWING MORNING FIRST/SECOND KICK STARTS RUNS EXACTLY THE SAME RUNS FOR 12 MILES STOP AT FRIENDS FOR HALF HOUR RESTART ABOUT 5/6 KICKS RIDE TOWARDS HOME AND TEN MILES LATER DITTO THE DAY BEFORE........HAVE JUST GONE TO BIKE 3 DAYS LATER FIRST KICK AND SHE IS TICKING OVER NICELY NO UNDUE NOISE NO SMOKE-?
IDEAS AND SUGGESTIONS (I'VE ALREADY BOUGHT THE MATCHES)

[john.nash]

these things run on a coil ? right ?

I had a honda XBR500 with almost the same symptoms.
Start, idle, run. About 30 mins later, dead.
Wait a bit.
Repeat.

Turned out to be my coil; breaking down when hot.

[nevhunter]

It does sound like the coil is breaking down. I've had symptoms like that before, and in every case it was the magneto coil. The smoke from the exhausts after a while may only be the accumulated residue of old oil/carbon in the muffler getting heated. Nev

[alan.bedford]

Cant see this as being coil as there are two seperate coils and condensers and if coil breaking down there would surely be misfire on at least one cylinder and for this to be coils both coils have to breakdown simultaneously without any hesitation off the engine so coils? ......the symptons (except for increase in smoke) are exactly what you get on a four stroke when you are silly enough to run out of petrol i.e the bike runs perfectly and then just stops clearly no reaction to throttle as there is no fuel. THAT SAID I just don't understand why if fuel related or for that matter electrical do I get the increase in smoke from exhausts, could this be that in fact my maths are very bad and I am running with too much oil in the mix,,,but again clean and dry plugs?

I was really hoping with all the two stroke ariels still in circulation someone in the Ariel Club would have been able to shed light on the matter but it does appear from the amount of topics on the two stroke forum that all the two stroke Ariel owners don't use the forum.

Put this message on the Francis Barnett club forum and have about a dozen replies most of which are suggesting a fuel related problem with one person suggesting it's the inner crank case seals......knowing nothing about two strokes especially about crancase seals DOES ANYBODY IN THIS CLUB HAVE A VIEW?

Thanks John and Nev for your response still hoping for more as currently she has been put to the back of the garage as I want to ride my bikes not push them!

Alan

[john.nash]

We cannot _make_ people own the two strokes AND use this forum.
We're only a 3 months old, here, and most seem to be fourstroke.

Might I suggest the two stroke yahoo group:
http://uk.groups.yahoo.com/group/ariela ... oup/?tab=s

[brenton.roy]

Hi Alan, While I don't have a Leader now, I have had the pleasure and know they are very simple. My dad had the adage for two strokes of compression / spark / fuel - must be OK..
The coil explanation is a good one - and your symptoms (bar the smoke) are exactly what occurs in this situation. Look for electrical component failure. Perhaps your battery is dying or something in the charging system failing.
Flooding would cause the smoking, but you would expect the most smoke when it starts later..
Have you checked that the breather in the tank cap is clear and that air can easily make its way into the tank?
Two strokes draw a fuel air mix through the crankcases. The pistons act as a vacuum pump to suck the fuel in. The oil you put in the fuel lubricates the crankshaft on the way through. This relies on good sealing in the motor. The crankshaft is an obvious weak link in this and if air gets past it, the motor will suck air from the primary rather than the carby (or from wherever is easiest). This is a possibility and will cause the smoking you are talking about if there is oil to be drawn in. The manual gives a pretty good explanation of how the seals fit. http://www.arielownersmcc.com/members ... 043-62.pdf .The centre seal separates what is effectively two pumps.
Over time, the two stroke emailers have drifted away from the four. John and Dave have set this group up with a clear intention of providing a worthwhile forum for everyone. It will take a while for those loyal to the original email groups to get the feel of how the forum works and move across. As much as we need their ideas, I expect we will have to be patient.
I hope all this helps.

[keith.hodgenia]

I would have a good look at the coils Alan. There are coils about that are designed to run with a ballast resister. These coils are designed to run at less than system voltage in normal use. When the ballast resistors are cold they let full voltage through, then as they warm up they reduce the voltage that goes through them. If you have these coils but no resister then the coils will over-heat and start to play up in the time frame you describe. It's worth looking. Keith.

[nevhunter]

If you are gettting oil past the seal(s)then the level will fall in the gearbox. The smoking exhaust I have experienced almost universally with mufflers on two strokes, that have been in service for a while and accumulate oily carbon which after a reasonable run puts out smoke when it gets hot.
If the smoke is directly related to the engine cutting, does it happen before the engine cuts or just after? Does the throttle feel as if it is not responding, and you open it up just before it dies. Does it go onto one cylinder for a short while or backfire at all? Do both pipes smoke? Nev

[Johnellis]

HI Allan
Have you rebuilt this engine with new seals, Are you using synthetic oil, Check the oil level in clutch as near side seal will draw oil if worn,Old seals are good when cold but fail when hot.

[alan.bedford]

Thanks for all your replies - the leader is still waiting for me to do something apart from run her to and from the shops just a couple of miles which she does without and problem.

To answer some of the points made - the bike has been subject of a restoration by previous owner a few hundred miles ago in the paperwork that came with the bike was receipts from Drangofly for new left hand and right hand con rods (complete) pistons +20 thou cranks balanced, new coils etc I therefore assume that new seals were also part of the rebuild.

Tank breather clear, I placed a new battery on her the day I bought her and it is fully charged and also immediately shows charge when revved with lights on. I notice the increased smoke about a mile before break down occurs yet when I remove plugs they appear to be dry and clean as if fuel starvation.

I didn't realise about the possibility of it dragging through gearbox oil so will check levels next time as from what people tell me that is also the way to determine if the crank seals are gone....if this was so would they reseal to enable me to start bike up the following day and ride to the shops?

BIG THANKS to those that have set this group up lets hope more people hear of the value of seeking help and giving advice as after all it is only by sharing info that we will keep these machines on the road.

Have spent the past week fettling the Square 4, Venom, Valient, and LE's all 4 strokes which I tend to understand a little better BUT I WILL have another crack at the Leader in due course but it will have to wait a little while longer as 11 of our classic bike club will shortly be off touring Wales.

Alan