Engine-HELP please

This area is for discussion/information on the "modern" AJS motorcycles manufactured in China from 2006 onwards.
maffers2012
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Engine-HELP please

Post by maffers2012 »

Hi i am 16 and i have a AJS JSM 50 and i have had it since January this year. It has been running fine up till now. 3 days ago i was using my bike as normal, i had been on my bike like normal but as i was on my way back from the shop i was pulling into my street and ass i did i just lost all power and my bike died. i tried starting it again and it started but not very well, but when i pull the throttle the engine dies. i looked at the air filter and it looks OK, i have changes the spark plug. i found out though that if i get it to 4000RPM it is not to bad and is kinder ridible but not safe and not practical as i have to keep it in high revs. earlier though when i was changing the spark plug i covered the air filter hole and it went straight to 400Rpm, i am really confused and need my bike to get me to college and work. can anyone help me and tell me what is wrong with it? PLEASE HELP
Edited by - maffers2012 on 17 Oct 2012 11:08:16 PM
J.Matthewson
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dave16mct
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Engine-HELP please

Post by dave16mct »

Its a bit difficult for most of us to help with this one. I've had a look on ebay what a JSM50 actually is. So it looks like a water cooled 50cc fuel injected? Is it putting any smoke out, if so what colour? Could there be a fuel filter thats blocked? Have you put oil in (I presume theres an oil tank, you don't mix the oil with the petrol?) Is the exhaust choked up?
Dave.
maffers2012
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Engine-HELP please

Post by maffers2012 »

yeh it is. yeh but it allways puts out smoke when i start it up and i think it is a white sort of culour. i haven't checked the fuel lines because when it is in high revs it seems to be ok, it can be a little boggy at times though. but there is oil and enough petrol. i am not sure about the exhaust but again when it gets to high revs it doesn't seem to bad.
J.Matthewson
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dave16mct
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Engine-HELP please

Post by dave16mct »

The colour of the plug you took out might give a clue as well. If its white its running weak, black indicates rich mixture. Should be a nice brown colour. Sorry I don't know much about 2 strokes- haven't had one since I was 16 (long time ago!) Dave
maffers2012
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Engine-HELP please

Post by maffers2012 »

when i took the spark plug out it was black, it looked like general ware to me though, but why when i covered up the air intake did the engine go straight to 400Rpm?
J.Matthewson
SPRIDDLER
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Engine-HELP please

Post by SPRIDDLER »

quote:
but why when i covered up the air intake did the engine go straight to 400Rpm?

Do you mean it slowed to 400rpm or speeded up to 400rpm? (400rpm is a slow tickover speed).
It would be quite normal for it to slow down when you covered up the intake as you are excluding air which would cause the petrol/air mixture to be too rich (and cause a blackened, sooty spark plug).
The white smoke could be steam (water-cooled engine) so do you have to top up the cooling water frequently?
One the many many things is that it's possible that the spark plug is failing.
As Dave has said, most of us will be guessing as we know little about your 'modern' Ajay. Diagnosing faults online is terribly difficult - No disrespect to you (I can't work an iPhone) but it's more difficult to help as you don't (yet) have the knowledge to identify the cause of the problem*. Sadly, it seems that none of your pals or local 'professionals' can or are able to help. We'll help as much as we can but you really need a local mentor at your elbow.

*Later
You have the additional problem that many of the components on modern bikes are of sealed for life, factory pre-set and non repairable throw-away construction. Substitution with a known good item is often necessary to locate the faulty item, but obviously it can be expensive as you may change many parts before finding the fault.
Most of the components on our 'old' bikes can be checked by eye and repaired/adjusted.Edited by - SPRIDDLER on 18 Oct 2012 09:14:54 AM
'There is a tide in the affairs of men
Which taken at the flood............'
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bigwol
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Engine-HELP please

Post by bigwol »

It could be that the feed pump for the 2 stroke oil is playing up and putting too much oil through at lower engine speeds causing the plug to foul.
Is it fuel injection or carburettor? Some 50cc bikes still are. If carb did you run the petrol low and get some rubbish into the carb which might have blocked up drillings or the jet for the slow running side of things?
Although you can never be sure it does sound more fuel related than spark to me.
Good luck!
It's all just riding motorbikes
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Merlin
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Post by Merlin »

white smoke can indicate water in the cylinder.
Chemists do it with test tubes
maffers2012
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Engine-HELP please

Post by maffers2012 »

thank you all for your help but i fixed it with the help of my cousin and his mate. it was the throttle needle in the carburetor, it had come of and wasn't moving when i pulled the throttle.
J.Matthewson
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tr7dan
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Engine-HELP please

Post by tr7dan »

Nice one Maffers

doesn't it feel great when you fix it yourself without having to take it to a garage - be warned though..... it gets addictive

Dan
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