Fozzie Posted August 5, 2014 Posted August 5, 2014 Maybe you have a spark but a weak one? Have you tried a new coil and battery?For example, Bikermoos CBF was turning over after it had diesel put in it, and the battery died, I ran it up the road with the plug out and the bike in gear to charge it back up over the course of an hour. And then it would spark but it was too weak to fire so needed to really be run hard down a hill.Coils often break down over time and steadily just die. Maybe you've lost the intensity of spark required to get good combustion. Quote
acting_strange Posted August 5, 2014 Posted August 5, 2014 i can see what you mean.,But the thing is.. this moped have been running flawless for the past couple of months, and then suddenly died to this...The valve timing cannot put itself backwards... The timing chain is on properly, and all in good condition. eeerrrmmmm wrong......a timing chain can jump and it only needs do so 1 or 2 teeth to be out... Quote
Guest Posted August 5, 2014 Posted August 5, 2014 i can see what you mean.,But the thing is.. this moped have been running flawless for the past couple of months, and then suddenly died to this...The valve timing cannot put itself backwards... The timing chain is on properly, and all in good condition. eeerrrmmmm wrong......a timing chain can jump and it only needs do so 1 or 2 teeth to be out... Like i said.. all is in time, and the chain is in good condition..and Fozzie:Had brand new CDI, spark plug and coil pack..I also thought of the weak battery issue, and tested it with my bike battery connected.. Still nothing.. Quote
Dav3y Posted August 5, 2014 Posted August 5, 2014 Blocked/Restricted exhaust ?Seems you've covered pretty much everything else. Quote
eastanglianbiker Posted August 6, 2014 Posted August 6, 2014 have you set the float levels in any of the carbs to make sure there is enough fuel in the bowl to get sucked in by the engine?,and also checked fuel pipe to make sure it hasnt collapsed inside restricting flow to carb and causing problem that way? Quote
Guest Posted August 6, 2014 Posted August 6, 2014 have you set the float levels in any of the carbs to make sure there is enough fuel in the bowl to get sucked in by the engine?,and also checked fuel pipe to make sure it hasnt collapsed inside restricting flow to carb and causing problem that way? Yeah checked that fella...Its has all brand new fuel pipes etc too..and Dav3y: exhaust seams fine fella..And yeah your right... I have checked every little thing! My mate has throw in the towel now, and gave up.. He is anoyed that he can repair scrapyard engines and bikes, but stuck when it comes to a moped!My mother is just going to saveup and get my little sister a 125 i think She is very good on them, As she rides my bike quite often Quote
Guest Posted August 6, 2014 Posted August 6, 2014 Could an earth be at fault? Nope.. Because if it had no earth, it would have no spark...And TADAAAA. finally. Found the problem!!!The keyway on the crankshaft had messed up..So the flywheel would slip.. Not alot, the keyway was slightly worn each side, just enough to miss-align TDC mark, every now and then...Thank F*** for that.. was about to give up on the thing a dab of weld to close up the wear on the key way, so that everything is held nicely.. and it fires right up Quote
acting_strange Posted August 6, 2014 Posted August 6, 2014 Could an earth be at fault? Nope.. Because if it had no earth, it would have no spark...And TADAAAA. finally. Found the problem!!!The keyway on the crankshaft had messed up..So the flywheel would slip.. Not alot, the keyway was slightly worn each side, just enough to miss-align TDC mark, every now and then...Thank F*** for that.. was about to give up on the thing a dab of weld to close up the wear on the key way, so that everything is held nicely.. and it fires right up Sorry but that doesn't make sense to no fuel getting in......makes sense for timing being out..... Quote
Guest Posted August 6, 2014 Posted August 6, 2014 Could an earth be at fault? Nope.. Because if it had no earth, it would have no spark...And TADAAAA. finally. Found the problem!!!The keyway on the crankshaft had messed up..So the flywheel would slip.. Not alot, the keyway was slightly worn each side, just enough to miss-align TDC mark, every now and then...Thank F*** for that.. was about to give up on the thing a dab of weld to close up the wear on the key way, so that everything is held nicely.. and it fires right up Sorry but that doesn't make sense to no fuel getting in......makes sense for timing being out..... Yeah i know.. But like stated.. With a little 50cc, A plug would barely get wet at all...and yeah, if it had put valve timing out a bit, then no fuel would getting in on the times it needs...But oh well. All fixed now.. My sister is happy once again Quote
Fozzie Posted August 7, 2014 Posted August 7, 2014 Sorry but that doesn't make sense to no fuel getting in......makes sense for timing being out..... A 0.05 litre vehicle struggles to get a wet plug so as I said before it probably is working, just the size of engine draws so little it would be hard to notice, and they are also very sensitive to such issues due to being so small. Basically the timing was out just enough the engine worked like an overpriced pump, pulling fuel in, not sparking in the right amount of time to cause an effective combustion to turn over, then spraying it out into the exhaust. Quote
Rod York Posted August 8, 2014 Posted August 8, 2014 Ive just read this post and was really scratching my head trying to think of what it could be. Congratulations on your persistence & reporting back to help others...so often ..after mucho help from others, there is silence- thanks for the update! Quote
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