I have a 50cc two stroke mini bike (old) that will start but then seems to flood. The carby will shoot fuel out the side, but this is coming from the crank case as when i take the over flow pipe off the crank case, it happens there. I've blown the carby out with air and cleaned everything - all looks ok. It self mixes its fuel if that makes any difference. Cheers.
intrade,
Dec 23, 8:29pm
not mutch you said makes sense to me sorry.can you start again more clearly all i got is the carburretor is leaking or something and the oil gets mixed automatically!
mber2,
Dec 23, 8:33pm
the float cuts off the fuel to the carb when it is full so it seems it is jammed and the float is not cutting off the fuel at the correct level
bellky,
Dec 23, 8:36pm
Broken reed valve!
pettal,
Dec 23, 8:42pm
neddle and seat dirty ,or float has a hole in it and not floating enough to stop the petrol flow .
the-lada-dude,
Dec 23, 8:59pm
phisssst !
40wav,
Dec 23, 9:08pm
OK, here's what I found. Needle is all good, and the float is ok (checked with float bowl off and lifted, also float is not full of fuel). I've just drained the gearbox(!) and got 750ml of very thin, very dirty oily petrol. On the side is stamped '450ml'. I'm guessing this is supposed to contain normal engine oil. Correct!
kaspas,
Dec 23, 10:25pm
crankshaft seal blown!
daryl14,
Dec 23, 10:49pm
What sort of motor is it!
Some old two strokes had an inlet valve that was actually a wheel that spins with the crank and had ports to let your fuel/air mix into the crank case initially and then the down stroke of the piston pushed it up through another port to the top of the cylinder at the right time.
Could explain your fuel in crank scenario!
jmma,
Dec 23, 10:51pm
Sheared flywheel key (o:
intrade,
Dec 23, 10:56pm
it gets more wierd the crank case has not got any oil its a 2 stroke not a 4 stroker. the gearbox part would have oil and the gearbox and crank are sealed off from each other . so blowen crank seal would make it blow in to that compartment. for example.
meathead_timaru,
Dec 24, 12:55am
The only way fuel can get into the gearbox of a 2-stroke is if the crank seals are leaking.
supernova2,
Dec 24, 2:10am
Blown seal.Also no likely that gearbox would have engine oil.A 2 stroke enginedoes not have a sump full of oil but as you said mixes the oiul with the petrol.
Without knowing the make model etc I'd say it's probably not work fixing as in my experience crankshaft work on 2 stroke bikes can be very expensive.
meathead_timaru,
Dec 24, 5:40pm
Actually it would more likely than not be a 4T motor oil. I always used ATF in my 2-stroke road and dirt bikes for a nicer sharper gear shift. They're straight, not helical, cut gears so have no need for a high shear strength oil like a manual car transmission or differential.
the-lada-dude,
Dec 24, 5:55pm
where's that joke about the' blown seal '! hands up all those people who think it's a blown seal, . or .a seal blown!
daryl14,
Dec 25, 6:14am
I can't help but laff inside whenever my kids eat ice cream, Or blue lollies (like smurfs).
number 1 is the housing parts of the engine , number 6 is the oil drain plug for the gearbox oil the clutch isa wet one on that automaticengine Most times when a 2 stroker dont runs no more it is the piston and boor thats worn to death.
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