1e40qmb piston problem?

[ice]

hi, i drive a keeway xblade (it’s very similar to f-act 50) and i recently installed a 70cc cylinder on it but won’t run no matter what, the only time it ran was for 5 minutes in idle then i wanted to break in the cylinder and not even 100 meters later it turned off and won’t start ever since, someone please help

[aeroxbud]

Are you still getting good compression? Does it feel easy to kick over?

[ice]

yeah i have compression, i tested it with my thumb and the scooter sounds like it has compression and wants to start but nothing, also today i opened the cylinder and the piston has very minor cracks and idk if its a issue or not

[zerotothirty]

If you haven't yet, check your plug wire and make sure it didn't fall out

[ice]

the plug is fine and gives a nice spark and i made sure it’s snug in there

[ice]

i have spark compression and fuel, i cleaned the carb a billion times and i even tried spraying carb cleaner in the spark plug hole and still nothing.

the only time it started was for 5 mins after the cylinder was installed and i drove it for abit and bam never started again, i have been trying to check for everything else in the past week but everything’s fine so idk if the cylinder is bust or what

also one of my head gasket nuts won’t tighten fully it just keeps spinning and when i try to take it off it gets stuck at angle and then whole long thingy comes off

i don’t wanna take it to a mechanic cuz mechanics here are shit and all they did is lose parts and be lazy and mess up something else

[ice]

Jun 14, 2024 12:57:40 GMT -5 aeroxbud said:

Are you still getting good compression? Does it feel easy to kick over?

oh and no there’s the standard resistance when trying to kick it

[ice]

anyone please? i’m gonna buy the new piston tomorrow so i wanna make sure if that’s the issue or should i sand the cylinder head ( because the previous piston might’ve left metal residue from breaking) or what?

[aeroxbud]

It looks like the small end bearing or one of the circlips has come out and damaged the
Piston.
Any damage on the head?

[ice]

Jun 16, 2024 15:56:58 GMT -5 aeroxbud said:

It looks like the small end bearing or one of the circlips has come out and damaged the
Piston.
Any damage on the head?

no the circlips are still in place, and the bearing wasn’t there so i replaced it and still not starting, the head looks fine just a few debris, i will send a picture of it tomorrow morning but it looks fine, so what should i do? does have anything to do with the cylinder head nut that’s not screwing on properly?

[aeroxbud]

You either have a stripped stud, or nut. Or the stud is loose, if it's not clamping down. Put a pen mark on the stud so when you tighten it you can see if it spins.

[ice]

this is the cylinder head, i also have to wait for the new studs to arrive 

[ice]

i managed to get the stud and still not working, there’s compression, there’s spark and fuel and air but still not starting
these are 2 different spark plugs, new and older one and both have spark

[aeroxbud]

Are you sure the head is sealing properly with that damage?
Have you checked the reeds? Perhaps that damage is from one of the screws holding the reeds in.

[ice]

Jun 17, 2024 11:00:53 GMT -5 aeroxbud said:

Are you sure the head is sealing properly with that damage?
Have you checked the reeds? Perhaps that damage is from one of the screws holding the reeds in.

yeah it looks like it’s closed very tight, how should i check for sure, and how do i check the reeds? should i open up the valve intake? because from the cylinders view it seems like the flywheel is turning fine and the wrench looking thing isn’t damaged