lifan 125 with no compression

[josh5150]

hey, anyone know what i can try to fix this, was wroking fine, the left it sit for a couople of months and now i cant start it, you go to kick it over and the kick start just drops with no resistance?? i put new piston and rings in it, cleaned the spark plug, don't know what else to rty???!! also is the coil supposed to turn when you kick it over?? any help would be appreciated...
Josh

 

[DvDRip]

put it in 3rd or 4th gear and push it along, is there resistance?

 

[josh5150]

125 engine with no compression

there is slight resistance, obviously more in first and gets less up to fourth. but not much more than if it was in nutrall

 

[roost666]

check your valve clearance

 

[josh5150]

I checked them when i did the piston and rings, only a visual, but they seemed to be seated properly. Is there any other checks I can do?? thanks

 

[headsmess]

is the engine actually turning over? sounds more like your clutch is slipping. the start in neutrals suck in that regard...

put a socket on the flywheel nut and turn it over. if it has compression then its the clutch. about $50 on fleabay depending on seller.... if not.... check the valve clearance. could be a bent valve, bad clearance, wrist pins shattered(seen that before) so the piston isnt moving at all, broken primary/secondary gear.....

start with the obvious. turn just the engine over should be a 14mm socket.

 

[josh5150]

i don't think it's turning over at all, I put the socket on there and there wasn't much resistance at all, when i kick it over the flywheel doesn't move either, is this normal?? I checked the clutch seems to be working, i cant even get a spark out of the plug??

 

[headsmess]

if the flywheel doesnt turn when you kick it over, its the clutch. even the splines in the clutch hub stripped out maybe?

moving on, it could be as simple as a foreign object, like a screw, holding one of the valves open...happened to my postie.

IF the clutch is ok, which it doesnt sound like it is...

should be able to tell if its turning over, no matter how you do it. thinking isnt being sure. even if you have to pull cam sprocket cover off to see, find out and be sure its only one bolt to undo...

another thought...snapped cam chain.

such a long list of things that can go wrong

 

[josh5150]

thanks headsmess, I'll have another go in the morning, at work now, the thing i don't get though is it was working great until i didnt ride it for a couple of months and now nothing, beats me. I'll check the clutch, is there any fuses or electrics that can cause trouble??
thanks again for your help
josh

 

[lionelmorrison17]

hi mate this might sound stupid but check your clutch cable where u can adjust it and make sure it hasnt come loose as this happened to mine and it was all floppy and had felt like i had stripped it
cheers lionel

 

[Cactus Jack]

I'd say they guys who said it's something to do with the clutch slipping have most likely hit the nail on the head ... Hopefully that's ALL it is ...

Another factor that is known to have happened after an engine has sat for a while is that thickened/glugged up oil or rust causes the valve stems to stick in the guides ... so when the engine is kicked over one of the valves goes down and stays down then gets hit by the piston which bends the valve head ... The extent of the damage all depends on how "sticky" the valve is ... so the stem can still be pushed back up by the piston but the tilted valve head doesn't seat properly causing loss of compression ... A valve could also be fully bent and acting as a piston stop and the clutch is slipping ... which is actually a good thing since it could have saved the cam chain from stretching or breaking , piston and head chamber damage etc etc etc as Headsmess has stated ...

The moral of the story is ... ALWAYS remove the spark plug and gently turn your engine over by hand via the flywheel after it's been sittin' for a while ... If you feel ANY tight spots ... STOP ... Don't force it to "get rid" of the tight spot ... LOL ... It's also a good idea to remove the valve covers and check that the valves are coming back up ...

For Chev engines I used a special tool (like a dummy distributor shaft) on the end of a drill to prime the oil pump before even thinking of attempting to start them ... Only when oil was flowing out of every pushrod was it safe to start 'er up ...

 

[unitrider08]

yea a valve crash