Blowing smoke after valve clearance check

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aero165

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Hi everyone,

I've just had my new bike (new to me) shipped up from Vic. When it was started last around 3 weeks ago it was running fine and wasn't blowing smoke.

As soon as I received it I checked the valves clearances and fired it up, it started blowing smoke almost instantly. I'm no expert on checking valves but the last time I did, everything worked fine. I'm sure I did it right. Find TDC, .10mm inlet and .15 exhaust etc etc.

There appears to be oil leaking into the exhaust manifold.

Does this sound like symptoms of a poor valve clearance check?
 
Any engine new should smoke while running for the first time (for a little bit) as because in assembly every component is coasted in oil

if its a butload of smoke after a while then you most likley need a new exhaust valvestem seal or inlet seal (cheap) but it means you need to take your head off (easyist way) or if you are feeling the need for a challenge you could probably do it with the head on the bike and pump compressed air into the spark plug holes to keep the valves from falling into the combustion chamber but i would not bother even trying that.

could be your rings also...
you could have dropped somthing into the head while adjusting the valves sheering the valvestem seal (sometimes common)
"Usually a china engine is .003 inches inlet and .004 inches outlet." 100%correct thats what you should set yours
also how did you find tdc?
did you do it by feel (wait for the rockers to loosen up)
or did you do it from the flywheel? (align the marks on the flywheel or cdi)
or did you do it by the markings on the cam gear (the best way if new to doing valve adjustments or motor works)
 
I readjusted the valves, this time without a beer in my hand and it's stopped smoking now. Woo

Thanks for you help eveyone
 
wait so to be clear... tappet clearance is also valve clearance... right? and i i have a lifan 138cc.. before i checked mine was a little smoke and the tappets where makin noise so i tightened the outlet and tapping sound gone.. but now its blowing white smoke and smells like a lawn mower.... running to rich maybe? and the engine bogs when i open the throttle to quick..
 
wait so to be clear... tappet clearance is also valve clearance... right?

Yep thats right :) Normally the tapping noise i made from loose tappets (i sue the term "normally" very loosely) What do you mean by tightened the outlet? AND FINALLY from what youv'e said above it sounds like a good start would be to set your tappets/valves to .003 and .004 and see what happens from there.
 
Yep thats right :) Normally the tapping noise i made from loose tappets (i sue the term "normally" very loosely) What do you mean by tightened the outlet? AND FINALLY from what youv'e said above it sounds like a good start would be to set your tappets/valves to .003 and .004 and see what happens from there.

put the feeler gauge in under the tappet and tightened it down until it just bites into the tappet... the bottom(outlet) tappet... but i followed a video which said .004 for inlet and .006 for outlet..
 
Did you lie the bike down or have it any other angle than upright when you did it? Also what colour is the smoke, definitely blue?
 
Did you lie the bike down or have it any other angle than upright when you did it? Also what colour is the smoke, definitely blue?

was on an bike stand on the bash plate.... white smoke no blue tinge... smelt like a lawn mower running.... and heaps of smoke... i did notice there was a lot of oil when i took the bottom cover off... enough to make a good sized pool on the bash plate...
 
White smoke can be a blocked crank breather also mate, was the breather stuck between the engine and frame.
 
put the feeler gauge in under the tappet and tightened it down until it just bites into the tappet... the bottom(outlet) tappet... but i followed a video which said .004 for inlet and .006 for outlet..

That'll be fine, maybe time for new rings :(
 
White smoke can be a blocked crank breather also mate, was the breather stuck between the engine and frame.

That was my second thought, blow by cos breather is blocked.

Valve seals are probably stuffed and not leaking enough into the chamber to make the smoke blue. Just ride it til it breaks, motors are cheap enough!
 
never thought about the breather hose to be honest... will check that now.. im hoping its not new rings or anything to do with an engine pull down.. dun want to break it.. lol
 
ok so defs not the breather... there aint even a hose on the spigot....
Def check you can feel air coming out the crank breather mate, just incase it is internally blocked.
 

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