back with smoke issue :(

[beginnerMX]

Hey guys so my bottom end was rebuilt from a mechanic and told him to check top end and to do that IF it needed it. Issue is iv put the engine back in the bike and put 900ml of fresh oil but its smoking like crazy! blue smoke! it idles fine for about 1 minute with smokey blue smoke and then just dies if throttle isnt touched, i did valve clearances but im not sure if i did it right i just pushed on the kickstarter untill it hit tdc i think? and then i did the clearances also noticed a little clean oil comming out of the exhaust valve hole engine is a LIFAN 150CC thanks.

Edit: Backfires when when throttle is applied OKO carb jets are 36/102 clip on needle is 2nd from top.

 

[Carlts]

Hey mate,

When doing the valves you really have to match up the timing marks....

Could be your problem?

 

[beginnerMX]

i saw the T mark but couldnt see anything to line it up to and there was no "force" where the T face the top was so thought maybe that wasnt TDC so did it the other way. Would incorrect valves cause bad smoking?

 

[nickv1980]

if its heading down into the cylinder via the exhaust valve could be a leaky valve stem seal .... 36/102 sounds a little rich on the 150 too

 

[Phil67]

incorrect valve adjustment will give you backfiring.
Smoke is from rings if you are saying it was just rebuilt. It may go away, but if the rings are in upside down your cactus.
Lower that needle to the middle and see what difference that makes too.

 

[rotn50]

Does the compression seem very hard and harder than normal to kick, valve stem seals maybe buggered allowing oil into the combustion chamber

 

[my67xr]

is the clean oil coming out from where you adjusted the exhaust valve?
if so that is ok.

my lifan 150 is running an OKO 26mm, #38 pilot jet, 100 main jet
the backfiring may be due to the pilot jet being a touch small?

 

[beginnerMX]

i use have always run 38/102 i just put a 36 in to maybe see if it smoked less, and yes it does seem abit harder to kick it gets stuck but then becomes easy a brand new kick start shaft was installed. I will do valves again and see how it goes. and report back tommorow

 

[motodevo]

Did you lube up the top end when you reassembled it(piston,rings,bore), i do and they smoke for a while until all the oil is burnt up. Also are you sure all the oil passage o rings(especially the head gasket one) went back in when you installed the top end? From memory(and its not the best) Lifan 150's only take about 700mls to hit the max mark on the oil window, check your window to make sure its not too high a level and make sure your breather hose wasnt squashed when you fitted the engine back in as that'll push oil through seals it normally wouldnt/shouldnt

 

[beginnerMX]

i paid a motorbike mechanic to rebuild it so im guessing he would of done it all right, i dont have a breather hose on the bike so that shouldnt be a issue?

 

[beginnerMX]

whats max on oil window? just to the top or?

 

[my67xr]

level with the red dot in the middle of the window is full

 

[beginnerMX]

there is no red dot? i took a pic

 

[my67xr]

ps; be sure to check it while the bike is upright too

just checked my other motor, no red dot.
the window has a silver backing in the centre section, full is half way up the window.

 

[motodevo]

the two marks next to the window are min and max when the bike is upright(not just on the stand),looking at your photo you have too much. When i said breather i meant crankcase breather hose, if its blocked it will pressurise the crankcase and push oil past seals