Smoking engine??

[MiniMadness]

Hey fellas, I went out for a little ride today (about an hour) and on the way home I noticed smoke coming from the engine.... I'm not sure if it was coming out the air filter or what, because as soon as I saw it I killed the engine. The bike is probably just about on its second tank of fuel, has been ridden fairly softly for run it in and is just approaching the first oil and oil filter change. The thing is before the ride there was plenty of oil and at the end when I saw it smoking (after I killed it) I some, but not much oil left in it and oil leaked all over the bash plate...

What's the go? I look after the bike really well..

 

[brown-i]

did you go through all the nuts and bolts even before you rode it and tighten and locktite them all up?

 

[MiniMadness]

Yep, except not SOME engine related ones because you don't want to get loctite in the oil or anything..

 

[brown-i]

gasket gone?

 

[Dabomb]

running in soft is a bad idea!

 

[I_THUMP]

running in soft is a bad idea!

Agreed^^


Here is a quote from our resident 'Minirider Mastermind' (Cactus Jack) about smokey motors:

Sources of white /grey / or blue smoke are :

1) Poorly sealing rings on the bore wall ie rings or bore worn out of round , honing peaks gone without rings bedding in ... bore wall or rings scratched or gouged by grit ... Rings can also be stretched out of round during installation or removal and they'll never ever seal again ... Even if rings are carefully removed from a bore ... the cylinder MUST be re-honed for them to re-seal to a high degree again ...

2) Ring end gaps too big ... Ring end gaps not properly staggered or in the wrong position in the bore ...

3) Oil can leak past worn , damaged or incorrectly installed valve stem oil seals ... the symptoms are usually a puff of white smoke on start up that goes away or diminishes as the engine warms up ... oil leaks into the ports while the engine is sitting ... but the leakage rate is too slow to make smoke while the engine is running ... The engine can puff white smoke when the throttle is backed off since the cylinder vacuum sucks hard on the seals when the slide is shut off ... The same can happen if the ring seal is bad too ... only the oil gets sucked up from the crank case ... Oil mist or smoke blowing out from the dipstick or vents can also indicate bad ring seal / blowby ...

3) Bore scuffed from over heating ... the rings expand , the ends butt tightly together , the ring keeps expanding and forces too hard on the bore scraping the honing off and glazing the bore ... then when the engine cools , the bore is bigger than the rings ... it only has to be a micro thou bigger to be no good ...

4) Those junk thin steel shim gaskets that are supplied with some BBK's combined with the removal of the rubber O-ring and trumpet piece can allow oil to leak from the gallery into the bore ... Once again , the oil gets sucked into the cylinder on backing off the throttle from high revs ... Only copper or stock type gaskets which expand or crush unevenly can fill variances in between machined surfaces ... For a steel gasket to work , the machining would have to be perfect ... and that's pure fantasy without hand scraping and lapping each individual cylinder head to the cylinder ... They say to use Honda bond or some other type of hardening gasket cement , but anything like that can be blown out or crack and leak ... The very idea of using it to do the job of a head gasket is ridiculous ... and BODGEY ...

5) Even IF the parts were lapped to perfection ... the tensions of each cylinder stud would all have to be precisely the same and torqued in the proper sequence to avoid distortion ...

Bad ring seal or a blown head gasket causes smoking to get worse as the engine revs higher ... The colour varies from grey to white as the amount of oil getting burnt increases ... Only a rich fuel to air ratio burns black ...

 

[Poulsen8r]

I hate to point out the obvious but... is your sump plug still in? the smoke could just be coming from oil that has gotten onto the header...

 

[Dabomb]

lol...engine would of seized if the sump plug was missing!

check the valve inspection covers...especially the exhaust side....
run the engine and find out exactly where it is coming from, if there's enough oil in ur motor, burning some small amount of oil wont hurt it.

 

[Poulsen8r]

Yeah but there are so many places oil can cause smoke and there are so many places oil can leak from...

 

[Poulsen8r]

Oh, check you crankcase breather(s) also, i recently had a problem with smoke from my exhaust and it was because my crankcase breather was full of mud... they really should find a better place for those...

 

[Dabomb]

Yeah but there are so many places oil can cause smoke and there are so many places oil can leak from...

if the sump plug wasn't there...THE ENGINE WOULD SEIZE cause it would drop all its oil very quickly....

 

[WogBoi]

well if this happend to my bike i would start it up quickly ( 5 seconds ) and see where the smoke is comeing from.. i had a little hole in my exhaust and smoke was comeing out of there, oil was leaking on my side engine cover and bash plate,, so check your exhaust for holes

 

[MiniMadness]

Well I wasn't running it in tooo soft. I am just not the best of riders so have been taking it slow and to my ability. I drained the oil yesterday after this and will put in some good Motul stuff once I can find the right size allen key. Then I'll start it up and let you guys know whats happening. What if there is no smoke when I start it up? Does that mean everything is sweet to ride again or should I be replacing something?

 

[headsmess]

allen key? where exactly are you putting the oil IN from? um...
now smokings bad for you and your bike
does it have an oil cooler?
cam chain tensioner bolt loose?
cam cover loose? gasket rooted?
wheres the oil leaking FROM? (this should be fairly obvious.)
exactly HOW MUCH OIL do you call plenty?
over a litre is MORE than plenty.depending on what bike it is....
p i used motul once on my lathe and i swear it smelt like BRUT deoderant)

 

[MiniMadness]

allen key? where exactly are you putting the oil IN from? um...
now smokings bad for you and your bike
does it have an oil cooler?
cam chain tensioner bolt loose?
cam cover loose? gasket rooted?
wheres the oil leaking FROM? (this should be fairly obvious.)
exactly HOW MUCH OIL do you call plenty?
over a litre is MORE than plenty.depending on what bike it is....
p i used motul once on my lathe and i swear it smelt like BRUT deoderant)

IN the oil place.... On the lifan 150cc it's an allen key for some strange reason....
PitPro 150XR has an oil cooler.
Couldn't see where the oil was leaking from.
There was about 300mL - 400mL in it that I drained.




Just replaced all the oil with 1L of Motul today. Started it up and seems to be running like a charm. The quality of Motul is amazing compared to shipping oil...

Anything I should check now or just ride?

 

[headsmess]

ride it...
just keep checking that oil....and give it a good clean and try finding that leak.
and yep, motuls good stuff. just smells funny
didnt know about that allen key though thats just silly, needing a tool to check your oil.... lesson learned. china

 

[n1ck]

on some bikes when they come in from the containter they some times have a paper clamp on the
breather tube to prevent oil spill very stupid i know but it sure does make them blow smoke
but if its not smoking from the exhaust and is smoking from around the motor id say you have a oil leak some were

 

[davedonzella]

I'm gonna suggest blown head gasket. It happened on my old pitbike. I noticed it blowing smoke and on the way back to my ute it got progresivly worse until it died in the ass right at my ute (at least i didn't have to push it) and when i tried kicking it found it had very little compression. Me and my mate tore the head down and found this....

Replaced the head gasket and all fixed.

 

[MiniMadness]

I doubt it would be a blown head gasket. Started it back up and all seems good for now. I'll see how things go.

 

[full-factory-klx-rider]

i have a pit pro 110cc it is blowin a sh-t loads of smoke out the breather hose and has lost power can any one help oh yer have checked the oil level havent put too much in cheers