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02 CRF450 White smoke after new piston, ring and valves

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I have an 02 CRF 450R and I just put in a new piston, rings, valves and had a Honda shop cut new valve seats and installed new seals. I put the bike back together and have white smoke coming out of the exhaust. I put assembly lube on the wrist pin and motor oil on the rings and cylinder wall. I ran the bike for about 15 minutes total over 3 different days. When the bike is reved, more smoke comes out. When the bike is shut off, the exhaust looks like a "smoking gun." Any ideas? Thanks

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You oiled the rings, that's not the best way according to many experts, opinion varies...but, if you idled it or ran it slow for 15 minutes over 3 days to "break it in" then you did NOT "seat the ring" properly and you are not getting a good seal, letting oil past the rings and burning it.

Your BEST bet would be to take it apart and install a new piston ring BONE DRY to the cylinder....hone the cylinder lightly to get a fresh prep...then break it in the HARD way...

http://mototuneusa.com/break_in_secrets.htm

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The reason for the improper break in was that I saw the white smoke and killed the bike. I came back the next day and tried it again, this time riding it. The 3rd day I put a different plug in to see if it would make any difference. I put a very small amount of motor oil on the rings and a thin coat on the cylinder wall. The bike then sat for a week before I started it because I was waiting for valve shims. The piston was at top dead center so some oil would have leaked down into the crank, but still a small amount on the cyclinder wall. Would that make that much of a difference?

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Give the ring time to break in and seat correctly before taking it all apart again. Go out and ride it like you normally would and see if the smoking stops. If it does I'd say your good to go. Just my .02

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Give the ring time to break in and seat correctly before taking it all apart again. Go out and ride it like you normally would and see if the smoking stops. If it does I'd say your good to go. Just my .02

Try that first...if you still get white smoke, get new rings.

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I put a very small amount of motor oil on the rings and a thin coat on the cylinder wall. The bike then sat for a week before I started it because I was waiting for valve shims. The piston was at top dead center so some oil would have leaked down into the crank, but still a small amount on the cyclinder wall. Would that make that much of a difference?

From what I'm reading, no that would not have made a difference. My guess is that you didn't fallow or choose to go with the hard break in method. This is your choice, I go either way but choose to use the hard break in method on my projects. As long as the bike sounds fine and seems to be running fine I'd go ride it. The ring will take allot longer to seat using the warm up cool down break in method. If the smoking doesn't stop after a regular day of riding you might have a problem. Good luck and have fun. :applause::eek:

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but even if he did let it idle for 15 mins 3 times and gave an easy break in , it still sounds like its burning alot of oil even from easy break in..

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Hard to tell with out being there to look at it. I know from past experience that if you over do the assembly lube, it will take a bit to burn off. Especially the true tacky as shi! assembly lube. If it runs fine and sounds normal I'd run it just to make sure its not just burning assembly lube. Just my .02

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well any time you get oil on the ring face and on the cylinder , you are done,

once oil finds its way buy the ring it wont stop,

this happens on any motor, its just worse on a slipper piston motor because you only have one ring,

i can't tell you how many of these i have had to repair for guys,

you will run that thing until you are blue in the face and never get the ring to bite into the cylinder.

it will always use oil and contaminate the combustion chamber, and it will hurt you ti valves and cost you power.

pull it all appart and kleen it all up, hone it real good, use new rings ( the edge is gone on you new rings and they wont work)

then wash everthing up in hot water and dawn dish soap, head valves ,piston,rings ,cylinder,

then brakeclean all the parts very dry, and make sure they stay dry and spotless.

then assemble and keep spraying brakeclean on everthing you touch including your fingers and assemble it all dry,

put a film of 30wt on the rod eye, and a film on the 4 valve stems,

almost none,

and keep re-cleaning the piston and your fingers,and assemble correctly and make sure the top ring is on with the mark up , and the ring end gaps are indexed in the cylinder correctly--then button it all up.

then kick the thing over with no oil in the motor 40 to 60 times slowly to help the ring bite , then fill your crankcase on the low side , warm it up stink hot and ride it like you stole it ,

now you will have a tight sealed combustion chamber and the thing will make good klean power and your ti valves will live and it will work like it was designed to !

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I thought white smoke was a sign of a coolant leak, like from a bad head gasket. Wouldn't the smoke be dark if it was burning oil?

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I thought white smoke was a sign of a coolant leak, like from a bad head gasket. Wouldn't the smoke be dark if it was burning oil?

That's what I was thinking...I thought white smoke is a coolant leak, blue smoke is oil burning, and black smoke is the engine running rich :eek::applause:

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#1 these newer oils we all are using now burns white.

#2 you know when you are burning antifreeze, you can't mistake that sweet burnt funny smell of coolent,

and generally on the bikes it pushes the liquid right out the pipe on the floor .

and there are so many of these out there because everbody still for whatever reason wants to oil the parts of the motor up that should never have oil on them, that you just know what it is , even over the computer.

this really started in the 60's when the oils are just to good to dare get it on the ring face,

old hot rod and dragster guys from the 50's were and still are doing a dry build,

do you know what you get when you get oil in a cylinder with a nitro top fuel car ???

you get a bomb,---it is for all practical perposes TNT----and they go boom.

when you see those things just grenade , thats what happened ,

trust me the dry build is the way to go on everthing,

oil dose not belong on or above the ring,

its real bad when you only have one ring that is doing the compression going up and the oil scrapping going down.

not to mention an oil control that is designed to be an oil floater ring designed to trap a land full of oil to make the piston float on the cylinder wall using crankcase pressure and oil forced in the underside holes from a sprayer to keep the land full and cool ,

so that one ring is doing triple work , and its a low tention ring to boot.

you get oil on it and it cant work,

actually the 2 strokes are the hardest to get sealed and to work correctly,

no there is a whole nother discussion that will consume hrs of time and very deep thought. :applause:

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FWIW, I used kelstr's above method on my 250F when I installed the JE piston...that thing does not burn a single drop of oil between changes and even the drain tube only gets condensation in it.... :applause: It gets ridden hard too. I am almost ready to install a new ring on the same piston to bring the power back up before another piston change.

Dark smoke is usually too much fuel....

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If the best way to break in a new top end is to assemble it "dry", why then does the instructions with the JE piston for the CRF clearly state do not assemble dry? Wouldn't a piston manufacture want to give proper assembly procedures in their instructions and if the best way to assemble the top end is dry, why wouldn't they state that?

And does Honda assemble their motors in the factory dry? If not, then why not if that's the "best" method?

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its just lawyer talk they half to provide to cya,

all the makers , car,truck, bike and part manufactures all still do this and have for the last 75 years,

because they know some idiot would run the thing dry at full throttle and get killed and it would be a slam dunk $10000,000000. easy winable law suit.

so they have to do this ,

and they don't want any privateer racer to get one up on them by really knowing how the real motor work is done for a tight sealed motor to get that extra little bit that they have,(among other things that would amaze you even more ).

and the factory's can't assemble dry, because shelf time of sitting and moistrue problems with rust,

thats why most guys with a 250 crfr and x burn oil and some 450's do also,

they try to use just alittle and they are now using "pale oil" witch gives you the best shot of drying up, but there are still many with burning oil and killing valves because of this engine dirt and blow-buy,

its just the way it is, -----and always will be,

if you want a killer sealed top end you will disassemble your new bike and do it the way a racer would do it,

not the way a manufacture would do it to sit on a boat ride somewhere !

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If the best way to break in a new top end is to assemble it "dry", why then does the instructions with the JE piston for the CRF clearly state do not assemble dry? Wouldn't a piston manufacture want to give proper assembly procedures in their instructions and if the best way to assemble the top end is dry, why wouldn't they state that?

And does Honda assemble their motors in the factory dry? If not, then why not if that's the "best" method?

Read kelstr's reply....if you want to oil it up, go for it. It will run, just not as good.

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dont worry , it wont run dry , you are not going to start it with out oil ,you are only going to kick it a bit with out oil , when you add the oil & start it every thing under the comp ring will be showered with oil :applause:

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Kelstr Post it, I promise I will read it.

I have built several two strokes in the last year. I built them dry as you told me to do. They perform much better, the pistons lasts longer, and the biles drool 100% less out of the exhaust pipe. I am a believer!

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i have been using a dry film lubricant tungsten disulfied burnished on the ring in the cylinder and piston skirt and just a spot of asembly lube on the skirt of the piston wich is probally more lubrication than it sees while running .

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