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Warm up smoke

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I thought I would post this question here figuring the most detailed answer I'm looking for would come. I have a 2006 CRF450R, bone stock engine W/ approx. 20-25 hrs. Every time I start it up when its cold I use the choke and let it idle for about 30 secs. W/ the choke on, I then turn the choke off and give it throttle to keep it revved at same speed as if the choke is on for about another 2 minutes then begin to rev it slowly increasing rpm until the cylinder is HOT to the touch. Now the first few revs I make slowly it always blows a few "puffs" of smoke. Just "puffs", not clouds. What is this? Should I be worried? In addition, I do not bounce the engine off the rev limiter but once or twice ever tank of gas and I dont race this engine. What signs do I need to look for if the engine is approaching the end of its service cycle? cause I really dont know.....I just have a good idea. I want to actually know. Thanks.

p.s. and another thing....Ill look back when I'm riding and nail the throttle and I'l see a slight "puff" of smoke come out, this normal? I've never really paid any mind to it but now im starting to.

Edited by CRF450ish
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A small amount of light smoke at start-up isn't unusual, and probably isn't a cause for concern. The smoke while riding is, however. It would seem to indicate to me that either the rings are worn and allowing oil into the combustion chamber during off-throttle (when there is no combustion pressure to force the rings against the cylinder), or the piston is beginning to rock in the bore and not keeping the rings square.

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Im with grayracer on this one. Mine did the same thing, one of the valve guide seals was split.

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nevermind......i could do that in like 15 minutes. as a matter of fact my buddy has some for his bike.....07 CRF450. just looked in my manual. thanks.

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nevermind......i could do that in like 15 minutes.

Do a video. If you can get the valve springs off, replace the seals, get the springs back on, and close up in under an hour with the head on the bike, I'd like to watch. :banana:

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Do a video. If you can get the valve springs off, replace the seals, get the springs back on, and close up in under an hour with the head on the bike, I'd like to watch. :banana:

+1 :lol:

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what the hell? i havent even raced it. how hard are they to replace?

i really do hate when people throw that into the mix as a reason...the motor doesnt disquinish between racing and not racing... its all in the rider and how they maintain the bike...

ive seen plenty of "non-racers" just constantly hitting rev limiters, which is a nono, not maintaining their bike worth a crap. and ive seen "racers" just ride it in the race like they were riding for shits and giggles of it but take very well care of it to the point where it still looks showroom good

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