OK...my valves are doing ok so I am not worried there.

I am concerned about a bit of oil smoke. Here are the conditions it occurs under.

1) After first starting and letting idle for a minute or so...like when I am up on the line I let the engine idle long enough to get the radiator top warm to the touch.

2) When I give it some gas, it will blow a puff or two of blue smoke (you can smell it too) for the first couple of wicks, then no more.

3) It does not smoke under race conditions or any normal riding conditions, only in the above listed circumstances...


I think this is the normal smoke some ppl have complained about ever since the 2002 CRF hit the floors???...it does not USE any oil at least in the time period I change it in...and it runs super, I can still pull holeshots against anyone on any bike (that part is up to me LOL, the bike can handle it fine!)

The bike has about 40 hours of hard riding and is otherwise in tip top shape. Probably nothing to worry about but I am just fielding opinions.

Mine does exactly the same thing. It uses no oil at all. It also only happens on the first start-up from dead cold in the morning, never on a restart later in the day. I don't worry about it at all.

mine does the same thing. Uses no oil and only does it on the first start of the day. I have two friends with 450's that do the same thing

Randy

Thanks guys....I am not worried any longer....

A little smoke when first starting is normal. I think the biggest worry is keeping the valves in adjustment. I was wondering once you started having to adjust and shim, how long it was before you have to replace the valves?

Metal objects contract when cold and expand when heated. Your valves are set to specs so that they seal best at optimal operating temperatures (when your bike is warm). Since the sealing surfaces (the valves and their seats) are cool upon first start-up, your valves could be termed "loose" at this point and you get excess oil that blows by them coming out of your exhaust. As they warm-up to operating temperature, the metal expands and the seal tightens to the correct tolerances. No more excess oil gets by (now only exhausted fuel), no more excessive smoke.

i have had mine CRF since OCT of 01... never even checked the valves... starts 2-3 kicks cold or 1 hot.. its done the lil smoke thing since day 1 & i just consider it normal for the bike... no oil is used ever & i have many hare scrambles on it & weekly moto practice...

You lost me there, Maniac!

Rap

If its a Blue smoke........ it must by a Yamaha. The Honda will puff RED

I don't think its a problem.............

I said the same thing LOOPOUT, then 10 miles away from home in amongst the biggest bad a s s hills we have the engine wouldn't start after i stopped to drag it under a tree. I have an auto clutch so was NOT HAPPY.

I did make it home. after getting a tow from a 4x4

Turns out my valves just gave out.

REDOZ SHHHHHHHHHH dont jinx me...

Actually when my buddy gets back from Japan we are gonna do a inspection of the valves.... but i have no worries or concerns with the red meanie

Are you sure your valves just arent outta spec? They might not be "done" just need a re-shimming. Anyways, you guys arent alone, check out the 250f board. Some guys needing to replace valves there too.

I would like someone to explain to me how the valves beeing out of adjustment can cause the smoking that was described earlier. Buy adjusting the valves has absolutly nothing to do with the oil sealing part of the valves. I would be more apt to say that the oil is a little residual getting past the rings tell the bike warms up to operating temperature. Just my opinion though.

I agree with Tapkawiman, it seems like it would more likely be the rings... Since (and I'm no mechanic) the valve stem in the only thing that actually is in contact with oil (on a regular basis anyway), and the valve stem seals should maintain a seal regardless of temp. I honestly don't know if that would be the case, but it seems more logical to me.

My 02 has done this from day 1. It will puff out smoke if you hammer it after the first start of the day, if you let it warm up for a couple of minutes before twisting the throttle it will not do it. I was informed by our Honda tech rep that it is blow by on the rings until they and the cylinder reach operating tempature. Just let these things warm up before you open them up, its not a 2 smoke that needs to be cleaned out when fired up. My 2c.

rapture, just wondering how your motor was broken in. did you putt around forever like the manual says or go for broke from day one, just curious. there seems to be a ton of different ideas on how to brek in a four stroke. i have a brand new 250F and am still not sure how to break her in. some guys say fast and hard, others slow and gentle.

I may be totally wrong on this but I dont think that the smoke that your seeing is from oil. Every CRF that I've seen does it, every time you gas it a puff of smoke comes out the exhaust. I think that it is because of the pumper carb, while your giving it more throttle it squirts in extra fuel makeing the engine run rich for a split second and spitting out a puff of smoke. I've heard of people (mainly Yamaha riders) cutting back the amount of fuel that is added and have actually noticed an increase in fuel mileage and better throttle response. Just my 2 cents.

I think if that was the case it would only get worse as it warmed up. Mine does it, my 02 didn't. Both bikes were broken in the same way. Definitely blue oil smoke...

YES....mine is blue oil smoke. I have been in the automotive business for a total of 10 years plus 4 in motorcycles and I know what oil smoke smells like as well

I broke mine in "semi-hard" as in half to 3/4 throttle, no lugging and no redlining, for a total of 45 minutes.

The smoke has seemingly only started recently, but to be honest, I wasn't looking that much before.

Mine will give the puff of blue smoke after startup, even if I let it idle for 2-3 minutes, which as we all know is completely warmed up on these bikes. But it only puffs on the first and maybe the second twist, after that, it is gone...but it is running strong, getting me holeshots and wins, so I can't really complain. Not to mention it is NOT using oil...

Oh well, I will prob slap a piston in it before the summer riding season, these things are cheap to rebuild...I priced the parts out at only $107.00 from Service Honda...

Hey just another thought. I just relized my oil breather tube was filling up. It needs to be drained often. It's connected to the air box also and may cause the blue smoke at first if to much is going into the intake. Just handn't heard anyone with that angle yet. There is a plug that can be removed to drain the oil in the clear tube. May be good to just leave it off and bypass the breather in the carb.