Smoke When First Start-Up

[Matt400ex_17]

After now that i have everything on my bike when i first start it up it blows a lil smoke kinda gray black not blue. Is this normal my 400 never did this. Once it's warm though its fine only the first start of the day. It' s jetted fine plug looks good so what could it be ???

its nor normal..mine doesnt smoke & neither do any other crf450's ive seen when starting up...sounds like piston rings maybe? :confused:

[turboTony]

blue smoke: oil
white smoke: water or coolant
black smoke: fuel

[WhiteZee]

you may want to clean your air filter, a dirty one could cause this problem.

Matt

My bike does the same thing. It's an 05 with only 2 tanks of gas ran through it. I don't think this happened until i put the hmf exhaust on. I'm wondering if it is just condensation in the pipe. And the "straight thru" design of the hmf makes the smoke more visible? My smoke is more of a white to light gray.......and it's thin. The fact that it is thin, makes it kind of hard to determine what color it is. My bike seems to do it after i start it up, then give it the first big rev. After that, it doesn't do it anymore.


If anyone has any info to add, let us know. Because, i'm a little concerned also.

[bcurry940]

Mine does this also on a cold start up. But only after it has sat in the garage for at least 3 days without being rode. It smokes on start up for maybe 1 minute then everything goes to normal. Better not be rings or anything serious my warranty just ran out last week!

[Jersey450R]

mine does the same thing, it could be left over water in there from washing. my 300 and my 400 did the same thing, right after i started it and gave it a few revs.

[4StrokinJay]

If it were the rings it would smoke all the time...valve seals if it only does at start...but it would be smoke not like a steam.

[Matt400ex_17]

it is only after it sits a couple days but then i started it tonight and nothing so i dont know. Hope like heck not piston at most 60 hours on it.

[Martin Blair]

mine does this after washing or really hot and i put it up, i put my hand behind my pipe and figured out is was just steam from condisation, just feel the smoke that will tell you.

[Martin Blair]

mine does this after washing or really hot and i put it up, i put my hand behind my pipe and figured out is was just steam from condisation, just feel the smoke that will tell you.

Originally posted by Matt400ex_17
it is only after it sits a couple days but then i started it tonight and nothing so i dont know. Hope like heck not piston at most 60 hours on it.

i'll be taking mine to the honda shop very soon for a check up. i'll try to get to the bottom of this then. Mine is diffenately blue smoke from burning oil. I've talked to a few people who know a little about 4-stroke engines, and they say it may "trapping" or "leaving" a small amount of oil near the valves at shut off. Then, when you start it later, and get on it, the valves suck that oil in, and burn it.

I'm not sure. I haven't dealt with 4-strokes much in the past. I've always been a 2-stroke man... that is.....until I laid my eyes on the 450r. hahaha

[remlapr]

Mine does this when I first start it after it's been sitting. Just a small amount and only for the first couple of throttle blips usually. It does almost seem like steam or really just heavy exhaust more then actual smoke because it's gone about 2ft past the pipe. I'm not going to sweat it unless it starts doing it all the time or get's worse on start up...

I spoke with my honda dealer. He said it's nothing to worry about. He says it should quit after the bike is fully "broken in". I'm not an engine whiz, so i can't give a technical description. But, he said the engine may be leaving some residual (sp) oil after shut down. And, this small amount of oil gets pulled thru the valves and burnt. Like i said, i don't know enough to give an accurate description. But, what he said seemed believable.

I'm taking mine in on 10/2. Maybe i'll learn more then.

[gemfride]

I have an 04 and an 05 450R in my garage and both of them do it since their birthday(HAHAHA The day that me and my buddy bought them.) I agree with a few of the earlier posts but I do know a little about motors. I can definetely tell that my smoke is black, which in return means, too rich. It only does it on start up. I also do know that people say you shouldnt leave your fuel on on a 2 stroke. In my opinion and with my personal tests I can turn my fuel off run the bowl dry. Then when I get ready to ride. Turn the fuel on choke it just for a second (enough to start) then cut the choke off. This little method seems to work for me. It is kinda like the floats are sticking or the carbs are a little off from the factory. I think its funny though cause when we ride and meet here at my house everyone laughs becauser of the smoke, but after we get warmed up and I smoke their azzz, I am the one laughing.Cant you tell that " I love my 450R!!!!!!!!!!!


The only way to ride is team red .

[jeepnrocks]

Originally posted by gemfride
I have an 04 and an 05 450R in my garage and both of them do it since their birthday(HAHAHA The day that me and my buddy bought them.) I agree with a few of the earlier posts but I do know a little about motors. I can definetely tell that my smoke is black, which in return means, too rich. It only does it on start up. I also do know that people say you shouldnt leave your fuel on on a 2 stroke. In my opinion and with my personal tests I can turn my fuel off run the bowl dry. Then when I get ready to ride. Turn the fuel on choke it just for a second (enough to start) then cut the choke off. T
if you run it dry arent you leaning it out ?

Originally posted by jeepnrocks
if you run it dry arent you leaning it out ? i hope not b/c I turn my fuel off & let it idle till it dies everytime I get finished riding for the day.

[jeepnrocks]

hey mike, i dont have a fraction of the knowledge that some of the other guys on here have but it seems like if you kill the fuel then its going to get less and less fuel but still the same ammount of air which will result in leaning it out pretty bad by the time it actually shuts off.
might be nothing to worry about but might be worth making a separate thread so some of the experts here coulod give ya better advice. better safe than sorry

Originally posted by jeepnrocks
hey mike, i dont have a fraction of the knowledge that some of the other guys on here have but it seems like if you kill the fuel then its going to get less and less fuel but still the same ammount of air which will result in leaning it out pretty bad by the time it actually shuts off.
might be nothing to worry about but might be worth making a separate thread so some of the experts here coulod give ya better advice. better safe than sorry yah...im just not gonna do it anymore...ill just turn my fuel off now when I get done riding

[gemfride]

Well another opinion of mine would be that for one it does not have a fuel injection system, and it is not a 2 stroke. I never said that I was an expert, but I thought that the reason for forums was to trade suggestions and opinions. Oh well I guess that opinions are like *******s everybodys got one. Even if you run the bowl dry it is still getting the same amount of fuel and air til it runs out. I will keep doing mine like this, you dont have to do yours, but its just my opinion. Another thing, wouldnt it mess your motor up by using your choke. I mean it does "RICHEN" the fuel. LOL:devil:

[jeepnrocks]

Originally posted by gemfride
Well another opinion of mine would be that for one it does not have a fuel injection system, and it is not a 2 stroke. I never said that I was an expert, but I thought that the reason for forums was to trade suggestions and opinions. Oh well I guess that opinions are like *******s everybodys got one. Even if you run the bowl dry it is still getting the same amount of fuel and air til it runs out. I will keep doing mine like this, you dont have to do yours, but its just my opinion. Another thing, wouldnt it mess your motor up by using your choke. I mean it does "RICHEN" the fuel. LOL:devil:
dang u sound angry !! if u run the quad dry its going to try to get fuel as long as p[ossible. it wont die all at once.
also i am fairly sure that the biggest danger of running a little rich is maybe a fouled plug

[turboTony]

Rich is a LOT safer than lean!
I have a turbo DSM and when setting my fuel system up, I basically set it rich as hell and then lean it out till it knocks (very lean) and then add 10% more fuel from where it was when I first saw signs of knock. Thats a pretty sweet spot thats safe but still making lots of power.
Now the reason "lean" is bad is because a lean burn will cause lots of heat which in turn will cause detonation and then knock. (unfortunatly thats when you also make the most power! :devil:
For a lean condition to do any actual damage, you'd have to be running it at high rpm, under load.
Merely letting it idle to burn whatever's in the bowl takes just a minute or two and not being under any kind of load is not anything to worry about....

[gemfride]

For a lean condition to do any actual damage, you'd have to be running it at high rpm, under load.
Merely letting it idle to burn whatever's in the bowl takes just a minute or two and not being under any kind of load is not anything to worry about...


Thanks Tony!! The choke thing was a joke!!!