rich or lean?

[polabareus]

Ok, have a new 250ex. The header glows red at least at idle and I haven't looked to see if it does on mid throttle or wide open yet. Anyway, the dealer said these bikes do that and that its because its running rich. I don't know much about this kind of stuff but after reading several posts here it seems a glowing header would mean its running lean. So is the dealer right? If its normal fine, but I don't want to slowly be wrecking my engine and have it break down in the future. by the way all stock, no mods.
thanks,

[sweet300ex]

yes, it means its running lean

[trailburner]

It's running lean.....& no it's not normal...if it's new & has a warranty on it the dealer prob just doesn't want to fix it..I would get it fixed ASAP!!it's not good to run a motor "lean/hot"

[polabareus]

I have also noticed when I deccelerate from 4th or usually 5th gear that it lets out a few faint pops. If it is running lean is there something on the carb I can adjust. I wouldn't think I would need new needles because Ive made no modifications so im thinking it wasn't set right in the factory. Basically how do I adjust the mixture. And how do I know its set right if I do?

[hondarider2006]

your air-mixture screw is your idle setting, so you will want to go out on that to richen it up a little. Not sure how many turns it is out already though, look in your manual, it may tell you, if not ask your dealer....or another fellow exrider:)

[cals400ex]

yep, richen up the fuel skrew on the bottom of the carb. i assume its a fuel skrew, so i guess you would turn it out to richen it. i would do it in 1/4 to 1/2 turn increments.

[2004TRX450R]

It is normal for them to do that. It doesn't mean it is running lean. The poping on decell is an indiator if a lean condition though. After the bike it completely warmed up turn the pilot screw in or out to the position that it idles the highest. It is very common for the pipes to glow at idle because there is no air moveing across them and they are single walled pipe. Every YZF 250, 426, 450 and TRX400EX or CRF that I have seen will do that at idle.

[hondarider2006]

Originally posted by 2004TRX450R
After the bike it completely warmed up turn the pilot screw in or out to the position that it idles the highest.


doing that may burn a little.....you might want to do it while the bike is cold.

[2004TRX450R]

There are specal tools for getting in there but I have done it with just a small screw driver. You can't do it when it is cold because it will run different when it is cold. If you set it up cold it will be way to rich. To do it correctly you have to do it at operateing temperature.

[MDE3]

Suggestion: If you are not running in a particular extreme of climate or altitude, the facti=ory seetings for these bikes are pretty standard, and it would be unlikely although not impossible to to have the wrong jet settings on a new quad.

Did this situation develop or was it there from the moment you got the quad?

You might also check that your exhaust header studs are tight and you have a good exhaust connection to make sure you do not have an exhaust air leak. This will also cause the quad to backfire, appear to run lean, and cause your pipe to heat up due to excessive detonation inside the pipe..

Have you looked at your plug? That will tell you right away if you are running rich or lean.

[2004TRX450R]

It is hard to tell from the plug if it has been run for awhile. You need to put a new plug in and see how it looks after you run it for a bit to get an accurate reading. I will agree that it is unlikely to be off on a new bike that hasn't had any mods done on it.

[cals400ex]

Originally posted by MDE3
Suggestion: If you are not running in a particular extreme of climate or altitude, the facti=ory seetings for these bikes are pretty standard, and it would be unlikely although not impossible to to have the wrong jet settings on a new quad.

Did this situation develop or was it there from the moment you got the quad?

You might also check that your exhaust header studs are tight and you have a good exhaust connection to make sure you do not have an exhaust air leak. This will also cause the quad to backfire, appear to run lean, and cause your pipe to heat up due to excessive detonation inside the pipe..

Have you looked at your plug? That will tell you right away if you are running rich or lean.

we need to remember, temperature and jetting will play a big role in jetting. you WON'T use the same jetting in the summer as you do in the winter, even if it is a stock bike. well, you can, but you won't get the most performance. let me guess, its starting to turn red and also the temp is dropping??? also, i actually get the best results by checking the plug with the old one in even though everyone says put a new one in. when i put a new one in, it takes too long to get a good reading. over time, we all get our own techniques that they prefer. try this, get the bike out and ride it until it is up to peak temp. stop the bike and let it idle for a minute or two, but not too long since it is an aircooled bike. shut it off and check the plug. take note on the color. put the plug back in and take the bike out and run it at 1/2 throttle through all of the gears for a good distance. shut it off as you are going and check the plug. take note on the color. at idle, your pilotjet/fuel skrew is being used. at 1/2 throttle, your needle is being used. a glowing header is not necessarily suppose to happen. yes, it can occur without any damage. however, when the header starts to glow, that is the indication to me that i am running lean and i need to richen up one of the jets.

[MDE3]

As my experience is mostly limited to pure race motors with Lectron carbs(no adjustable idle jet, just a tapered flat on the primary needle which serves as the low rpm needle/jet) which were set up for no idle, I never had a problem determining lean or rich from 5-10 minutes of running time at race conditions (hard acceleration and high rpm/s). The plug would be either white, tan or approaching black. So I agree with what you propose as a procedure for stock carbs, given the differences in design and purpose.

And yes weather is an important factor, but that is why I was asking if there were any extremes of climate or altitude, and whether this problem started right away or developed over time.

I did have the problem of exhaust leaks when I changed pipes on two different machines, which caused the same symptoms however.