Brand new motor, red hot header.....

[DieselJoe]

Okay so i know a lot of you will say this is normal, but i am a little scared just because its a new motor, we started it up and let it run for like 1 minute, maybe slightly longer, and the header was RED and smoking..... and not like faint glow it was like as bright as the sun and we were in a very bright shop, carb is 2 turns out right now...... Any ideas? Im gonna try and richen it up and start it again and see what happens

[rdefonce]

Okay so i know a lot of you will say this is normal, but i am a little scared just because its a new motor, we started it up and let it run for like 1 minute, maybe slightly longer, and the header was RED and smoking..... and not like faint glow it was like as bright as the sun and we were in a very bright shop, carb is 2 turns out right now...... Any ideas? Im gonna try and richen it up and start it again and see what happens

sounds lean, yes you should probably richen it up . . . of course the jetting your bike was using during a warm up is low-speed jetting . . . pilot jet mainly.

So, it still might be jetted correctly for more wide-open throttle, but to be safe, besides a richer pilot you could raise the needle one clip position for more fuel flow.

[Bturner]

The bike isn't made to just sit & idle, it's made to be ridden. It needs air flowing through the radiator, etc. They love flowing air!! No need to adjust anything, just ride the bike, it'll be just fine!! My bike is jetted perfect & will do it if I start it up & let it sit.

[DieselJoe]

Arnt 4 strokes suppose to be warmed up for like 5 minutes before riding?

[crf450319]

Don't worry about it... you'll find out if you're too lean on the bottom end if you get a lot of popping on deceleration (closed throttle). We run into that when we're riding in early Spring and late Fall with the cooler temps, going up one size on the pilot jet fixes it.

 

If your bike isn't popping excessively, you're just fine..

[writebrian]

Arnt 4 strokes suppose to be warmed up for like 5 minutes before riding?

 

 

Uh, no! Warm it for 2 minutes max and ride easy for the first 5 minutes on the track or trail. They HATE to sit. They will begin to smoke and spew long before 5 minutes. 

[THUMPERRIDER1]

You should ride it and get a few heat cycles. If you have to run it in the shop then run a shop fan in front of the radiators.

[grayracer513]

Arnt 4 strokes suppose to be warmed up for like 5 minutes before riding?

 

Before riding hard, yes, but not at a standstill.  Most of them won't tolerate sitting still that long without boiling.  The warmup should be done underway.

[NitrousR1]

By chance What kind of header are you running? Did you just put this header on? most aftermarket headers glow significantly more then a stock header. Especially the fmf power bomb and megabomb.

[250premixer]

Okay so i know a lot of you will say this is normal, but i am a little scared just because its a new motor, we started it up and let it run for like 1 minute, maybe slightly longer, and the header was RED and smoking..... and not like faint glow it was like as bright as the sun and we were in a very bright shop, carb is 2 turns out right now...... Any ideas? Im gonna try and richen it up and start it again and see what happens

mine does that dw

[Rich1340]

I had the same problem with mine after the new top end. I bought the thumb mixture screw. Best $20 I've spent in a while. Backed it out 3/4 turn and solved the problem right away. It doesn't glow anymore.

[Mtrain730]

That does seem a little excessive. I stopped warming my 2012 up standing still.i let it run for maybe 30 seconds and then ride easy for a few minutes. But my header wouldn't glow after 2 minutes. I don't think think your crazy for looking into it. I have 24 hours on bike and have never boiled over and race And trail ride. I'm pretty confident I could let my bike run for 5 min from a cold start. Though I think it's totally uncalled for.

[slothman]

it's normal.  just don't let the bike stand still for 5 minutes lol.  warm up should be 2 minutes ...