What is this sound?
 

Is that sound just the power valve operating? Everything sound normal? I overheated my brand new bike and now I?m feeling paranoid. I?m talking about that rapid ?fluttering? sound

http://www.youtube.com/watch?v=CPPFHhsWPgY

http://www.youtube.com/watch?v=PD0di56sFTI


http://www.youtube.com/watch?v=fSmlNXX21xo

It's the sound of a bike idling..

I can hear a slight piston rattle in the background. But a lot of bikes make that noise especially when cold. Can you describe how and what happened when it over heated?

With about 6 hours on the bike I rode through a recent forest fire. The trail disappeared and basically had to cut our own through a foot of ash that had gotten rained on. I was in first for basically a 3 mile steady climb through this stuff. Towards the top I noticed steam coming off my header pipe from where the radiator over flow tube was draining and hitting it. This went on for about 10 minutes before I was able to stop and let it cool down. I ended up losing a couple ounces of coolant when I checked the next day.
Here is another thread I made with some pics of the cylinder head and spark plug. Not sure if anything in there would indicate damage from overheating, again I dont have a ton of experience so not sure exactly what I?m looking for.

http://www.gasgasrider.org/forum/showthread.php?t=23926

With about 6 hours on the bike I rode through a recent forest fire. The trail disappeared and basically had to cut our own through a foot of ash that had gotten rained on. I was in first for basically a 3 mile steady climb through this stuff. Towards the top I noticed steam coming off my header pipe from where the radiator over flow tube was draining and hitting it. This went on for about 10 minutes before I was able to stop and let it cool down. I ended up losing a couple ounces of coolant when I checked the next day.
Here is another thread I made with some pics of the cylinder head and spark plug. Not sure if anything in there would indicate damage from overheating, again I dont have a ton of experience so not sure exactly what I?m looking for.

http://www.gasgasrider.org/forum/showthread.php?t=23926

What was the coolant level before the ride? If it was filled to just below the neck of the radiator filler opening, it's very likely to burp coolant when it gets hot.

The usual coolant level is maybe 5-6mm above the fins. Adding four ounces is not uncommon, but still more than normal after a burp. The best way to judge overheating is to look at the head orings. If they are squared up, then the engine has been very hot, hot enough to affect the rubber.

If the orings are stiff they have been royally baked and you need to inspect the piston for wear. It's also possible to have the rings sticking after an overheating scenario.

Your pictures don't show anything alarming. The plug looks typical with stock jetting which is on the rich side. The buildup on the electrode is a bit strange, but I've had my plug covered in black carbon after four years on the same plug.

I agree these bike burp coolant when they get hot especially if they are filled above the top of the radiator tubes. I would ride it and have fun!

That rattle is the clutch. Pull in the lever when its idling and it goes away. Or put it in gear.

^1

Agree 100%!

Yep, I agree too... my sounds terrible at idle, then I pull the clutch in and all is well in the world again! :)

Also, if I fill my radiators up to the top then I lose a bit of coolant the first time I get the engine up to temperature, then all is OK.

Hey, by the way, from the photo I see the 2 stroke is leading the two 4 strokes, of course! If there's no smoke, there's no poke! :D