A few questions (overheating)

[2 strokes 4 life]

Bike: 2002 EC250

Mods: LTR jetting kit with 42 pilot jet air screw 1 and a half turns out

Backround Info My bike was running fine up until last night when i decided i was going to go on a ride. The trail was rooty and and lots of gravel up hiils. I reved the bike fairly high up those hills and bogged it on the roots befor that. Once i was at the top of the trail my bike was boilling big time. I lost half my anti-freeze. I decided to push my bike home just to be on the safe side. When i arrived i kicked the bike over and it started fine and ran well. I then thought it would be the plastic impuller that was the problem. I also noticed that my bike has been making very loud mechanical sounds when operated in the lower RPMs (not sure what this is).

Inspection: I saw my air filter was somewhat dirty (cleaned the ride befor this one), took out spark plug and it was a light brown almost white (sing of overheating?), took off the ignition cover and there was a table spoon or so of water, took of powervalve cover and there was lots of oil and black spoonge or carbon, took off water pump cover and nothing is wrong with the impuller, i have yet to drain the oil because i just replaced it the ride befor, lots of crap gathering near the powervalve drain off tube and on the tube it self, and thats about it i think.

Questions What is or could be my hot running issue, what might the lower RPM sound be, what should i clean the power vlave with, what should i clean the ignition with, and i think that is it.

Thanks for any help you can send my way.

 

[GMP]

A GasGas 2-stroke is inherently one of the most boil resistant bikes out there, the cooling system does an outstanding job even under extreme conditions providing the bike is jetted decent and there are no other issues. Some of the plastic impellers have been known to fail under extreme conditions but if its intact thats not the immediate problem. Also replace the cap with a 1.4 bar KTM cap (1.2 is stock and releases a little too easy). If your boiling over bad you have another problem.

Bike sounds lean. First, post your exact jetting/altitude/temp. If you have a newer LTR kit up to 1000' the needle should start in the middle position on a 250. Main should be around 178 pilot 42 -45. Plug should not be light tan, but a medium dark brown. Check for air leaks and correct float level.

As far as the sounds is it normal PV noise? A detonation knock? Simply the chain slapping the swingarm guide when the bike is lugged? This is a common point of alarm to many newer GG riders.

 

[SpeedyManiac]

I've noticed on long sandy climbs my bike heats up, but otherwise I haven't had boiling problems since I first got a GasGas in the C class. Sometimes a bike will overheat. Long uphills in a low gear and on the gas tend to heat things up. I've found the easiest way to avoid overheating is:

1) Avoid bouncing off the rev limiter all day.
2) Keep air moving through the radiators.


By the way, when's the last time you blew out your radiators? If they're plugged up or if a lot of fins are bent over the bike will run hot.

 

[2 strokes 4 life]

Altitude is about 2500FT, and temp is 15-25 deg Celcius. I think my fuel filter needs replacement because there is dirt in the float bowl. I think i will also use a 178 main jet. The PV seems to be fine because there is now play eaither way i move it.

 

[JoshP]

When was your last top end job? I had a similar issue on my bike and it turned out that one of the head gaskets had split and was letting coolant in
burning it all up. I would lose half my coolant every ride until I found the problem. Might not be your issue but something to look at especially if the bike has been running fine for a while and it's out of the blue.
2 cents - Josh

 

[2 strokes 4 life]

It has not been rebuilt. Its on its stock top end. I am going to tear it down and rebuild while i have it apart.

 

[JoshP]

When you do that rebuild check the condition of the inside gasket that is where mine had cracked and was letting the coolant in. Good luck with it.

 

[iancp5]

I often find moisture in the ignition cover but not water - might be worth checking if there's anti-freeze in that water or if it appears from a dry test ride assuming you've cleaned it out now. Does sound like a head gasket though.

 

[2 strokes 4 life]

Mt ignition cover gasket was not sealing. Thats why the water was there. Plus we ride lots of deep water and mud.