Radiator Overflow

[geraldh]

HELP - Coolent seems to pump out of the Radiator Overflow when I kick or start the bike - Coolent is still cold I have changed the O-rings between the Head and Barrel , could it be the Radiator Cap, The bike is a 2006 ec 300.

Any Ideas would be helpfull.

G

[GMP]

Yes it could, but it would have to be stuck wide open to loose coolant from just kicking the bike.

Did this happen after a rebuild reassembly? The head o-rings are new, are the grooves in the cyl and head surface in good shape? Not pinched on install? Remove the cap and look for bubbles, thats a classic sign of a compression leak into the system.

Less likely but possible is your base gasket, as it seals the coolant passage through the cylinder from crankcase pressure. It would also tend to draw coolant in when the case is under a partial vacuum. Open the crankcase drain bolt, if you see evidence of coolant that could be it.

[geraldh]

Originally Posted by GMP

Yes it could, but it would have to be stuck wide open to loose coolant from just kicking the bike.

Did this happen after a rebuild reassembly? The head o-rings are new, are the grooves in the cyl and head surface in good shape? Not pinched on install? Remove the cap and look for bubbles, thats a classic sign of a compression leak into the system. I have only just got the bike so don't know mutch about its history, it was doing this when I bought it, I replaced the head o-rings the old ones looked Ok, it was a little tricky getting the new ones to stay in the grooves - I put a little air filter oil on them to get them to stick in the groove while I lowered the head back on, - how would you know if they came unseated after lowering the head back on? the head seemed to be level when I tightened it back up.

Less likely but possible is your base gasket, as it seals the coolant passage through the cylinder from crankcase pressure. It would also tend to draw coolant in when the case is under a partial vacuum. Open the crankcase drain bolt, if you see evidence of coolant that could be it
.

-I have tryed a 1.4 bar radiator cap and don't seem to loose coolant, if it was the base gasket would I still not "loose" coolant into the crank case? - I will check this in the morning though.

Thanks for the advice

[gasgasman]

You could remove the radiator cap and look into the radiator while you kick the bike over.
Should not have any bubbles.

Sometimes the head O-rings can pop out of place right when you set the head down on the cylinder.

[GMP]

The base gasket is unlikely, and the bike would run poorly. Whats odd is you say it pukes cold coolant, that can only be pressure from the engine. Remove the cap and start the bike, if its the head you will see bubbles, and the coolant will have traces of oil.

If its good with a new 1.4 bar cap your fine, 1.4 isn't going to cure a bad head seal.

For head o-rings, everything starts real clean. A light coat of grease while stretching them slightly, lay them in the grooves, and run your finger over the top around the entire o-ring several times until it seats and stays in the groove. Now, slowly drop the head on, and rotate it several degrees back and forth with a slight pressure before lining it up with the cyl. The motion should feel very smooth and even, if an o-ring was out of a groove you would feel it.

[geraldh]

My Bad .... when I replaced the iner 0-ring it must have poped out because when I removed the head again yesterday it had been pinched. I replaced it and all seems Ok - being a newby to 2 strokes I didn't relise that you can give the o-rings a good strech, Friday night I downloaded a you-tube clip where a guy showed how to do the rings on a gas gas triles bike, he showed how to strech them, all seems god now had an awsome ride yesterday.