gilera runner cooling system

jacky230766 · L Plate Warrior Joined: 11 Sep 2011 Karma :

hi all,
after starting my bike to test new headlight i noticed a burning smell,turned bike off and found a very hot head ,i think the coolant system isnt working properly,hoses were all cold to the touch as was rad but piston head and barrel were hot to the touch, (piston head and barrel have been changed and i've done about 12 miles on it since with no probs,could there be an air blockage if so how do i bleed the system,or could it be the water pump or poss thermostat (cooling system was drained,and bleed for replacement of barrel) checked for leaks and can find none,
any help would be greatly received.
bike is gilera runner 03 plate

orac · World Chat Champion Joined: 25 Sep 2011 Karma :

2 or 4 stroke runner, i am pretty sure the 2 strokes have a bleed valve some where on the top of the head. i can check tmrw after noon.

but i would be inclined to check the thermostat. if needs be see if it happen with no thermostat - this will force the the thing to cool even when its cold

jacky230766 · L Plate Warrior Joined: 11 Sep 2011 Karma :

sorry its a 2 stroke ,was wondering if thermostat had been put back right (seems to look it) i know where bleed nipple is just dont know how to do it,only ever had air cooled before

orac · World Chat Champion Joined: 25 Sep 2011 Karma :

crack it open, if nothing come out, tunr the engine over (by hand if possible). dont let it get hot while the nipple is open, when fluid run out close it up and see what happens.

you may like to attatch a pipe so you dont get coolant all over the engine

jacky230766 · L Plate Warrior Joined: 11 Sep 2011 Karma :

thanks will try and see what happens,

orac · World Chat Champion Joined: 25 Sep 2011 Karma :

right OK this is basically what the haynes manual says.

"remove engine cover. fully loosen the bleed screw and attach one end of a suitable length of rubber tube to it. place the other end into the coolant reservoir.

fill the system all the way to the MAX level line of the reservoir with the proper coolant mixture, (warning about doing it slow...). as you fill the reservoir, air will bubble up from the tube you have attached to the bleed screw.

when the system is full and no more air is comung out of the tube, tighten the bleed screw and instal the reserboir cap.

start the engine and allow to idle for 2 to 3 minuites. flick the throttle twst grip part open 3 or times, so that the engine speed rises, then stop the engine. loosen the bleed screw to allow any trapped air to escape (do this on the main stand), then tighten the bleed screw agaim.

allow to cool, check level in res, rinse and repeat if need be