Problems with cooling System

[dreamon85]

hi guys, i write from italy. I have problems with cooling system since i changed engine on my bike. the problem is that i get the reservoir tank to be full with air and coolant, i think this problem is caused by bad linking of the reservoir tank to the cooling system. My bike is from 1992 and my new engine is from 1996..i spotted that this new engine has a hole on the head where passes the coolant..and on the old engine this hole was closed, like you can see in this photo

..now i linked this hole to the top of the reservoir tank, and the bottom of the reservoir tank goes to the top of the radiator nearby the cap..but this configuration does not work. I thinked to close that hole on the head and link only the bottom of the reservoir tank to the radiator..is that the correct way to solve the problem?

thank you and sorry for my english!

[Davw]

The hole that you have circled is for the supply to carburettor de-icing (standard for UK engines but not (I think) for Euro engines. If the carbs dont have de-icing then this hole should be blanked and not connected to anything. Try blanking it and that will solve the problem

[RedexRobB]

Exactly what Davw says.

Also note that the pipe from the radiator cap connects to the bottom of the reservoir tank, and the pipe at the top of the reservoir tank is tucked behind it and left loose as it is an overflow pipe

There are also markings on the back/side (depends where you look at it) of the reservoir tank that tells you where the coolant level should be.

[dreamon85]

so..if i got it well..the pipe on the top of the reservoir tank should be leaved free, not connected to anythuing, am i right?
@daww: I don't think carburettor have de-icing because mi first engine had that hole closed.

I have another question: when exactly the radiator cap opens to let the coolant pass from the reservoir tank? Is that due to the pressure or the heating?

Thank you guys!

[Davw]

1) The rubber hose from the top of the reservoir tank should be left as an overflow ( I tuck mine in between the tank and the engine)

2) The hose from the base of the reservoir tank goes to the connection at the filler cap of the radiator

3) The radiator cap has a rubber insert which will allow water to pass to the overflow tank under pressure (not temperature)

[dreamon85]

great...you are the men!Is quite a year that i'm trying to suolve this problems..i asked many people, but no one ever told me the solution!!!So i guess that my engine comes from england..