On my R1 there is a small breather pipe just above the water pump inlet (beneath the prop).

- Can this be blocked off?

Thanks

James


(p.s. its a carbed R1 engine - 2000)

No, its there to prevent airlocks in the pump. I plumbed it back into one of the breather outlets on the header tank.

Nick

I've connected the bottom of my header tank to this. Any water loss from the system is replaced by a constant feed from the header. The breather from the thermostat goes to the top of the header so any air in the engine generally gets swapped with water from the tank.

At the moment I have the bottom of my header tank going to the bottom pipe between the radiator and engine.

The top outlet from the header tank goes to the radiator breather.

Effectively is this not very similar to yours Smart51? As I have a pipe at the top of the system going to the top of the header tank, and a pipe at the bottom of the system going to the bottom of the header tank?

Also, does the header tank have to be completely sealed? I.e. does there need to be a pressure cap on it or just a normal screw top?

James

I have the bottom of my header plumbed into the cold return which is the lowest pipe in the system. I have two top outlets, one plumbed into the thermostat breather, the other plumbed into the pump breather that you described.

Nick