Bike seems to leak coolant from kickstand ??

[mbmO8]

I’ve tried another cap ( an old one that came with the bike as the bike came with 2 boxes of parts) and it seams to be worse so I think that shows both caps are bad and the og one wasn’t as bad

Thank you very much

[mbmO8]

Hi again, so after trying a new cap it hasn’t seamed to fix it but I am 95% sure I found the source of the leak (see image ) is this hole ment to be used as an overflow and does anyone have a full Coolant system diagram

[mbmO8]

Update.

so i have a reason to believe that its my water pump that has failed, does anyone know how to test the water pump before removing it ?

[Calum]

Why would it be the waterpump? That's on the other side of the engine/bike. It's no where near the stand?

Do you mean you think it's getting hot and overflowing because the waterpump doesn't work???

[mbmO8]

Been working on it all day and we have since found it wasn’t the water pump still trying to figure it out haha

[SpookDog]

Have you checked the thermostat?
Is the coolant in the radiator staying at the same level, or are you constantly topping it up?
The only reason for the expansion tank to be full and overflowing is if the head gasket has blown and is pressuring the coolant system, which results in loss of coolant through the expansion tank.

P.S. yes the expansion tank is connected to that part of the frame by a small rubber tube. it lives up behind the side panel above the rear wheel. there's a min & max level about halfway up the tank. Check it out to see if it's full to the top...

[mbmO8]

@SpookDog would this not contaminate the coolant as I have never seen anything in the coolant and always drains perfectly clear

[SpookDog]

@mbmO8
Sorry for late reply.

It’s since you did the top end build I’m thinking about, not before.
It can take a while for sludge to build up.

Is it loosing coolant from the radiator? Check the level …

[mbmO8]

Yes it’s loosing cooling from the radiator quite a bit

[SpookDog]

@mbmO8

Head’s still leaking bud. It’s probably best to replace the base/barrel gasket as well.
Myself, I remove the studs from the barrel an lap the top in with a square of plate glass and some 240-ish wet and dry sand paper. Then do the same with the cylinder head. Just to remove the crap.
Doing up the head nuts really needs a little 1/4 in drive torque wrench to get it right. I do it in three stages…

I know that it’s no consolation but I’ve just had to put a newly rebored barrel and head on and had to go through all the fuxin hassle of it myself 🫤 …