Bike seems to leak coolant from kickstand ??

[mbmO8]

Hi all, I recently rebuilt my top end so had to replace coolant

After doing so it seams to me that the bike will leak coolant from the kickstand when I park it up and will begin to over heat when riding it afterwards.

Sorry if this is a dumb mistake but I can’t seem to pin point it thanks all

[Calum]

The kickstand, or are you talking about the coolant overflow pipes that should be routed through the holders next to the shock absorber to the flow.

This is usually an indication of head gasket failure.

When you rebuilt the top end, did you skim the head like I describe: https://dt125r.co.uk/topic/11/how-to-i-gentle-skim-your-head-barrel

Did you ensure to use genuine/Athena head gasket?

Do not use those cheap white head gaskets they don't work.

Also did you fit the gasket the right way around.

If you stick your fingers into the top of the radiator, are your fingers black/oily?

[mbmO8]

I will check over flow but I got an Athena head gasket for the bike and had the head skimmed too

And what do you mean right way round for the head gasket is there a top and bottom? We got it facing the right direction but if there’s a top and bottom I’m not sure

P.s. the coolant doesn’t look contaminated at all

[Calum]

Okay, good, using a good gasket set and the head/skim means it's unlikely to be that.

But yes, the headgasket only goes on one way.

You should be able to read UP on the gasket as it's installed. Otherwise you've installed it upside down.

Let's assume you haven't done that and it's all installed correctly, then I'd still be looking at the overflow bottle. It's possible that your radiator cap is shot and it's not hold 1.3 bar of pressure anymore and just overflowing.

[mbmO8]

Thank you very much, that’s me swapped over the cap for a spare one I had and I’ll get back to you after my ride today

P.S. the head gasket is all on the right way as I could just see the “up”

[Calum]

Good, sounds like you've ruled out those two main issues, so it'll be something simple. Radiator cap is a usual suspect.

[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 🫤 …