Head gasket problems

[boyd]

still no sign of gasket arriving, I'll wait till it gets here to open her up again.
I've had a look inside the tank and I've noticed a lot of flaking, I had a go at collecting it with a magnetic tool and I've noticed that it isn't metallic, I think it may be some kind if tank lining, Kreme or another type, I'm wondering if this is blocking the fuel flow. It isn't present t in the banjo fuel filter but as the flakes are quite large, it may be happening inside the tank? Would this cause power loss under acceleration? Time for a tank clean out I think.

[saltbox alf]

It could well be old lining material coming off in the tank. Some fuel taps have filters inboard of the tank and if so, could well be blocked. It sounds like a thorough tank clean is called for.
Never ending story these bikes of ours, innit!!

[Janet]

Would this cause power loss under acceleration? Time for a tank clean out I think.

Particles around the petrol tap filters in the tank may be allowing enough fuel through for easy running but when you accelerate the bike needs more, in which case it could be restricting the flow enough to make a difference.

[Ozmadman]

Would this cause power loss under acceleration? Time for a tank clean out I think.

Particles around the petrol tap filters in the tank may be allowing enough fuel through for easy running but when you accelerate the bike needs more, in which case it could be restricting the flow enough to make a difference.

Those fuel filters in the tank are a pain in the neck, I have removed mine and rely on the one in the top of the carb. The problem is that once they get blocked it's a tank drain and tap removal to sort out and then you have to get them to seal again etc etc etc.. At least the carb one is a doddle to sort out
Paul

[boyd]

Ok that all sounds like good advice....again.

I have a length of chain to put inside the tank and shake around and clean up some of the loose flakes. if i take the taps out, whats the reseal process?

Im guessing it might involve a pain in my arse?!! I was thinking plumbing tape or gas fitting tape. Is this likely to be petrol resistant?

Hoping this may cure some of the drama.

This bike is definitely taking up any spare time I was worried about!!

[Janet]

I don't bother much with the threads that screw into the tank, apart from making sure they're clean and undamaged but I make sure there is a good flat seat between the tank and the tap. Some people use Dowty washers to seal here but I've never have any success. I've used fibre washers for years but check them for squashing after a time.

[RAY BOWMAN]

Hi
I seal mine with a couple of turns of plumbers PTFE tape and fibre washers.
Ray.

[Ozmadman]

I use these 1/8gas(BSP if it is a lightweight) from hitchcocks, they seal first time every time, you can get them in other sizes too, copper outer with rubber centre

[Ozmadman]

What's happening with the head gasket or lack of it??
Paul

[boyd]

Sorry for delay getting back, I took the head off again and cleaned up the surfaces again, filled some small pitting with some liquid metal.
On closer inspection the head and block look the same as yours, but they have both been machined at some point. The recess that the copper ring of the gasket sits in is much shallower.
I tightened everything up and the head seems sealed now. But problem was not solved. I also cleaned the tank out by shaking a chain around inside, then rinsing and drying. The petrol taps were very blocked, so I thought I'd found the problem.... But...I put everything together again but still have the same issue. The bike starts and runs but then starts popping and chugging, then won't start after it cuts out. I'm running out of ideas and possible scenarios!!

Where do I check the points and advance / retard?
also how do I check if the float is set correctly?

I've changed the spark plug and oil and cleaned the jets at this stage, and I've done a general checking of wiring connections Am I missing something obvious?

Boyd