1971 MGB GT - Float valve replaced, fuel leak problem now (hopefully) fixed - see page 28

[SiC]

Find a nice fitting socket and a decent length wrench with it held in a vice or similar. It'll shift.

What is the tip of the needle condition like?

[Peter C]

34 minutes ago, SiC said:

Find a nice fitting socket and a decent length wrench with it held in a vice or similar. It'll shift.

What is the tip of the needle condition like?

To do that, I would need to remove the float and the pin that holds it in place is, you’ve guessed it, stuck.

I wouldn’t know the difference between a good and bad needle tip.

[SiC]

21 minutes ago, Peter C said:

To do that, I would need to remove the float and the pin that holds it in place is, you’ve guessed it, stuck.

I wouldn’t know the difference between a good and bad needle tip.

The pins just knock out with a hammer and small drift. One end of the pin has a knurled section to stop it readily sliding out. A sharp rap should be sufficient. Iirc the position and length of it is sufficient that it won't fall out when mounted inside the float chamber. 

[SiC]

22 minutes ago, Peter C said:

I wouldn’t know the difference between a good and bad needle tip.

This is what picture uploads are for. 

Basically a worn needle will have a ridge on the tip. A new needle doesn't. 

 

[Mally]

23 minutes ago, SiC said:

The pins just knock out with a hammer and small drift. One end of the pin has a knurled section to stop it readily sliding out. A sharp rap should be sufficient. Iirc the position and length of it is sufficient that it won't fall out when mounted inside the float chamber. 

Pretty sure it can't fall out when assembled due to the casting of the base.

Edit, I've had bad new needles .

[Matty]

2 hours ago, SiC said:

The pins just knock out with a hammer and small drift. One end of the pin has a knurled section to stop it readily sliding out. A sharp rap should be sufficient. Iirc the position and length of it is sufficient that it won't fall out when mounted inside the float chamber. 

From memory its one way in, one way out for the pin. So if it won't shift try the other direction. Pretty sure one hole is slightly larger than the other.

(May have this confused with sidedraught Webers)

[SiC]

2 minutes ago, Matty said:

From memory its one way in, one way out for the pin. So if it won't shift try the other direction. Pretty sure one hole is slightly larger than the other.

(May have this confused with sidedraught Webers)

Yeah I think that sounds correct. It's likely you'd want to hit to get the knurled end out only one side and not have to knock it through both holes. 

[High Jetter]

Sound plan

[Verysleepyboy]

I have found that a sprung loaded automatic centre punch is ideal for knocking the float pins out without resorting to using a hammer and punch on a flimsy casting. The shock of the punch trigger is usually just enough to get the pin moving out and it easier to wield in situ.

[Peter C]

I took the wheels back to the tyre fitter.

One wheel was 30g out, the other was spot on.

Would a 30g imbalance cause such violent vibration? Not sure. Anyway, all sorted now.

I was perving at HMC's dashboard photo this morning. I love photographs of cosy dashboards.

After I overcame a massive* erection, it dawned on me that I should have a fire extinguisher in my MGB.

As I don't have an accessible but safe place to put one, for now I've tucked it into the spare wheel well.

I removed the float chamber cover again.

I managed to remove the float pin. It actually came out quite easily.

Then I removed the valve, which also came out easily.

I gave it a clean with carburettor cleaner but there wasn't much wrong with it.

@SiC This is the state of the tip of the valve. Looks brand new to me.

I'm taking the MGB to London this afternoon, to see my parents, as it's Mother's Day tomorrow.

Wish me luck.

 

[SiC]

The camera has focused more on your hand than the tip so it's hard to say. But it does look like there is a worn in ridge on that tip. It should be completely smooth to the tip. 

[SiC]

This was the one in my MGB. Notice the worn ridge. This won't seat properly and can/will leak. That doesn't even look as bad as yours either. 

This is a new needle. Ignore that I overtightened the bottom bit and snapped it 🙃

Notice how it's smooth. Also these newer tips have a coating to reduce the wear.

[Dj_efk]

Yep that needle valve is fubar’d Pete, change it asap.

[Peter C]

3 hours ago, Dj_efk said:

Yep that needle valve is fubar’d Pete, change it asap.

You might be right.

I got as far as the end of my road and noticed a strong smell of petrol. The float chamber was pissing fuel out via the overflow pipe.

I put the MGB back into the garage and drove to London in my Nissan.

 

[Peter C]

This looks like what I need.

[Dj_efk]

That seems very expensive for what you get?? 
 

I would check eBay etc. in case my instinct is correct….

[Peter C]

1 hour ago, Dj_efk said:

That seems very expensive for what you get?? 
 

I would check eBay etc. in case my instinct is correct….

I’ve now ordered this one.

[Dj_efk]

I always found Moss and Rimming Brothers to be expensive when I ran classic Brits back in the late 90s / early 000s.  I see that’s still the case.

[SiC]

On carb stuff I generally only go genuine Burlen (SU branded) as, while they are expensive, the quality is almost always top notch. Too much cheap shite in all the car parts world and I'm getting fed up dealing with variable quality. So happy to pay more to keep a manufacturer in business if they haven't let the accountants forced manufacturing/engineering to cheapen up. 

[Matty]

13 hours ago, SiC said:

On carb stuff I generally only go genuine Burlen (SU branded) as, while they are expensive, the quality is almost always top notch. Too much cheap shite in all the car parts world and I'm getting fed up dealing with variable quality. So happy to pay more to keep a manufacturer in business if they haven't let the accountants forced manufacturing/engineering to cheapen up. 

The other thing with dealing with Burlen is if you aren't absolutely sure what you need, just pick up the phone and speak to them. 

[Peter C]

The new float valve arrived today.

Looks legit.

I had it fitted within 10 minutes.

As my wife's car was on the drive in front of where the MGB sleeps, I didn't do a test drive but I fired up the B-Series and let it idle for a few minutes. No fuel leaks, engine ran fine.

Hopefully now sorted.

Question. The back end of the valve (the float end) is spring loaded. Why? Pressing on the back of the valve doesn't open / shut anything?

[SiC]

I've always assumed as it takes up the slack when the float valve is pushing up but also means it'll compress before the spring metal of the float valve would start to get out of shape. 

[High Jetter]

It's right, something I recall from BITD. SiC may well be correct, SU knew what they were doing.

[Westbay]

@SiC & @High Jetter both right , it adsorbs the impact so the needle jet isn't 'hammered' into the seating causing premature wear ...