Amal 75/014 help!

[kjohnson]

Hello everybody!
It’s been a while since I last posted a question on here (house move, kids ect)!
I was just wondering if anyone could help with any advice on early Amal carbs?
I got a 1931 mf350 and but never actually heard it run until this week after many years.
The main problem is fuel leaking from around the Jet block area (the 4 holes above the brass nut)
I have looked online at Amal 75/014 pictures but can’t see one the same, I have the brass block that the jets screw into underneath and also a separate LOOSE brass block that sits inside the carb body with the 1” hole through which the throttle slides into, are these two brass blocks supposed to be one piece? Is my question.
Help would be much appreciated !!

[paul.jameson]

I have 2 or 3 76/014 carbs (that's 76, not 75) and all have a one piece jet block, complete with the 4 holes. I am not aware of a 2 piece variety but I am not very familiar with bikes before about 1935, never having owned one. When using a 76/014, I would expect to see petrol coming out of the 4 holes when you flood the bike to start it, but not otherwise. That said, I do tend to get leakage round the sides of the jet block so I am religious about turning off the petrol tap when I park the bike.

[kjohnson]

Hi Paul
Thankyou for your reply, yes you are right, being impatient as I am, I managed to warm the carb up and drift the jet block out, then proceeded to clean the blackened brass surfaces and found silver solder, so yes these two pieces were supposed to be soldered together, I have since soldered them together and refitted the carb, hooked up the fuel and tried it again - still pours out, I seem to recall reading something ages ago about the float chamber/ fuel level being higher than the jets and that there was a spacer that could be placed between the where the float and the carb body join? Hence lowering the fuel level? Not sure if anyone else has heard of this or if I imagined it?
Any thoughts?
Cheers .

[simon.holyfield]

Hello everybody!
It’s been a while since I last posted a question on here (house move, kids ect)!
I was just wondering if anyone could help with any advice on early Amal carbs?
I got a 1931 mf350 and but never actually heard it run until this week after many years.
The main problem is fuel leaking from around the Jet block area (the 4 holes above the brass nut)
I have looked online at Amal 75/014 pictures but can’t see one the same, I have the brass block that the jets screw into underneath and also a separate LOOSE brass block that sits inside the carb body with the 1” hole through which the throttle slides into, are these two brass blocks supposed to be one piece? Is my question.
Help would be much appreciated !!

Can you post a picture?

I have two comments:
1., the 4,5 and 6 carburetters, similar to the 74, 75 and 76 (and the 274, 275 and 276 for that matter) have a one piece jet block according to a 1930's article reprinted in a book I have. If you've got fuel leaking around there your union nut is not sealing the jet block to the body, and/or the the float is not sealing, which is highly likely! Perhaps the fibre washer is missing. This may be the same size as the one you can buy for the 274 from Burlen - I would have a llok.

2., maybe nothing, but you said "brass block that the jets (plural) screw into underneath". Did you mean jets, or jet? A Binks of that era looks quite similar to an Amal, but has two jets...

[kjohnson]

Hi Simon
Sorry, yes main jet, there is a fibre washer in the brass nut but leak is higher than that, I have taken the float needle out and noticed a ridge worn into the taper, so maybe that could be why it’s flooding ?

[kjohnson]

The attachment IMG_8499.jpeg is no longer available

[kjohnson]

Before I soldered it together

[will_curry]

For what it's worth parts lists of the time describe the jet block as 'Jet Block and barrel, complete'
so I assume the jet block was fabricated in two parts.

[Mick D]

Hi

There are diagrams and parts listings in the AMAL catalogue, (available here), which may be of use.

https://amalcarb.co.uk/books-catalogues.html

Regards Mick

[simon.holyfield]

Hi Simon
Sorry, yes main jet, there is a fibre washer in the brass nut but leak is higher than that, I have taken the float needle out and noticed a ridge worn into the taper, so maybe that could be why it’s flooding ?

Yes, that will be it. You'll need to replace the float needle and hope that the seat isn't too bad. When you get your new needle (from Burlen) you can use something like Brasso to bed it in.

Now, I'm not certain that 276 float needles (which are available new) are interchangeable with the earlier carbs, but personally I would give it a go.

Do you have any machining facilities?