[Landlover99]

I don't have anyone to operate the key so have to do the testing myself. All I know is, with the pipe on the left disconnected as shown in the photo (and I assume this is the pipe from the fuel pump via a filter) turning the key for a second or two results in a wet patch of petrol on the inlet manifold under the disconnected pipe. Because I'm turning the key, I can't see where exactly the fuel is coming from, but I assumed it's from the disconnected pipe. The seller did say he'd had the carbs off due to a "flat spot" he'd been unable to correct, however, it did run for a while after I took delivery of it so I don't see how the carbs could be on the wrong way around.

 

[marjon]

I don't have anyone to operate the key so have to do the testing myself. All I know is, with the pipe on the left disconnected as shown in the photo (and I assume this is the pipe from the fuel pump via a filter) turning the key for a second or two results in a wet patch of petrol on the inlet manifold under the disconnected pipe. Because I'm turning the key, I can't see where exactly the fuel is coming from, but I assumed it's from the disconnected pipe. The seller did say he'd had the carbs off due to a "flat spot" he'd been unable to correct, however, it did run for a while after I took delivery of it so I don't see how the carbs could be on the wrong way around.

If you cant see it dont "assume" it comes out of that pipe .
If you are on your own just tape a couple of little ziploc bags/ballons/ condoms over each end then you will know which way the fuel is flowing.

J

 

[Landlover99]

That's fair comment indeed, Marjon. But when I made that assumption I was unaware there was a return pipe. I simply assumed (yeah, that word again) that for some reason, each carb had its own fuel feed.

 

[Hicap phill]

Make a starter button for working under the bonnet.
Leave ignition on & press button & watch for leaks

 

[Landlover99]

Yes, that would have saved me all sorts of time when I put the electronic ignition on it! I must get one of those; I was told you can get 'em off Ebay and I must have a look as a priority. You can't get anywhere near the solenoid on this model as it's buried right underneath the lump out of sight.

 

[Stanleysteamer]

That's the problem with this type of carb. As you can see from the photo, the float chambers are the concentric (to the main jet) type and there's not enough clearance to remove them separately. I prefer the older design with the float mounted remotely and connected by a fuel bridge as you could further isolate the fault with those.

Me too, but it looks like you are going for a strip down and clean up anyway, rather than just getting them working quickly.
I just hope that your work with taking them to bitz and ultrasonically cleaning them doesn't end up with you having to retune them too much.