Winter degredation

[peterg]

Finally got it running. It appears that the problem was hydraulic locking.
The rear two carbs are gushing petrol. Presumably the float needles are not closing off the supply and the lack of pressure keeps the pump pumping.

Are the Solex carbs easy to service? Are parts available?

Just to make life easy the starter button isn't working and I am having to short the two solenoid terminals to turn the starter motor over

[JoeF]

First thing to do is try a strike with a rubber hammer, to unstick the valves/float.
It could be the needle valves sticking, or the float itself could be stuck in the chamber and not able to rise. It is fairly easy to get to - undo the main fuel feed banjos, then the three top bolts on each carb, and take the lids off the carbs. The needle valve is screwed into the lid, and you'll see the float chamber in the body. You can then see whether the float itself is stuck. To remove the float you first have to pull out the hinge pin and lever ( which rides up and down on the float top ).
Parts are fairly easy to get as Solex carbs were used on many other vehicles - I got some needle valves from Eurocarb Ltd. who also do jets. The 405 uses the 1.5 ( 150 ) size and it is most likely the same for your engine - this should be marked on your needle valves. If you do replace them, you should match the height at which the valve closes, using the washers under it. This sets the float chamber fuel level.
If you are a BODA member, I would recommend getting the Pegasus Parts set of washers for the main fuel feed banjos. They solve leaks there without having to tighten the bolt too much - this thread in the carb lid is not strong.

For the first start in a while it is always good to use the hand priming lever on the pump as this shows up whether all is well. You can hear the carbs fill up and then the lever should suddenly have no resistance once all three valves are closed properly.

[mikebro]

Originally Posted by peterg

Finally got it running. It appears that the problem was hydraulic locking.
The rear two carbs are gushing petrol. Presumably the float needles are not closing off the supply and the lack of pressure keeps the pump pumping.

Are the Solex carbs easy to service? Are parts available?

Just to make life easy the starter button isn't working and I am having to short the two solenoid terminals to turn the starter motor over

I rebuilt my 403 carbs myself using parts from Gower and Lee. The parts were purchased by the previous owner in 2001, but Gower and Lee are still around and seem to be knowledgable on classic Solex. Classic Carbs also have the parts, but I have no first hand info on this company.

Starter solenoid - if you have the proper one, it will have a mechanical button under a rubber hemisphere on its top. Just press this if the button on the dash doesn't work. My solenoid was open circuit on its coil, which is why the dash button didn't work. AES (and others) have a replacement.

[peterg]

In the end I bought a couple of service packs from Southern Carburetters in Crawley but didn't use them

Took the tops off, cleaned as much of the crud as I could and sprayed the rest. made sure the float was moving (rear one was seized) and the float needle worked (both seized). Reassembled and both were petrol tight, although the threads on the banjo bolt in the middle carb are worn.

Engine started almost immediately but it smoked and took quite a time to settle down to an even tick over.

Now to sort out the choke cable, starter button, solenoid and seized rear brake.

[peterg]

I replaced the choke cable with one bought from Standard 8 & 10 Spares @ £50. Fits well and has the right end for the knob to locate on.