Does anyone here happen to know about Solex bus carbies? My bus played up again today. Sometimes she's just sulky, other times has a full on hissy fit and will barely go in second. Today it was a mega-hissy fit.

So I pulled over, and as I had cleverly put my tools in the back, I thought I'd have a quick look at the carbies. Well, I took the top off each one, and saw that the left one (over cylinders three and four right?) had much less fuel in it than the one on the right (without the idle circuit stuff) (left, about five mm max, right, maybe a cm+half, maybe two cm).

So I siphoned some fuel from the tank, poured it into the float bowl, put everything back together, and voila! She drove like a dream, accelerating smartly and everything. What a joy.

Now the thing is, I'm not quite sure what's going on. Surely the level in the float bowl would drop and the problem would happen again quite soon if indeed there was a problem there, say with the float (which does still float). She drove home the whole way perfectly. I was really happy for a while as I thought that I had solved this year-old problem, but thinking about it, I'm not convinced just yet.

Sorry this is so long already; I'd better wrap it up. Does anyone have any ideas?

Thanks, Aurel

From the sound of it,looks like its getting fuel but maybe too slowly(fuel line to the left carb partially blocked or filter full of crud if it has one).Im only guessing ,but keep plugging away the good news is that u know it is fixable.

Brad has some top quality fuel filters these are clear with a water float and a tap so you can turn the fuel off , run some metho in your fuel tank say a ltr or two

Yep, the comments above sound on the mark.
I'd also give the carbs a good clean and remove the float needle, I have seen dirt traped in one which caused intermittent fuel problems.
Richard

Ah, good. Intermittent is right, grr!:cussing

There's a filter before the fuel pump. I read that it might be good to have a high pressure filter (?) after the fuel pump to get rid of small debris from the pump, but that was for FI systems. I checked the line between the T-piece which splits the hose to each carby - both sections seemed OK. However, I do intend to replace all the fuel lines anyway, busses being busses, I'm not too keen on mine going up in flames!:o

Thanks. Any more ideas welcomed also!

The stock mechanical fuel pump for dual carb motors puts out ~4psi and it is OK to run a standard plastic filter either before or after the pump. I recommend only ONE though, not one on inlet and outlet.
It's also a good idea to keep the filter outside the engine bay, that way any leaks there are less likely to to do damage.
If you mount the plastic fuel filter vertically (in bottom, out top) they will separate water out as well.
It's interesting to not a paper filter (as most are) swell when water touches the paper, and even though they look clean the can be blocked.
Definitely replace lines and filter though to be safe.
:thumb

it could be low fuel pressure from a worn fuel pump push rod

Well, if it is indeed low fuel pressure due to a worn pump pushrod, I'd be mightily peeved. When I first got the bus, about this time last year (oh round a bout anyway), I paid a Volksy mechanic to do a 'complete service', and fix the dying problem that the car had. Now he reckoned it was the fuel pump, a brazillian one, so he replaced it (incl. pushrod) with a 'rekitted' 2nd hand one, and I paid $200 for the pump incl. fitting. Including various other stuff, I paid $800 all up. Not happy.

Now the fuel pump leaks a little oil, one fuel line (going up to engine) interferes with a piece of curved tinware, preventing it from sitting correctly, and she still has a dying problem (though it is less severe!).

I feel really ripped off.

What's worse, is that the silly fuel pump has a weird not-quite-allen-key bolt thing instead of a good old hex-head or allen key bolt. Why?

Grrr!:cussing

I've got a spare pump from another (1800) motor, I'd put it on if I had the right tool. Any ideas? (I got this pump off the other motor by hammering an allen-key into the not-quite-allen-key bolt to get it out, but that probably isn't too good an idea when I need to fit it back in place hey!)

Bla bla bla, sorry to bore you all! Thanks for the ideas folks.

Check the other suggestions before blaming the pump/push rod if it was fixed 12 months ago.
The pump is held on with bolts with a spline inside (same as CV's) It's a "double hex" and an allen key will work in a pinch (as you found out).
It is best to get the correct tool though, they are avaliable. I got one from Repco, price was OK, but quality is not too flash.
If you have a manual, you can check the output of the pump without removing it also.
Richard

Oh that's handy to know, thanks.

I also have a spare fuel pump and pushrod. Not sure of the condition of either, but the pushrod doesn't show any signs of wear. When I get the tool, and it's time for the next oil change, I'll have a look at the pushrod I'm currently using.

Merci,
Aurel.

Push rod is easily checked, it should be 140mm long.
I have seen them warn up to ~4mm short!!!!!!!!