Spent over a week trying to find the genuine Dellorto service kit that I’d bought a few years ago and put away somewhere safe so I didn’t lose it…  Finally got a chance to rebuild the carbs, so spent the evening at the kitchen table following the instructions in Des Hamill’s book. My auntie tells me it was a scene reminiscent of my uncles sat round the kitchen table at my grandma’s some forty years ago, likely doing the same thing. 

The kit includes all the gaskets, o-rings, springs, filters, diaphragms and needle valves you need, so it’s really just a case of working your way round and ticking things off the list. The floats were really badly misaligned and I doubt it was a result of manhandling by the chappie that did the cleaning, so I guess they’d been a ways out for whoever ran them before. Bend, measure, bend, measure, bend the other way, measure, repeat …

The float droop on both sets was originally somewhere around 40mm, compared to the intended 25mm, so that would undoubtedly have had a big affect on something. I can’t think what that big affect would be right now, but it would have been big. You don’t need me to tell you that. Oh, you do?  Well, err, it’s not that it would overfill the bowl, so it must be that it would let it get too empty, so maybe you’d end up with starvation issues if fuel couldn’t be picked up correctly.  You may be able to tell I’m rambling and guessing now 

The main issue that I found was with one of the idle emulsion tubes & jet – in this photo it’s the lower one. I can’t even tell what it is (as the numbers have been worn off) but I do know that it’s not a 7850.1/60 combination like the three others  Note the lack of a hole below the thread.  Only a tenner or so at Eurocarbs for a replacement, but it’s annoying – doubly so if they later get replaced when set up properly. Doesn’t say much for the “specialist” who serviced ’em for the fella I bought them off either, I guess.

The only other issue I found was a load of unplugged holes on one carb that are plugged and fitted with a take-off on the other. It looks like they really ought to be plugged, so as not to destroy the vacuum in that choke. Opinions?

 

So I could at least end the evening with a sense of accomplishment, I quickly put the finished carbs onto the manifold with the new Misab plates and doughnut washers. Nothing’s tightened up yet, but at least it was nice to look at 

Now if only grandma was still here to offer me a ridiculously hot mug of tea and a slice of cake … 

 

Graham: [on the unplugged holes on one of the carbs] correct you can’t leave them open