VHB 30 carbs - washers or not?

So I’m rebuilding my S3 carbs - VHB 30mm D(estra) e S(inistra) - which after 20 years of ignorance are not working so well. Same carbs as T3, T3 Cali, G5, Convert etc…

According to the VHB 30 parts diagram on the Dell’Orto/Eurocarb website, both the mixture screw and the tickover screw require a small flat washer between spring and ‘o’ ring, parts 48 and 46 here: VHB carb parts diagram

I seem to remember spotting a washer like this many years ago - it’s not there now. The rubber ‘O’ rings seem to have just dissolved into nothing, no doubt helped by our wonderful ethanol fuel.

So, do you know if your 30mm VHB carbs have a washer - or not? Apart from distancing the spring from the ‘O’ ring, are they necessary?italianmotor2013-07-17 21:28:38

Is that what they are? Never seen any, I just put the O-rings under the springs. Last ones came out a bit squarer section, otherwise OK. Replaced anyway as new ones in o/h kit. But would have kept going. None of my VHB’s had O-rings at all until I put them in, Spada’s ones never did have I think. Wotsisname at Motomecca told me only really necessary if air can leak down the screw thread cos it’s a bit loose, otherwise can do without. HTH

Afterthought ~ struck me last time how the ends of the springs are remarkably flat and smooth, either they’ve been polished flat by rotating or the tiny washers are somehow stuck onto the ends? Not taking one out to check now.

Have had bikes with and without washers, they do not come in refurb kits, most have worked fine without washers but all have needed O rings to have any hope of balancing the carbs properly.Cheers, Gerry.

you can buy the little o rings from Allens performance

Ordered it all as they’re very cheap. Hopefully the bike might run better soon. Once the charging is also sorted. Who knows, maybe I can ride it this year?

'Cause of air leaks down the screw threads, yes.

Well, washers + new O rings = belt and braces

Did my carbs recently. The crucial thing was to set the float height as accurately as you can at 23.5- 24.5 mm. Before I did that I could not adjust or balance the carbs at all. I put washers on mine but they did not have them as bought off e-Bay.

This is a good mention!

Very important if you get the refurb kits for VHB30s from Motomecca or similar to use all the little bits, they are there for a reason and any left overs will be a fail.G.

Just done the NTX carbs and the washers made balancing easier.
Have fun

Yes, will of course check float heights too. Can’t believe I’ve left it so long to rebuild these carbs, apart from adding the odd gasket. Shows that Guzzis run even when not all there…

I was surprised how bad the renewables were in mine, considering they were ‘done’ I think 2003, used 2 years then left mostly dry until now, but still needed everything in the kit and new filter screens. That was probably just the 2 years of use did that.