MRC Forum- brought to you by www.morini-riders-club.com Member: g7AW3f

Hi.
350K.
Unscrewing the pilot screw and the throttle stop screw on both carbs I see no o rings at all.
I believe they’re supposed to be there although not sure exactly where.
It seems a bit unlikely that all four would have accidentally been lost.
Do they dissolve in time?
Can anyone shed some light please?
Thanks.

They should be there. The mixture screw one may be inside the carb so double check with a torch.A squirt of carb cleaner would not go amiss.
All obtainable from Eurocarb. Actually I did not have any on the mixture screws in my K1 for years ( a senior moment) and it made no difference.The idle responded to the position of the screws as it should.
John

Ok John, thanks for the reply.
Off to Eurocarb site, may as well get a couple of 43/44 pilot jets as well as that seems to be the received wisdom.
Cheers.

I have seen many, many carbs with no O-rings fitted. In fact I'd say most that haven't been rebuilt have had no O-rings.

EVguru wrote: ↑17 May 2021 21:19 I have seen many, many carbs with no O-rings fitted. In fact I'd say most that haven't been rebuilt have had no O-rings.

I agree with Paul, I have seen many without o rings.
An English translation of A Dell Orto document I have by Contact Developments of Reading (precursor to Eurocarb) from the
1970s shows no o rings. Critically this applies to the VHB BS carburettors so pre dates 1976/7 and the introduction of VHBZ BS carburettors
I would expect by the VHBZ HS carburettors (1979) for these O rings to be present as they are shown in the drawings. Evolution of these carburettors
likely for emissions reasons as extra washers/rings etc would add extra manufacturing costs.
Whether fitted or not unlikely to make any difference as John says. What is worth checking is that there isn't a stack of lost and forgotten
washers and o-rings hiding at the bottom of the mixture screw hole.
Cheers
Mark

Yes, on subsequent investigation I too found old diagrams showing no o rings.
I shall indeed poke around to be sure none are there but it seems that none were ever fitted.