PD46 carb connecting fuel pipe o rings - THE answer

[Ashdowner]

With thanks to Gerben in Holland, I just want to share that Viton rings with an outside diameter of 9mm and an inside diameter of 5mm absolutely fit the bill. They're a smaller id than the originals but a bigger cross-section at 2mm, but they feel like they've really seated solidly when you put the tubes into the carbs and I've leak tested them today with 100% success. They're available from the major stockists.

[deltarider]

That is, if they need replacement. Mine have been in there for over 40 years and still don't leak. And I mistreated them every time in the struggle to get new fuellines over the nipples of the T-joints and had the carbs move vehemently. Can't thank Honda enough to fit two O-rings on either side.

[Seabeowner]

Delta, On my Pd46 (78)carbs there is a single fuel feed to carb 2 and then the three jointing pieces but with only one O ring each end (six in total). (There is a ridiculously priced kit of tubes and O rings available) Perhaps it was to save pennies or perhaps as the are not a fuel inlet and cannot rotate once in place it was considered adequate. Certainly a whole bunch of O rings are available on ebay and often next day dely (sealforce)and much cheaper than through other channels.

[deltarider]

Oops, I didn't notice it was about PD carbs. Sorry for that. Anyway, on the old style carbs with two T-joints there are two on either side, so 4 per T-joint and 8 in total. I always advocate NOT to separate the carbs from the rack unless it is ab-so-lu-te-ly necessary. When they leak, the O-rings need to be replaced ofcourse, but if not, leave them, as they can go a looong way. Mine are 40+, have been mistreated and nevertheless seal well. Maybe the reason that they live so long, is that I always keep my carbs (and the fuellines above them) "wet" during hibernation, be it that I drain the floatchambers every two months (the collected fuel goes back in the tank). Before I open the petcock to let them fill again, so with the chambers stiil empty, I turn the idle adjust screw so far loose that the carb slides are all the way down. I then kick the kickstarter a few times and hope all jets (and the pilot jets in particular) are blown (or should I say sucked) clear. Always worked for me. The only time I had the bike hibernate with the carbs "dry", I was shocked the next spring how much the floatbowl gaskets had shrunk and I then concluded that if the same had happened to the 8 O-rings at the T-joints, that shrinking could not be good for them. Hence my practice. Just my two cents.