At 08:26 PM 11/7/05, wolfbj@bellsouth.net wrote: <in part>
>I have a leak from both of the fuel delivery tubes to
>the jet assembly. The leak appears to be coming from either the tube itself,
>or from the fitting where it attaches to the bowl. Both M0$$ and V* show
>this as a Jet Assembly. Yet, my SU tuning book shows this as a flexible
>hose with a ferrule, sleeve nut, washer and gland on one end. It does not
>describe what is on the other end.
======
Brent,
Great news it's running! There are certainly some fuel and rubber
compound compatibility issues around. I had a similar problem on my Mini
which suffered from reformulated Milwaukee's best gas. I suspect in the
near future we will all be experiencing similar failures. (Cap'n Bob will
no doubt pontificate on RONs and Pons or whatever.)
Back in the 70's I assembled SU jets for an aftermarket
manufacturer. Not the ones Frank mentioned. These were extremely similar to
the original SU ones, and were shipped all over the world. The clear
plastic tube was swaged onto the plastic jet end, and the other end, as you
said, had a ferrule, gland nut, washer, and o-ring. Several possible things
can cause leaks.
We had a rather large run of tubes that were miscut such that the
tube was pinched in the slicing process and would crack either immediately
on installation, or
disturbingly soon after. Luckily this was before litigious lawyers. We
solved that problem.
Often folks would not remove all of the original o-ring or even
the brass washer. Check for that. Look at the o-ring to see if it has gone
soft from the gas issue above. Also, be careful not to over tighten the
gland nut.
Now, the kits or jets to which Frank refers are made by another
company, Royze in California. They make a generic SU HS jet. 2 part numbers
cover all HS SUs. 1 has a .090" tube ID, and the other has a .100" They do
not look as original. They provide a plastic pipe fitting for the bowl with
a barb, and a plastic holder for the jet tube also barbed. You use a rubber
hose, provided, to span the gap. SU jets are "handed" meaning that the
plastic is so constructed that there is a front and rear for the choke
lever arm to attach. The Royze jets use a different molding that is
ambidextrous. SU original style jets have a front and rear for .090",
.100", and Spitfire .090". Six basic part numbers. The Royze jets are
easier to stock, naturally. Also, the Royze jets are aluminum with the
brass orifice inserted. The originals are brass.
Personally, I feel the Royze jets are a compromise; but, then I
worked
assembling knock-off "real" ones.
That's the story as I see it. See you at SOS this year?
Peter C.
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