PHF - Pump Jet info

olslewfoot

olslewfoot

New member
Location
Norwich, Norfolk, UK
Dear All

During an investigation into a misfire I was suffering recently on my series 1 Mirage, I discovered that one of the Dellorto PHF pump jets was damaged at its tip and not working properly (if at all!).
Further damage to the body of the jet was revealed when I removed the pump Jet holder.

Two questions really:
1. Its difficult to see on the Dellorto parts diagram how the jet is fixed into the body. Is it a push fit into the carb body and then held in by the jet holder screwed over it? Or does it screw in itself? Its certainly not coming out easily and will probably have to be drilled out. Any advice gratefully received!

2. Given that I may well destroy the original in removing it - the Dellorto website site lists about 40 diffent sizes -  does anyone have an idea which size (or range of sizes?) would be right for a Series 1 Mirage).

I run 135 main jets with airbox and airfilter in place.

Thanks

John
 
Pump jet is held in by the big brass screw, just a push fit, they can get a bit stuck either on the O ring or with a bit of corrosion/fuel gum if they have not been moved for years. Strip the carb body from the rack and remove the slide, lay a suitable drift over the choke end of the jet and give it a tap, very unlikey it requires resorting to the drill.
  #35 jet to replace it but do check, jet size is stamped on the squirty end of the jet.


    Keith.
 
The jet is located in the carb body with a "D" scallop so that the orifice will always point into the inlet side of the engine, after you have undone the large brass cheeshead screw it should also withdraw the jet, as it "clicks" into a holder which is the inner part of the screw, if it has jammed in the carb body, I would suggest leaving the body on the bench with the threaded hole uppermost, and squirting in some Wynns carb cleaner, then leave it overnight, it should then come out with a "push" from the carb throat side, the Wynns is pretty good at disolving the brown fuel gum, and does quite a good job of wrecking the O ring as well, all of which is good.
CLEM
 
You must log in or register to reply here.
Back
Top