Saturday, 20 September 2014

Dell'Ortos Suck

(in a good way). After a complete carb strip, petrol tank tap off for a de-gunk, and fresh fuel, my CCM now starts as it should, just on the choke. Once warmed up, choke off, the engine runs smoothly through the rev range without coughing. Sweet music.
Stripping the PHM is straightforward, mine is a 40 'ZS1' with no pumper (Dell'Ortos mechanical injector, that my Guzzi, and most older Ducati's, do have - normally sits where the primitive riveted banking plate is).
On the top, there is a mystery tab with the number R-4938 stamped on it. Corsa Italiana raced the bike in its former life as a Supermotard in the '00s, before switching to the much faster Vertemati. Maybe it relates to re-jetting?
Hefty arthritis inducing spring.
Needle is clipped on its lowest of four notches (so sits higher in the bore and gives more fuel). 55 choke jet (45 as standard) cleaned with a fine sewing needle - now with added dayglo cocktail flag so I can add it to my surgical tool kit.
32 idle jet (standard 45 - not sure why one would down-size on that). A very fine hole that only a single strand of copper-core electrical wire was small enough to poke clear. 198 main jet (195 standard).
Also new to my arsenal, kinky Vynatrile gloves. Don't suffer all those nasty chemicals and cruddy nails anymore.
Later today, I'll take the bike to my Mum's farm for a proper shake-down blasting up the rough driveway. BP

4 comments:

Nick said...

Nice job, hope it's worthwhile, hope race goes well

james boddy said...

Just unseized my back brake, very theraputic.

Paul harry Harrison said...

Your jetting/needle clip ect seems a bit strange,a bit of work might have it pulling a lot stronger?

Sideburn Magazine said...

Hi Paul
what do you mean?
the strange scratches?
it does seem a bit rough
BP