Pascal Senior Heliman Location: Paris, France
| Martyn,
What you call the idle needle is actually effective from 0 to 95% of the range.
The main needle works from 75% to 100%.
So you understand this carburator does not work at all like an OS one.
The mixture is actually controlled by the angle at which the needle has been cut and its position
This angle should match the viscosity of the fuel you use.
The viscosity is highly dependent upon the % of oil AND the brand/characteristics of the oil used.
While you are still breaking in your engine (is it an OS 91 FXH ?) keep the setting advised by Jan
Then typically, you adjust the "idle" needle at idle speed, actually slightly above idle, by blocking the fuel intake by pressing it between your fingers.
the engine speeds should slightly increase after a while before the engine stops.
If it does not increase : you are too lean.
If it increases a lot ie more than 50% : you are too rich.
The idle needle of this carburator is not as sensitive as the one of an OS carburator. you can start your adjustment by 1/4 of turn, even 1/2...
Once you get it OK, if your fuel has the expected viscosity (the one expected by the angle at which the idle needle was cut), you are OK from 0 to 95% unless your main needle is too lean.
Synthetic oil should be pretty low viscosity. I never used Klotz, as it is not available in france. It could well be that it is not as fluid as the MG SynthePro which is the reference oil used by Jan and Lotterle.
Does your oil have some Castor oil in Klotz ?
Pascal |