willysmjeeps.com

Hi,

I've been planning a long trip in my jeep and wondered if I should worry about the my YS 950 with changes in altitude

The F head was sold to me with a tired Carter YF which was really fiddly at different elevations.

I'm a lot happier with the 950 so I'm hoping it copes better, any thoughts?

Brett?
RickG?

Either of you guys have this carb?

The Army who operated the M38A1 around the world never bothered with a substitute main jetting for the YS950S so I see no need for us to try now. In most cases attempting to modify jetting on any carb for higher altitude operations will result in poor performance at the lower altitudes so the normal advice is to not change jetting for altitude changes unless you intend to only operate the jeep at that new altitude.


Note that the main metering jet is variable and vacuum operated in the YS carbs. The civvy WO and YF's use a mechanical adjustable metering rod.

Thanks for the info Wesk, that puts my mind at ease