Given the short lifespan of the G2 (3-260) Carburettor, does anyone have any further details on when and why the change was introduced to the Air Vane (flag) shape and what models it effected?
Parts Amendment List 2 February 1969 shows a "full" flag whereas A.L. 4 Feb 71 shows a "truncated" flag, both 3-308.
I noted in the workshop manual the advice, "If more engine speed is required, cut away the top corner of the vane as illustrated", but assume this was an interim solution until the new truncated Vane design was introduced.
I also noted the change to the Governor Spring (3-279), with the comment, "A modified spring with more positive attachment at the lower end is now available"
Were both of these design changes attempts to solve 1969 period "in the field" problems prior to the G3 introduction?
The great Mr Davis has spoken about this carby. To me, the design reeks of a then typical Victa rushed job. They wanted a governed carby to meet industry expectations.
It's clear that the industry safety policy of 1968 for all AUS lawnmowers required a positive engine stop mechanism - a magneto cut-out. [Not the archaic 'closing of the throttle'].
As you know, the G2 had an external handle-mounted cut-out. It may be that the G2 was an interim rushed job that the G3 corrected in due course. It gave Victa more time. Is that a fair point?
Bringing the cut-out 'on-board' combined with a more responsive - and adjustable - governor vane was the goal. Plus, the use of more plastic parts may have been a commercial bonus.
I do not think anyone here was aware of the flag changes to the G2. You have a better understanding of these things than I do.
Many thanks for bringing this bit of history to our attention.
Victa said this below on the G2 Patent. For many years-speed governing in such engines has been achieved by positioning in the path of the cooling air stream a light-weight flag-like member,the vane of which is- displaced by the air -flow to rotate its spindle for closing down the throttle control valve as the engine speed increases.
The first G2 carby obviously wasn't working correctly so the 2 amendments (flag and spring) were made to fix the problem until the G3 came out.
G'day Max and ODK members Of course, absolutely brilliant research there Max! [I don't think that's the first time I have said that]
My feeling is that Victa, time-and-time again, rushed the job. I mean, governed engines had been around for well over a century. Victa were way-too-slow to come to the party. [ And if ever a mower design needed a governor it was the rotary!]
I think Victa solved two issues with the G3... [1] How to adjust a air-vane governor without the silly G2 procedure. [2] How to have an onboard carby engine cut-out.
I think they did a good job on the G3, but rushed the G2. I hope these are fair comments.
Thanks for the positive comments Jack ,great to see all your brilliant research here too.
Yes I agree the G2 is like the first Brass nut Victa carby ,it had design flaws.( the brass nut carby coming loose on the mounting spigot)
The brass nut carby was usually upgraded to a later model carby just like the G2 was usually upgraded to the G3 carby.
I've seen old mower shops with 20 litre drums full of G2 carbies ,the serviceability of the G2 was no where near as good as the G3 carby. The G3 was a big improvement over the G2.
I would think Victa had seen all the Briggs and Stratton air vane governors before they made the G2 and G3 carbies.
