I think going back to regular bar will not solve the problem. You first have to figure out the true cause of the problem.
PLEASE, IF ANYONE HAS SOME ADVICE AS TO WHAT TO DO!
Thank you.
Talk to a saw shop technician. Ask him, "of the last 100 failures in oiler mechanism components (oil pump, pinion gear or tubing), how many were using vegetable oil?"
And then consider in the history of chainsaw use, like in the last 80 years, of all the oiler problems ever encountered over time, how many were using vegetable oil? Probably none.
Then ask at what time of year most oiler problems occur, it'll be Winter because regular bar oil gets more viscous the colder it gets, vegetable oil does not thicken as long as it is in liquid phase.
The answers should clearly tell you that oiler component problems do happen, and not because vegetable oil was used because up until very recently ONLY bar oil was used and even now only a tiny fraction of saw users are using veggie. Oiler problems have always, and will continue to happen. I don't think veggie oil will be a cure for that.
And Greenstar, of that pool of veggie users a very tiny few, over time, have stepped up with a true problem.
Where and why you're having a problem with all your saws, all at once, I can't say. I have to assume you clean out the bar guide rails, make sure the oiler hole going onto the bar is not obstructed and that the thin metal plate that the bar seats onto is also free of obstruction. This goes for all saws, regardless of veggie or petro oil. Sawdust gets into these areas, it is just what happens in chainsaws. Without regular inspection and cleaning oil flow will be blocked. When this happens the pump can be pumping fine, but oil is not being pumped to where it needs to go. Resistance builds up, components work harder and the weak link, which is often that 5 dollar plastic pinion gear that turns the oiler pump will strip out. It's an easy, in-field fix if you have the new part in hand. I know this because every homeowner saw user who knows me will ask if I can look at their saw and see why the oiler is not working. I've pulled dozens of these apart. Usually it's something clogged with sawdust. They've ALL been using regular bar oil.
Once the bar and chain are off, fire that mother up. Oil should be pumping out the side case. If not, inside of 3 minutes you should be able to pull the clutch, spindle bearing and sideplate to have a look deeper inside. At that point the plastic pinion gear can be pulled and inspected. Use compressed air and a tiny carburator screwdriver to pick around and clean the recesses (this should be done every few months, regardless of veggie or regular bar oil).
Lastly, consider this: Do you, when opening your gas and oil caps, crack open the cap, blow/brush the sawdust away from the cap rim, then open the cap fully? Do your groundguys take this step? If not, sawdust will fall into the tanks and as far as oil tanks, I don't really know if saws have a filter for bar oil. If they do, sawdust will cake the filter. If not, sawdust will get sucked into the oiler mechanism and transfer tubing.
These problems, as you can see, are not necessarily related to veggie oil or bar oil, but rather sawdust getting into places we rather it not be. With care and attention and some regular cleaning one can minimize this to some degree, but a saw makes sawdust. I don't know what else can be said about that.
I don't think veggie is the problem. This will be my 9th Winter using veggie oil, the only thing I do differently is use only canola in the deep of winter, rather than corn, soybean or blends like the rest of the year. Canola stays liquid to the upper teens/low 20's