Hello there Rovert, and many thanks for the reply.
I've set those mix-screws to lean in order to eliminate the exhaust smoke that would otherwise arise due to the higher-than-normal amount of oil that I add to the petrol. I like to use a slightly oilier fuel mix so that I can be confident that every drop of fuel that's running through the crankcase is nice and slippery for the sake of the moving parts down there. I figure that any increases to engine temperatures that might result from running things a touch lean will be mitigated by the fact that I never run the unit flat out anyway.
As for killing the unit by using it at part-throttle, I'd say she's not doing too badly regardless, given that she's now going on for 20 years old, and has had to look after an average of 5 suburban-sized lawns over all of that time. The only thing I've ever had to replace that might be due to low-speed use has been the clutch drum. But I'd sooner fork out for a new clutch drum every 20 years or so than to end up butchering the edges like a lot of the contractors that I see working in our street. Our edges are manicured - not gouged. Besides that, I easily get 4 lawns per tank out of her at the speeds I edge at, and I'm fairly certain that I used to get 5 back when we had 5 lawns to look after. So the fuel and oil we save would easily pay for a new clutch every decade or so...
Look, you've got me there with the term "8 stroke"(?). Is it a "burble"-type of thing? You'll have to elaborate a little so that I'm clued up in the event that I play around with the Intlet Needle Lever, and consequently need to give her a re-tune.
Best Wishes,
Moby Mick.
