Actually, I run my Homelite weedwacker at a speed just off-idle. I've run it this way for the last 8 years without so much as a plug change or de-carbonizing.

I run Sea Foam through it once or twice a year.

I run my chainsaw(s) about half to three quarters throttle 90% of the time and one is over 10 years old.

Run your bicycle motor the way you feel comfortable. They will either blow or run forever.

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If it ain't broke, and you mess with it long enough, it will be.