Ethanol is likely the culprit on the majority of poor running small engines, 2 or 4 cycle.
I fought with this issue for years especially in my 2 cycles. I ran all of the typical ethanol treatments, helped but problems still came back. I ran across a product called "Mechanic in a Bottle" that was designed to help poor running engines due to ethanol (see below). I figured, what can it hurt, bought some and was amazed at the results! I had a poor running generator that had a 4-position choke lever, I had to leave it at the highest choke setting to keep it running. After using "Mechanic in a bottle" it will allow me to completely turn off the choke. I have used it on multiple chain saws and weed eaters that were extremely poor running, worked on all of them! I have even used it on a couple that would not run at all, simply flooded engine/carburetor with it, let it sit 1-2 days, started up after flushing. The older engines are not designed for ethanol, the newer ones seem to fare better. Before anyone does anything drastic, try it, at best you will be out $5 for a bottle.
"Mechanic In A Bottle is the solution to FIX poor or non-running 2 and 4 cycle engines due to modern fuel issues. This synthetic fuel additive removes all varnish in the fuel system without having to remove the carburetor, removes carbon deposits and water, revitalizes rubber and plastic components, replaces lost octane and rejuvenates old fuel."
Have you noticed that in the higher humidity environments your gas cans with ethanol-based fuel will turn black, actually gets a fungus/mold on it. This can also be seen at all fuel refinery's, storage areas, all of their tanks or lines that carry ethanol-based fuels will get this mold. It is also prevalent around whisky/bourbon distilleries and storage/aging warehouses. The fungus literally grows and covers everything, this is from the evaporating ethanol. Google the multiple articles about MGP Distillery in Greendale Indiana and their legal issues and problems with the local residents, will show pics of their cars and houses literally covered in this fungus however deemed harmless to people.
Morale of the story; use ethanol free fuels when available, when not available always use an ethanol shield/treatment in your fuel. When having problems with your small engines, give "mechanic in a bottle" a try, what do you have to lose. Alot of the service stores/technicians use it on customers poor running engines and charge high dollar service fees, they love issues related to ethanol, easy money for them!
Disclaimer, I have nothing to gain from individuals purchasing this product. I am simply a consumer like you that is trying to rectify issues with poor running issues due to ethanol.
Good luck
Millerish
I had a fuel terminal customer when I still had a job. That black funk was everywhere.
I like the primer bulb until it rots out.
