My log splitter engine recommendations say to decarbonize the engine at 150 hours or so. Is this really necessary? Will it add to engine life and performance. Seems to be running fine, I change all the fluids, filters, and plug.
You don't say how old your engine is. If it was made in the 60's or 70's, there still was leaded gas being used. The lead in the gas is what caused the carbon build up. Now days that is not an issue.
If the engine is running fine as you say, I would not bother with the decarbonising the engine. You may want to use the ethanol free gas which in my area has a higher octane rating than the 10% ethanol gas. The carbon build up will increase the compression ratio which would normally require a higher octane rating.