Yes, Sea Foam is safe and effective in a Vespa GTS125. Use 1 oz of Sea Foam per gallon of fuel if you are adding it to every tank, or 2+ oz per gallon for periodic cleaning. I like to add a high concentration (4-8oz per gallon) to a low tank of fuel (1-2 gallons) and run it until almost empty. That lets you take advantage of the high concentration of Sea Foam for the best/most efficient way to clean.
Yes, Sea Foam is safe and effective in a Vespa GTS125. Use 1 oz of Sea Foam per gallon of fuel if you are adding it to every tank, or 2+ oz per gallon for periodic cleaning. I like to add a high concentration (4-8oz per gallon) to a low tank of fuel (1-2 gallons) and run it until almost empty. That lets you take advantage of the high concentration of Sea Foam for the best/most efficient way to clean.
Hope that helps!