Vapor lock (fuel boiling)

[KE4AVB]

Gravity fed fuel system.

Well this problem is back again this year for me. Last year was a couple Kohlers this year it is MTD engine. Fuel line temps when measured was 212F, carburetor fuel bowl temp 125F. These are external temp measurements. Darn winter blend fuel in 90+ air temps just don't work, too volatile.

[Skywatcher]

Hi KE4

I remember an old road construction operator telling me they used to add a 2% ratio of diesel to the gasoline in the equipment to stop vapor locking in the fuel systems. This was back in the days of carburetors on gasoline engines. With today's EFI systems, vapor locks are never heard of. Just wondering if the diesel trick would work on these small engines. All the best,

Sky

[NO0C]

Use real gasoline instead of that corn whiskey crap!

[KE4AVB]

I thinking of trying foam pipe insulation to cover the fuel line. I seen an old JD water cooled Kawasaki engine on a rider where JD did this to the fuel lines. The problem is related to it being gravity fed as the air bubbles are blocking the fuel flow. I haven't seen or had problems with systems using fuel pumps. I be sure for tomorrow I be running my 42" Yard Machines mower that has the 21hp on it. Grass at least 6" over grown and the temps are to peak around 95F. It has gravity Feed tank but the engine has a fuel pump. The 21 hp is kinda power boost for the mower since it has a 16.5 hp originally. Thinking I need upgrade top a 5/8 deck belt as it kinda smells on engagement. Anyway at least I can cut in 4th and 5th instead of 1st.

Use real gasoline instead of that corn whiskey crap!

I think with 400F air blowing across the fuel line even regular old gas will have problems too especially with the high humidity we had here today after the rain shower. By the way my fuel is mix using Tequila. Maybe it that little worn that is causing the problem. Most around here say Jack Daniels is too good for burning.