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Av Gas or Pump Gas for 220gpu?


Well-known member
Just out of curosity, but which gas is better for running my 220? i've heard opinions on both sides of the fence, but no real reason behind their opinion as to why...
I'd run pump gas and the recommeded dose of a fuel treatment like Lucas or CRC to help the lubricity.

Sure is a lot easier to get fuel from the gas station instead of the airport, but you're not getting the lead for the valves.

If you don't over-treat with the fuel treatment, you'll probably save some money over Av gas too.
The Pe-150, 220 GPU uses low compression pistons and will run fine on regular pump gas. It doesn't need the high octane fuel required in high compression engines. However, there are several advantages of running 100 low lead aviation fuel. You can store aviation fuel for long periods without it going stale, it has lead which helps lubricate and it has higher octane.

The big disadvantage is the lead sometimes gums up the valve guides and the valve seats and will foul a plug. If you are going to leave a tank of gas in your boat unused for several months I would rather have 100 low lead. But if you use it all the time then regular gas is fine. The best solution is to run pump gas most of the time and fill up with a tank of aviation fuel once every other month.

If you need some good scientific data on the different fuels, try the EAA website. Even the aircraft that have an STC (Supplemental Type Certificate) allowing auto gas, will benefit from occasionally filling up with a tank of 100 low lead.
Around three years ago I had a new 0540 pump gas engine (flat top pistons) on order from Jurnigan, and I was excited about it so I called him one afternoon. We talked for probably close to 30 minutes (very nice man) and he told me the same thing. Even with an aircooled pump gas motor, try to run a tank-full of 100 LL through it every once in a while for the benefit of the valves.

I had a 470C I think, and I posted a link to chart on here somewhere that had most Continental engines info and a list showing what fuel was ok for each...I think mine was rated ok for pump gas....I ran it often in the winter and during the summer I ran av gas....

The old Skylane Cessna I used to fly had an STC for flying with autogas. It was the 470c series, 230 HP normally aspirated. Never missed a beat.

So I was wondering! Do you AC guys lean the carb on long cruises like I would on an airplane? :?
Climb-out to altitude is a bit more tricky in an airboat than an airplane. Probably not. I used to lean it out some when doing a lot of ground maneuvering to clean the plugs but then ya had to watch the temp.

Might be valuable to a frogger who does a lot of idling though.