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                           RV4-List Digest Archive
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                     Total Messages Posted Mon 10/20/03: 3
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Today's Message Index:
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     1. 09:47 AM - Re: RV4-List Digest: 1 Msgs - 10/19/03  (Steve Mullins)
     2. 07:12 PM - Re;Auto Fuel in O-290 Engine  (Oldsfolks@aol.com)
     3. 07:43 PM - Re: Re: RV4-List Digest: 1 Msgs - 10/19/03  (Ross Scroggs)
 
 
 
________________________________  Message 1  _____________________________________


Time: 09:47:02 AM PST US
From: "Steve Mullins" <smullins@drury.edu>
Subject: RV4-List: RE: RV4-List Digest: 1 Msgs - 10/19/03

--> RV4-List message posted by: "Steve Mullins" <smullins@drury.edu>

Hello all,

I am in desperate need of advice. I have been running auto fuel in my 0-290
powered 4 for three years with no problems until recently. Fuel pressure
starts to fluctuate and drop once temps come up. I switch back to avgas tank
and things return to normal. Is this likely vapor lock? Are there other auto
gas issues I need to be aware of? Prior to this recent development, the
engine runs just as good with either fuel.






________________________________  Message 2  _____________________________________


Time: 07:12:30 PM PST US
From: Oldsfolks@aol.com
Subject: RV4-List: Re;Auto Fuel in O-290 Engine

--> RV4-List message posted by: Oldsfolks@aol.com

It sounds as though you may be getting mogas with some alcohol or propane 
added. 
Do you test the mogas for alcohol? I use a small bottle with a marked amount 
of water/ then fill with the mogas and shake it up. After it sits for awhile 
the water will show slightly more if there is alcohol present. If the water 
level is the same,no alcohol.
I have used mogas for years with 20-25% 100 LL mixed in to give me leaded 
gas. I have had no problems that I hadn't had with straight 100 LL.  If the plane

sits in the sun and the fuel gets hot you'll have vapor-lock. That's why you 
have an electric aux. fuel pump.
My opinion,for what it's worth,


Bob Olds A&P , EAA Tech. Counselor
RV-4 , N1191X , Flying Now
Charleston, Arkansas
"Real Aviators Fly Taildraggers"






________________________________  Message 3  _____________________________________


Time: 07:43:15 PM PST US
From: "Ross Scroggs" <rscroggs@comcast.net>
Subject: Re: RV4-List: RE: RV4-List Digest: 1 Msgs - 10/19/03

--> RV4-List message posted by: "Ross Scroggs" <rscroggs@comcast.net>

Steve,
  Is it possible that the tank with the auto fuel has it's fuel tank vent
partially plugged?  That
could be the reason for the drop in fuel pressure.  In flight, while running
on auto fuel, watch for
any change in the appearance of the tank skins compared to the tank with
100LL.  The auto
fuel tank may be getting sucked in which may be visible.
   Do you have sloshing compound in your tanks?  If so, it could be
releasing and plugging up
the tank pickup.

Good luck,

Ross Scroggs
RV-4-#3911 Wings

----- Original Message ----- 
From: "Steve Mullins" <smullins@drury.edu>
Subject: RV4-List: RE: RV4-List Digest: 1 Msgs - 10/19/03


> --> RV4-List message posted by: "Steve Mullins" <smullins@drury.edu>
>
> Hello all,
>
> I am in desperate need of advice. I have been running auto fuel in my
0-290
> powered 4 for three years with no problems until recently. Fuel pressure
> starts to fluctuate and drop once temps come up. I switch back to avgas
tank
> and things return to normal. Is this likely vapor lock? Are there other
auto
> gas issues I need to be aware of? Prior to this recent development, the
> engine runs just as good with either fuel.
>
>