Sender: <marv@lancaironline.net> (Marvin Kaye)
To: flyrotary
Date: Wed, 30 Jul 2003 21:37:06 -0400
Message-ID: <redirect-2507719@logan.com>
From: Mark Steitle <msteitle@mail.utexas.edu>
Subject: Re: [FlyRotary] Re: auto troubleshooting question
In-Reply-To: <list-2507275@logan.com>
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At 09:02 AM 7/30/2003 -0700, you wrote:

>--- Fly Bum <fly_it_slow@yahoo.com> wrote:
> > Trying to help a friend get his recently purchased
> > 2nd
> > gen running.  He has a street ported 13b with a
> > weber
> > copy side draft carb.  The engine starts and runs
> > fine
> > for about 3 minutes and then it starts
> > backfiring/popping (a little) and loses power and
> > quits.  Let it sit for a while and it will start
> > back
> > up and run ok again for another 3 minutes.
> >
> > I don't think it's the fuel pump cutting out since
> > he
> > has it hardwired on and it seems to be putting out
> > plenty of flow.
> >
> > What else to look for?
> >
> > Thanks guys!
> >
> > Joa
> >
> >
>Sounds like fuel starvation. If he is using old fuel
>line hoses, sometimes they will crack on the inside
>and under pressure the cracks will partially close off
>the line.
>                       John
Joa,
While not a Mazda "expert" myself, I second the fuel starvation 
diagnosis.  However, I would disassemble the carb and check it out closely, 
or rebuild it.  I suspect it has been sitting for a while and the needle & 
seat, and possibly the jets are gummed up from old gas.  I have this 
problem all the time with my boat's carburetor after sitting all winter.

Mark S.