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Engine basics => Engine set up tips => Topic started by: Brad Smith on April 27, 2014, 07:58:48 PM

Title: Rich upside down
Post by: Brad Smith on April 27, 2014, 07:58:48 PM
I have a SV11 with a double star 60 clunk tank uniflow like John Miller sets them up. It goes rich upside down can i just turn the pickup tube up or do i have to move the tank up?
Title: Re: Rich upside down
Post by: Andrew Hathaway on April 27, 2014, 08:04:22 PM
Should be able to cure it by raising the uniflow vent inside the tank.
Title: Re: Rich upside down
Post by: EddyR on April 28, 2014, 06:12:47 AM
With the plane sitting on the ground move the uniflow vent up y1. Do not connect the uniflow to the pick up line use a separate hard tube.The uniflow tube does not need to go all the way to the back,half way is OK n1
 

I changed it to up. My mistake. ~^ ~^ ~^ ~^ ~^ ~^ ~^ ~^ ~^ ~^ ~^ ~^ ~^ ~^ ~^ ~^ ~^
Title: Re: Rich upside down
Post by: Brad Smith on April 28, 2014, 06:55:26 AM
EddyR the tank is plumbed the way you describe so move the uniflow down i will try that.
Title: Re: Rich upside down
Post by: Brett Buck on April 28, 2014, 08:44:30 AM
EddyR the tank is plumbed the way you describe so move the uniflow down i will try that.

    If you are running rich inverted, you want to move the uniflow vent UP (toward the top of the tank with it sitting on the ground) not down. Moving the vent is the same as moving the whole tank.

     Brett
Title: Re: Rich upside down
Post by: Brad Smith on April 28, 2014, 10:48:59 AM
I had the uniflow vent in the middle so how far should i turn it .
Title: Re: Rich upside down
Post by: Brett Buck on April 28, 2014, 02:49:31 PM
I had the uniflow vent in the middle so how far should i turn it .

  How much faster is it upright VS inverted?

    Brett
Title: Re: Rich upside down
Post by: Brad Smith on April 28, 2014, 02:53:03 PM
Upright it does a nice 4 2 break inverted it goes rich a good bit by the way the motor is a double star 60 side exhaust.
Title: Re: Rich upside down
Post by: Balsa Butcher on April 28, 2014, 08:53:06 PM
It's a trial and error thing. Move it up about 1/8" and go fly. Re-adjust up or down until you get the run you are looking for. 8)
Title: Re: Rich upside down
Post by: Brian Hampton on April 28, 2014, 09:19:35 PM
Coincidentally (because it was also with an SV-11) I had the exact same problem after I'd done some maintenance removing engine and tank because I'd inadvertently moved the uniflow line at some point. In my case I had to raise the end of the line about 3/8-1/2" (by trial and error) but I'm not using muffler pressure. With muffler pressure the amount needed would have been much less.
Title: Re: Rich upside down
Post by: Brett Buck on April 28, 2014, 09:59:52 PM
Upright it does a nice 4 2 break inverted it goes rich a good bit by the way the motor is a double star 60 side exhaust.

     Pete is right, just try 1/16 or 1/8 and see what happens. We routinely shim in 1/32 increments but that's a relatively small change.

    Brett