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Jab runs on


Russ

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If the revs don't go up slightly, when you pull the mixture back to stop, that is telling you that you were running lean beforehand.

 

The theory is that before you stop you are normally running rich, as you pull the red knob you are leaning and the revs should go up, then fall as you pull further.

 

I usually run at about 1200rpm on the O320 Lycoming and pull the mixture until it gets rough, enrich slightly and get smooth, but lean running. Then pull to stop, That cleans the plugs nicely.

 

On my first run with the new motor I had roughness on one mag. I could see which plug was fouled by looking at EGTs, one was way down. That convinced me to always lean when on the ground. Lean seriously before take off and you will not risk a leaned take off as the engine will stop as you open the throttle.

 

Leaning before stopping should also prevent run on, but Jabs have Bing carbies, which are just a compromise.

 

 

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Gave the ol girl a good shampoo today, ( covered in bugs n dust from the other day )

 

Fired her up, went for a 30 min blat, oil temps up as before ( 36 day ) arriving back at the hanger, this time I shut off fuel supply and waited......she shut down perfect, so this seems to be my procedure, here on.

 

 

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As long as you don't leave the (engine) fuel pump diaphragm and carby 0-rings completely dry for long enough that they harden and crack, that should work a treat. There are replacement carby floats for Bing type 64 /94 carbies that will tolerate ethanol / the aromatics in 98, but they are stupidly expensive and extremely hard to get hold of. Minimising the immersion of standard Bing type 64/94 floats will probably give you an acceptable life for standard floats.

 

 

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You could Russ. Most of the non metallic parts are neoprene except the floats which are a bit suss in a bing carb of the CV type. The carbs that used to dry out and gaskets shrink are cardboard gasketted with leather accelerator pump washers. The diaphragm is not immersed in fuel in a bing.

 

Turning the fuel OFF in many aircraft is not standard so PLACARD the dash or the inevitable will happen. Some fuel taps don't fully seal and the engine will start and someone will take off and the engine will quit. Nev

 

 

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I've owned this 160 just on a yr now, now clocked up 170ish hrs, absolutely love it, have learnt that it handles shyte conditions just great, ( was alarming early in the piece, as I come from gyro world ) however now all's good.

 

Learning facts etc from you guys here has made " learning " enjoyable.......thanks.

 

( when allowable, a cert CAE is going straight in, then I'll be real happy )

 

 

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