We have a mono-wheel XS with a 912S and have had vapor lock on several
occasions,
on the ground and in the air. We solved the problem by putting some aluminized
heat mat on the underside of the carb bowls and fuel lines and fittings near
the carbs that are too small to be covered in fire sleeve. This protected
those parts from the heat of the rear exhaust headers.
Regards,
Terry Seaver
A135/N135TD
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Richard Lamprey
Sent: Wednesday, August 24, 2011 2:10 AM
Subject: Europa-List: Power loss, on taxi, vapour locking?
Greetings from Kenya, using the new modern approach of communication with the
forum
(thanks Ira!)
My Europa is classic, Rotax 912 UL, Warpdrive ground-adjusted prop. 550 hours
on the engine. The airfield altitude is 5500, the temperature was 28 C, so hot
and high but we are used to that.
Yesterday, I landed and back-tracked the runway, and on backtrack the engine
suddenly
lost power. Full power to expedite the backtrack, she ran very rough,
almost cutting out. Reducing on the throttle just gave me a smooth 3000 rpm,
enough to move slowly. Back at the hangar, I opened up the cowlings, ran a fuel
flow check, no problems, plenty of fuel pressure (200% of max requirements).
Cleaned the plugs (quite clean, nothing unusual). Checked for full deflection
of the throttle cable at both carb ends, no problem there. The vapour return
line was clear, so no problem there. I closed up, did full power run up,
no problems, flew for another 15 minutes without incident.
Could this be due to vapour lock in the fuel lines under the cowling? The fuel
lines from fuel pump back to carbs runs in fire-sleeve along the top right side
of the engine, but I think this is pretty standard. On the previous landing
I had to go around, so full power and she was running quite hot, but nothing
unusual. We use unleaded petrol (95 octane), and I have read somewhere that
in UK you should not use mogas above 6000 density altitude due to vapour locking
characteristics. So every takeoff we do here is above this altitude anyway.
Does anyone have an idea of what caused this?
Best
Richard
Classic 5Y-LRY
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