Have an Enya 1.55 4-stroke with Cline regulator and on board glow driver. The engine is working well except for one problem. Often when I roll inverted the engine will miss just as I reach inverted position. It will keep on running inverted OK. Also if I push from inverted to upright level flight the engine dies just as I come over the top at full throttle. I suspect the cause may be related to fuel lines or tank, but have checked and all appear OK. Appreciate any suggestions.

TIA

I lost one after eating steak once. Could it be the position of the regulator in relation to the spaybar? It should be at the same level as the spray bar.

Sounds like a clunk line is getting hung up to me...the fuel line is "unporting" for a second.

A pump shouldn't care where the spray bar is located...that was the reason for the pump in the first place!

I thought this was a regulator? A regulator should be mounted as close to the spraybar level as possible. If not the pressure to the spraybar will vary by the length from it. If the regulator is mounted well below the engine then the engine will run richer inverted, if well to the side then it could lean out when making high speed rolls. Another term for pressure is head, it is typically measured in feet, a 200 foot water tower will have a pressure of 200 feet of water at the bottom. So if you mount a pressure regulator 2 inches below the carb it will have a pressure head of -2 inch's of fuel in normal flight, but +2 inch's of fuel when inverted. Since the Cline regulator supplies fuel at a lower pressure, it is may be more critical about placement than the Perry Pump.

Fellas,

Thanks for the replies.

The Cline is a regulator. It is mounted as per instructions within 1 inch of the carb, at about the same level. The tank clunk is located about 1/4" from the rear of the tank and is free to fall when inverted. The engine miss occurs just at the moment of reaching inverted flight, perhaps a second or so after starting the roll.

I wonder if it couldn't be a tad rich or lean and there is a "surge" as it goes inverted or upright. What throttle setting does this happen at? I'd imagine mid-to-low throttle.

If you hold the plane and put the nose up and down do you get this "miss"?

Just thinking...

Throttle is usually at mid to full. Haven't tried the nose up and down test, but it runs fine in a vertical climb before a stall turn.

I think the high needle is set about right. I peak it then back off a bit.

Thanks for thinking. Need all help can get.