2 Stroker engine outs

[DieselFan]

Thanks Morph and JY, you don't perhaps know the hours on the engines? I just want to see if there's some link between them? Like how the danger zone is 80-120 for pilot, what is for engines, statistically.

After seening the picture of the glass thingy JY, I don't think I actually have that one mine is shorter and more stocky if I remember. (Please no comments ). The plastics are shorter?

I've only ever witnessed one engine out, 503 on takeoff 50m towards powerlines hard bank left landed safely. Water. Hours 260ish.

[John Young]

I've only ever witnessed one engine out, 503 on takeoff

Hiya DF,

Why did the 503 have an engine out?

Apart from the numerous “glass thingie” engine outs (because several were multiple engine outs), I only know of the following: -

1. Windlass on X-country – pilot did not replace fuel cap. Pick-up pipe was lifted upwards and engine ran out of fuel with half a tank. Landed safely, replaced fuel cap and continued.

2. Aquilla 1 - silver top 582. Pilot did low pass over hanger to check solar panels. Engine lost power and forced a downwind landing. Ran out of runway and rolled trike across gravel road embankment. Pilot OK – trike “lotsa” rands. Expert advised that the silver tops with high hours have been known to suddenly lose power.

3. Flying along the beach at safe height. 582 Aquilla 1. Engine stopped. Pilot managed to restart on short final for the beach. Suspect carb icing.

4. Wrong spec. non-return valves fitted to a small 3-axis. Fuel reacted with O-rings and valves jammed shut. Engine cut and pilot landed safely in a field. Replaced valves (trip into town) and continued.

5. Ever-keen student in the circuit with his instructor. Low on fuel pushed for one more circuit, then another and EFATO – landed safely on the runway extension.

Regards
John ZU-CIB

[Flightstar]

Aquilla 503 at 340 hours. Landed safely back on runway. Suspected carb ice.

[Tailspin]

Engine out on touch and go while training. Winlass 503, slammed throttle open too quickly. Not sure of motor hours

[Morph]

Apart from the 503 Bush Baby seize I have not personally heard of engine-out's relating to the engine reliability and hours. The BB had an engine seize at 10 hours due to incorrect fuel/oil ratio (100to1 instead of 50to1 ). At that time it was not properly repaired and seized again without warning at 110 hours.

I personally believe that the 2-stroke is actually quite reliable. Obviously because it revs higher and hotter it needs more regular care but definately not the crack and bearing replacement at 300 hours. We have 503's running her in the Western Cape with over 1000 hours on the same crank. I cracked my old motor open at 540 hours and except for a decoke was well within specification. However if it has experienced any heat seize I would definately look at a complete rebuild because you don't know what damage was done. But this is true for a 4-stroke as well.

582's due to the fact of being water cooled have given problems around incorrect cooling due to bad radiator placement, incorrect collant/water ratio. I have also heard of a rotary valve failure.