Anyone ever had a nitro engine run backwards

[lgray88]

Not posted for a while on here, flying the helis has been pretty limited due to the lack of fuel and me not being out of the island for months now hasnt helped gettin a supply. But i managed a flight the other day, did everything as normal and started the heli and the engine was running backwards. Initially i thought i had put the blades on wrong, so i just stopped the engine and restarted it and all was fine. Has anyone ever seen this happen

[sacko]

Its a bit rich. Blip the throttle or lean it up a bit.

[trillian]

Yeah, I have an OS50Hyper that has done that a couple times. It was puzzling the first time and then I learned to recognise
the sound is a bit different, it idles lower etc.

[Spanner]

My OS50 used to do it quite regularly, always the first start of the day. Cut the engine and restart and was fine fro the rest of the session.

[lgray88]

Yes this is a os50 that this is happening too also, its the first time its happend so was just abit confused. Probably would of known about it if id attempted to take off.

[Si_B]

Funnily enough my Hyper 50 did this last night for the first time. Happens a lot on the planks, but never done that before on one of my heli's. Should have spotted it as the main gear was spinning. Never got to the point of actually trying to fly it though !!

[Randall]

happens all the time on plank engines, I even had it happen on a touch and go once where i clipped the prop on the ground, it made for a interesting event

[SRH990]

It seems to be a common thing with the OS50 Hyper when the weather is colder and it's running rich, I actually had mine cough in mid-air and start running backwards, engine screaming but no drive and a emergency auto! I've seen it happen with OS90's too, although not as common.

In the days when many engines had crankcases with a separate front that bolted on containing the carb and the front bearing it was possible to remove it and rotate 90 degrees, this gave you an engine that was almost as good running backwards as it had been forwards, useful for multi-engined planes, although not a usual heli application!

The original Heinseleit 90 heli used an OS90 with a special reverse rotation crankshaft as the engine needed to run 'backwards' for the mechanics, I think some Heim's were the same too.

[moonmanflyer]

Yep I have had it happen a couple of times

[trillian]

Funnily enough my Hyper 50 did this last night for the first time. Happens a lot on the planks, but never done that before on one of my heli's. Should have spotted it as the main gear was spinning. Never got to the point of actually trying to fly it though !!

The first time it happened on mine was last winter. It started and I carried the heli out, set it down, started to throttle up and the blades
were not turning. I walked over I could see the main gear turning and my first thought was the one-way bearing had gone
or something 'Very strange.

[richieclarkie]

I find that engines seem to be more likely to do this the more worn they are.

If it starts backwards what most of the guys I know do is pinch the fuel tube and lean the engine just till it's ready to stall, then let go and it often goes the right way. Otherwise stop it and start it again it's normally fine.

[Paulice]

Yep a few times, i just give a quick squeeze on the exhausts deflector and it runs the right way.

[del19_82]

I find that engines seem to be more likely to do this the more worn they are.

If it starts backwards what most of the guys I know do is pinch the fuel tube and lean the engine just till it's ready to stall, then let go and it often goes the right way..

This is what I normally do when it happens. I can't always catch it so needs the restart to fix it


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[marshdave]

yes we had one os50 that did this regular a restart usualy sorted it. just a warning i once fliked the prop on a 61 sc motor no glo start or radio switched on and it struck up always consider a glo 2 stoke live