Outside air temp

[GT280flyer]

What outside air temps do the two stroke guys start to preheat your gearboxes to prevent damage?

[t j]

Thats a good question. I've never thought about the temperature being too cold for the gear box.

It seems to lose something in the translation but anyhow the Rotax two stroke operator's manual http://www.rotax-aircraft-engines.co...kus/d04495.pdf lists the engine start/operating temperature as -13F to 120F.

[Av8r3400]

Just a thought....

You don't need to preheat snowmobiles. How would a 582 differ?

[t j]

Just a thought....

You don't need to preheat snowmobiles. How would a 582 differ?

The gear box.

[kmach]

Hi,

I used to have a Pelican Club UL that had a rotax 503 dual carb engine in it back in the 80's.

I flew that all winter, my temp cutoff for flying was around -20 C = - 5 F , I would preheat the engine compartment for an hour or so using an electric car heater, with a sleeping bag over the cowl. I would start preheating the engine at temps around 20 F , it made starts effortless ( no electric start) and gave the piece of mind that things were warmed up a bit for the start. Flew that setup for 350+ hrs with no problems .

[Jfquebec]

I think it's not a problem,,because the gear is always in oil not like piston in cylinder with a fine layer of oil,there it's a problem with cold....???And on rotax service .com he said you can put synthetic oil...better.....

Jf

[jiott]

Wouldn't the Rotax-Owner.com forum be a better place to get answers to questions like this? It is a very good forum IMHO.

Jim

[akflyer]

I have flown mine at -30 and the main issue is the oil being so thick you can hardly turn the prop. Mine has a clutch so its not an issue though. When I start the engine, it will warm up the gear box through thermal transfer. I always pull the prop trough a few turns to get the oil moved around the gears before I fire it up.

On my buddies without a clutch, I had to preheat the gear box at -15 so the starter could kick it over.

[GT280flyer]

Thanks for the replies, thought I had asked a fairly simple question hoping for some fairly simple answers. I run a hirth which some of you consider taboo, the owners manual doesn't show any temps like that and that is the reason I asked.

[akflyer]

Thanks for the replies, thought I had asked a fairly simple question hoping for some fairly simple answers. I run a hirth which some of you consider taboo, the owners manual doesn't show any temps like that and that is the reason I asked.

I dont think you can really do any damage to it from starting at cold temps. As I said above, the worst thing will be the oil so thick your starter wont want to turn it over. As long as the engine will start, your not going to hurt the gear box. I would let it warm up real good though and the thermal transfer from the engine will have it warmed up pretty quick. Robing power from you trying to turn the gears in the cold thick oil is about the worst side affect I can see.