ST .51
10-28-2006, 07:05 PM
#1
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Location: curitiba - paraná-----------, BRAZIL
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ST .51
Hello!
I´m trying to fly a Tutor II powered with a ST.51... My engine sometimes run very rich and sometimes very lean. I didn´t find the correct set-up. I used 10% nitro fuel with 20% oil; master airscrew 12x6 prop; uniflow tank and 19,5m lines.
Could someone help me?
I´m trying to fly a Tutor II powered with a ST.51... My engine sometimes run very rich and sometimes very lean. I didn´t find the correct set-up. I used 10% nitro fuel with 20% oil; master airscrew 12x6 prop; uniflow tank and 19,5m lines.
Could someone help me?
10-28-2006, 08:08 PM
#3
RE: ST .51
I had a problem with mine at first where it would be running very nicely in a 4 stroke in level flight but when I did any kind of manoeuvre it would break into a very lean 2 stroke and then take at least two level laps to come back to a 4 stroke. This was with zero nitro and 20% all castor fuel and a 12x5 Zinger wood prop. I tried many different mods to the engine (venturis, compressions etc) but nothing helped until one day I ran out of my usual fuel and happened to have some fuel with 25% castor so I gave it a flight on that. It completely transformed the engine and held a rock steady 4 stroke for the entire flight (and ever since 
).
The "problem" with mine was that it's so economical that it wasn't getting enough flow of oil with just the 20% so it overheated when under load like in a loop or whatever. The overheating forced it into a 2 stroke which made the overheating even worse. If this is the problem with yours then I'd suggest trying it without the cowl first and if it still changes tune then try more oil and maybe a bit less nitro.
). The "problem" with mine was that it's so economical that it wasn't getting enough flow of oil with just the 20% so it overheated when under load like in a loop or whatever. The overheating forced it into a 2 stroke which made the overheating even worse. If this is the problem with yours then I'd suggest trying it without the cowl first and if it still changes tune then try more oil and maybe a bit less nitro.
