Yak13

My Feedback: (17)

I have a "new" OS .61 FSR running on an Atlas with pipe.I usually run it with 15% Nitro, but a few days ago I got some 10% borrowed (forgot my can). Performance was noticeably decreased. I want to ask if raising the nitro to 20% will similarly improve performance over the 15%.

The plane flies beautifully and fast, but a little more speed sounds like an interesting idea!!!

Thanks all for your advice.

Ed

TFF

It will make it go faster, but also will make the life of the engine to go faster. I would stay with a max of 15%

alan0899

G'day Ed,
I had an OS 61 FSR ABC, It's worn out now, bought it in 1982, ran it on 0% nitro, FAI fuel, because nitro was $38.00 a litre back then,
It ran perfectly, because it was designed for 0% nitro fuel, so be very careful how much nitro you use, it could, as was stated, make the life of the engine go faster.

Cheers

jeffie8696

Iwould call Merlin Plugs and ask Aldon what he suggests.

jrlingrel

I have been running Gold Head 61 FSRs for years, never ran more than 10% and engine life has never been an issue.

John

Sport_Pilot

20% fuel will not shorten the life of the engine, at least not enough to be noticed.  Just run it dry and you will be fine.  Experment with cooler plugs as this will further improve performance, and prevent detonation which would shorten the life of the engine.  OS engines sold in the US are set up for about 15% nitro but higher percentages can be used if cooler glow plugs are used.

jeffie8696

Ihave been playing around with the benefits of colder plugs for a while and on a high quality engine it can make a big difference. Longer plug life, increased fuel mileage and more power, assuming proper tuning.

Yak13

My Feedback: (17)

Thanks guys. I will try it with a cooler plug. I've been flying pattern 61s forever with FAI to 15%, but it's about time to try the 20.
Thanks!
Ed