I have been fortunate enough to have someone give me a Great Planes Super Sportster 60. Complete with TX, RX, batts. and engine. I still can't beleive it....

The Engine is an (apparently very dependant) Tiger something something.. .60. The owner was burning 15% (I think that means 15% nitro) fuel in it. I burn 10% in my Nexstars OS/FX .46
Is it OK to use 10% in the ol' Tigre. The reason I ask is that I remember reading something somewhere that said that you should never change the type of fuel you burn in an engine.

Is this just an Urban Legend?

Thanks in advance for your help,

Yep, urban legend. Some engines prefer a certain brand/nitro content then others. You will have to retune the engine slightly for the lower nitro content. If you want to once you change fuel, replace the glow plug.

On the certain brand/nitro content as example is my OS91 Surpass II. Our LHS changed to S&W fuel. I had been running Byrons since day one on this engine. I bought a gallon of the S&W with the same nitro/oil content and found that I seriously needed to richen the engine and the needles became really touchy, meaning a click or 2 each way made huge differences but power was no different. I have now switched back to the Byrons and the engine is right back to the way it was before.

Another one is YS Engines. They love 20% nitro 20% oil (20/20) and I started out on the Wildcat. I switched to 30/24 Cool Power and all was well with gobs more power but then these engines love high nitro content.

Your new engine will love 10% nitro.

Your engine is probably either a Super Tigre, or a Thunder Tiger. If it's a Thunder Tiger, it could be either a GP or a Pro version (both are ABN types). If it's a Super Tigre, it could be either a ringed or ABC type.

In any case they will all run perfectly well on the 10% fuel.

Oops, double post

i agree with what britbrat said[sm=biggrin.gif]

Looks like that dumb britbrat said it twice [&o]

great to have level headed people in the plane forums! post this over in the rc car area and you will have people telling you that you have to rebuild your engine if you plan on switching BRANDS of fuel, nevermind nitro/oil content!

yeah, as someone else mentioned, it will be fine. dump it in and go flying!

I would say go the other way, change the Nexstar up to 15%, it likes it...i went from 10-15 in mine and it runs SO much better....amazingly it turns more rpm, but i can keep it a little bit richer, so the temps stay the same, its sweet...

Thank you all for your input. I checked and it a super tigre..(don't know yet if its ringed or not)

How about running 30% in a Super Tigre GS-40? I was lead into this by a well seasoned flyer. The 40 runs strong but, it sounds like it's under water (if that makes sense). The other 2 strokes at the field have an even buzz sound. My kinda bubbles? I do have it running rich. I thought I'd try and lean it out some and it quit running on a throttle up after a touch and go. So, I riched it up again. I was going to try the 10% or 15% the next trip out. Just see. I just started flying my second plane. It's a Big Stick with an OS FS 90. That runs "sweet" on the 30%.

What you are probably hearing is detonation and will destroy the engine quite quickly, it may not happen suddenly but it will happen.