best fuel mix for Ro Jett 65 on pipe? not sure on oil %. says rojett 08 on side of one lug and 065 on the other . Looks like Dub Jett and Rich Oliver signed on the bottom side. Came with Randy smith torque pipe(aluminum cone and stinger) , Set Pipe length to ? How big of tank ( for SV-11 ARC)

best fuel mix for Ro Jett 65 on pipe? not sure on oil %. says rojett 08 on side of one lug and 065 on the other . Looks like Dub Jett and Rich Oliver signed on the bottom side. Came with Randy smith torque pipe(aluminum cone and stinger) , Set Pipe length to ? How big of tank ( for SV-11 ARC)

   Try Powermaster 10/18 R/C sport fuel. Mine takes about 6.5 oz or so at sea level.

     Brett

Mine were happy on 10% nitro, 18% Ucon LB-625.  Pipe length was 17.5" to 18", but search on advice from Brett and follow it.

   Assuming it has the 140 or 144 degree exhaust, don't have a good setup for the 136 degree engines.

     Brett

I'm guessing that is will be a 136 degree engine (non-Brett Buck timing). The formula I posted is Dub's recommended brew - Excaliber fuels sells it as their "Ro-Jett" formula. Check Randy Smith's Tuned Pipe  chart posted on Heman's  "Aeromaniacs" site (and other places) for more info on pipe length vs RPM. 

Powermaster also used to sell a RO-Jett mix, but I don't know if the reborn company still does or not. Maybe! Steve

Someone please explain why RO-Jett requires some "magic" fuel?  I'm running both the 61 and 76 on good ol' SIG 10% nitro and 20% oil (1/2 and 1/2).  An ABC engine with BB, so why is it different?

Floyd

Someone please explain why RO-Jett requires some "magic" fuel?  I'm running both the 61 and 76 on good ol' SIG 10% nitro and 20% oil (1/2 and 1/2).  An ABC engine with BB, so why is it different?

Floyd

   It's not required and it's not magic.  I won the Nationals using Powermaster 15/18 (a four year old opened can, I might add) that you can buy at an R/Cist shop in the country.

     I like the RO-Jett fuel because it runs even more smoothly and doesn't have the tendency to varnish up. It has a much higher fraction of synthetic than the regular fuels like SIG. The RO-Jett fuel actually tends to remove some varnish, although  couldn't say that any mostly-synthetic fuel might not do the same. I ran it right before the 2007 Team Trials for about a gallon, and the engine stopped loading up entering the last corner of the hourglass, even after I switched back (because I ran out of RO-Jett fuel and switched back to 10/18). It recovered some lost power, too, and on one run David came up to me and said, after a flight "that engine didn't change 100 rpm for the whole flight".  Later on I kept using the 10/18 fuel, and after about a weekend of flying, the loading up started coming back. That's why.

     Varnish or carbon build up is a very real problem with ABC/AAC stunt engines. I would guess that most of the "worn-out" AAC engines are actually loss of power from varnishing. I opened up my engine for the first time in about 5 years and the inside looked like it had come straight out of a box yesterday - just a perfectly even exceptionally light copper-colored stain, no black spots or unevenness.

    We had all switched from SIG some time ago because of the extreme issues we had with plug "taters" that started killing power after as little as 10 flights and made you have to replace the plug after as little as 30-40 flights  The only issue with Powermaster in the past was that it was weaker than the corresponding SIG fuel. Not way off like Omega, Wildcat, Byron, but a little weaker (and ran longer).  No problem now, it's at least as strong as SIG. I had to switch back to my last can of the old stuff for the NWR this year, because I couldn't get through the flight on my tank on the new stuff, but that took care of itself as soon as it got warm enough to fly airplanes without a coat on.

   And as near as any of us can tell, it works about the same on a PA.

     Brett

We had one flyer at our field who had to de-varnish an OS (or was it a Brodak?)  Anyway, I'm aware of the castor oil varnish problem.  If I ever notice losing power, I'll remove the varnish, one way or the other.  However, I've been running ABC and ABN engines for many years using much the same fuel (1/2 castor, 1/2 synthetic), and I've yet had to de-varnish any engine.

F.C.

I have been using cool power fuel for the last year In my Rojett 65 with a header muffler. I ran some Powermaster "Mean and Green"10% THis weekend, I opened the needle up just a bit.