Nice tater

I have seen the exact color of takers is it nitro of oil or alcohol I do not know. Why do they happen ? I have ran hundreds of flight and not had one then they just happen. I almost think it late timing plug gets week and they show up. Mystery to me.

   I don't know for sure, but we had them incessantly when we were running the PA61 on SIG fuel. Switched to Powermaster, absolutely nothing since about 2000. Randy says it is something in the oil, which might be true, but the one thing we found out about it is that they formed much faster if you put any sort of anti-foaming agent (e.g. Armour-All or some other silicone oil) in the fuel. The solution was obvious, don't use SIG. We later briefly tried SIG Syn-Power, nothing, which supports the castor oil theory.

     I ran SIG in the RO-Jett for maybe 50 flights, and didn't have any issue with taters. It didn't have any useful effect on the few problems I was having with the engine, I switched back to Powermaster right before the 2003 NATs, no issue since and no taters or glow plug issues, aside from one blown element from debris.

   When running SIG, individual engines varied in how quickly they formed. One engine I ran for a while, Bill Fitzgerald's PA61, would go maybe 15 flights on a plug. I put the engine in right before the 1999 Team Trials in place of the 40VF, and I was really disappointed about the lack of power, it was far less solid with the 61 than the 40VF. Finally we inspected the plug, you almost couldn't see the element. Replaced the plug and it practically dislocated my shoulder. But in 10 flights, it started fading. David's first engine would go maybe 40-50 flights, even set up absolutely the same way. We never had any problem with this on smaller engines, just the 61/65, presumably because the internal temperatures were much higher.

       Brett