My first gallon was YS 20/20 fuel. The idle was in the 3000 range - fast but manageable meaning run after the Mayhem and grab its tail. Others have said that 5%, 10% or 15% run fine in their YS's. Motorman37, do you really know for a fact that the YS 110 won't idle on 15%? It does not sound logical to me. Higher nitro will allow the engine to idle without dying. Mine does not go below 4000rpm.

I did some reading last night from someone who services YS. My understanding is that the regulator will turn off the pressurized fuel feed at low speed. The fuel feed beccomes suction like a regular engine. No fuel should come out if I disconnect the line at idle. As a matter of fact, mine squirts fuel out.

I started to take the regulator apart to take a look. The membrane appeared to have a permanent bow in the inward direction. Other than that it flexed fine when I turned the engine over. I did not find but very very little trash inside. I ran out of time as I was called in to work. I believe my regulator is not turning off as it should to switch the fuel feed from pressurized to suction.