The key to a good idle is you have to set it up at 2000rpm. This is the magic number for the idle mixture. Above 2000rpm the air bleed screw is not working and its working off the regulator. So if you have your normal idle at 2200-2400 which is a common number any changes you make on the idle mixture screw will not affect the engine much if at all. For this setting to be independant of the regulator you need to be at 2000rpm. Above 2000rpm the regulator and the air bleed are both working. So its impossible to tell which one is not set correctly. You will also notice that the majority of idle problems are also fuel related. low nitro fuels can be used but they make the settings more critical. Usually a guy that is running low nitro does so because he doesn't understand why he should be running at least 20% min for easy operation. And this same guy trying to run 15% nitro is also the guy that insists on adding castor oil to his fuel, and also doesn't understand how to set it the first place. So the combination of adding oil to the fuel dilutes the nitro, the less nitro the more critical settings become and the less experienced operator makes for a high percentage of guys having idle problems.

The YS engines are not difficult to setup they just work different than any other engine out there. This has the effect of making a guy that "thinks" he knows what he is doing not getting it to work right. It just works differently.

We are working on some Troy's tips pages that combine knowledge of many folks. This will likely help some folks. Its usually an operator thing. Also I find a high number of issue to be glow plug related. Idle will be the first thing to suffer if you have a plug that is a little fouled.

If setup properly the YS pressurized engines are the absolute best engines in the world for idle, and transition performance. There is not other 4 stroke engine on the market today that can idle as well and transition as clean as the YS. Oh and cube for cube the YS engines have the best top end power too. They are not engines for everyone. I will agree with that. However the lessons to learn with these engines are not difficult. The reason for this is the system they use. It is a learning curve that many struggle with.

Sorry bout that. I'm trying through this forum to help many with that.

Troy Newman
Team YS