YS 170 Troubles
 

I am having troubles getting my YS 170 to transition after the first flight/run of the day. On the first flight of the day the engine transitions great with no problems. The run up on the ground sounds great and it takes the throttle great on take off. But after the first flight of the day I begin to have problems, the engine won't transition. It starts to go lean and tries to spit the prop in the mid range. The enigine will idle for 1 min 30 sec. before it starts to load up a bit. Now I can get the engine to transition to full throttle by working the throttle stick and the engine is not lean nor rich on the high end. Only the mid range do I have problems. Now I have this problem after the first flight of the day on the run up on the ground and also on take off, it goes lean in the mid range but does advance to full throttle. Once in the air the problem goes away. No more transition problems in the mid range. Fuel: Cool Power 20%. Any help would be great.

Matt

RE: YS 170 Troubles
 

Hi Matt
sounds like the motor is running Hot
the 1.7 needs lots of cooling or it vaper locks.
One way to find out if this is the case,,check your motor after the first run if it continouse to get very hot on the ground after the flight
and becomes hard to start and sometimes transfers lean,, this is your problem.
take your cowling off < keep your glow driver off of the motor,>,, pull the fuel line going to the injector in back of the head and spin the prop till you get fuel coming out of the line ,,,this will displace the vaporand help coo the motor.
then the motor will run fine after you get fuel back in the line.
If this is what you are experiancing you don`t have enough cooling to the Motor
open the front cowling and exit holes.
If you have to, add foam around the cowling forcing the intake air around the Engine
this should fix your problem.

RE: YS 170 Troubles
 

The engine has this problem with or without the belly pan being on the airplane. Plus it is about 50 degrees where I am and after the engine runs in the air I can put my hand on it and hold it there without burning myself. The engine is in a Oxai Aries so there is plenty of air coming in and the exit is planty big as well. That was my first thought too.

Matt

RE: YS 170 Troubles
 

The overheat sounds a probable cause, make sure you have enough cooling on the engine.
One thing to check is, make sure the engine has smoke at half throttle, if it is not smoking then increase the pump pressure until you do, the engine is leaning too much and that causes the pre ignition that tends to throw the prop.
Running 30% nitro will make the engine run cooler as the nitro cause that, but you can use 20% no problem, but how much oil is in that 20% nitro fuel? it has to have no less than 20% oil, I run 30% nitro and 23% oil. Make sure you have appropriate fuel.

Try to provide more information to see if we can find what's going on.

RE: YS 170 Troubles
 

Fuel: Cool Power 20% Nitro 20% Oil. My other YS runs perfect on the fuel. The engine does not run hot it has a problem transitioning from idle to full throttle after the first flight on the ground. It sounds like it is rich not lean in the transition i.e. it loads up. Once your in the air the enigine runs fine doesn't die but when you land and taxi back it loads up at idle and dies rich. I have adjusted the pump as lean as it can be for the engine to run but it still loads up at idle on the ground, when it idles for an exteanded period of time.

Matt

RE: YS 170 Troubles
 

THen sound like you have a pump problem, the pump regulates transition and the idle on the 170, if you have played with the pump to the point where you can not lean it more, then you might have a problem with the pump plunger or plungers are not being able to close.

What about the smoke from the engine, how is it at idle mid anf full power?