rdcntrl1

good mornin all
i have a (ys f-120) & i spewes oil all inside my fuse??
i have filled all holes in my firewall but is this engine always this messy ??
thnx
rdcntrl1

jetmech05

is there a crank case vent on this engine? If so connect some fuel line to it and route that line overboard, if you haven't done so

JohnBuckner

My Feedback: (1)

There are no crankcase vents on YS engines. Are you sure your plumbing system is not leaking. Fuel tanks for all YS engines are pressurized when running and for a considerable period after stopping. If you are using a conventional bung type fuel tank make absolutely sure that the seal is tight. Hayes 'O' ring type tanks are a better bet for YS engines. Also its best to wrap the tanks with a filament tape to minimise bulging.

John

Gray Beard

My Feedback: (-1)

First off there is a YS forum in the glow engine forum with answers to most any question you may have about these engines. A lot of information. If you have sprung a leak in any of the lines or have a bung problem it is easy to spot right after landing/running. If you don't get pressure from your pressure line it's a dead give away. If anything the YS is a cleaner running engine then any of the other four strokes. If you are getting fuel splashing out of the carb then your not tuned correctly. All these things are covered in the YS forum. The YS pumps about 7 pounds of pressure into the fuel tank so as John pointed out, any hole or loose bung will squirt fuel.

ChuckW

Agreed. You will get some oil out of the exhaust but that's it.

rdcntrl1

thnx for all the answers, & i am also some what new to rcu! im still learning the site!but thnx , i was woundering is there a front crank seal ?? maybe , just a thought , the bottom of the engine is all wet from the prop back as far as it can go ??
thnx again
rdcntrl1

aka jeff

ChuckW

Number 41 on the list:

http://www.centralhobbies.com/Engine...YS120FZEX.html

Gray Beard

My Feedback: (-1)

That oil can also be just from an over rich tune. If your too rich you can get fuel bouncing out the carb and when it hits the prop wash it can be blown down and back so it looks like it is flowing from the front of the crank. I horse trade for my engines so all of them are for the most part used.
When I get one I first check and replace the diaphragm and gasket. I hook up the fuel system to an old fuel tank and roll the engine over while I'm holding it to make sure it's pumping fuel. I set the regulator flush with the case, this is the factory setting. Then I adjust the valves, set it up on a starting stand and fire it up. I check it out completely as it's running for leaks then I start doing the tune up. Now this engine is ready to go into a plane. As I fly the plane I do minor tunes after it's landed. Once I have the needle and regulator set I pretty much don't touch them again unless the weather changes {a lot!} or I change prop sizes. Come the winter I know I will have to fatten up the needle valve as the weather gets colder. I end up about 4 clicks fat from summer to winter. This time of year I start leaning my engine up again. I do this with both my YS and OS four stroke engines. Go into the YS engine support and look around. Everything you need to know is already there.

rdcntrl1

thnx guys ,

ChuckW

Same here here. I also go through and try to figure out everything the previous owner did so I can undo it. It is amazing how many people struggle with these engines and try all sorts of voo-doo recommended to them by some "expert" when all they had to do was plumb the thing right in the first place.

Gray Beard

My Feedback: (-1)

It does amaze me as to how many YS pros there are at any field I fly at, yet, I'm the only one I see using them??? That's one reason I am able to pick them up for nothing so I never say much to anyone about them. I don't recall ever having to teach anyone how to tune/adjust one either. Sport pilots have heard how hard they are to tune, how tempermental they are, how they must have high nitro fuel, on and on and on. With all these experts where are all the engines??? I find them easier to set up and tune then even my OS engines. I love the ease of never having to worry about tank location. All the added power is just a plus for me. If people would just keep from twisting the regulator screw if they are having a problem all would be well. Maybe if they read up and figured out what that screw did they wouldn't be twisting it all the time.

rdcntrl1

ys 120sf ,
im still reading & tryin to learn , love the sound of this engine, just wanna get the leakin to stop,imma take the cowl off & check all hoses & tank stopper in the mornin,
thnx guys
ps, the box says part #ys0070

Gray Beard

My Feedback: (-1)

I have a new one under the bench still in the box, 0070 is the number on my 1.20F model. Great thing about YS is they sound really cool with just a header system on it. I broke a header and lost it and my muffler on one, I had some old header systems someone had made and given to me so I tried one out on my FZ model. Works and sounds great. I have also run headers with long deflectors on pumped OS four strokes. With the long deflector it really changes the sound.