I'm sure its me, but I cant keep this thing running.This is reference to my YS fz-91.I bought it used here on RCU ,and bench ran it.It ran great on the bench,not so in the plane.After many changes and attempts with the fuel supply lines I am pretty sure I have it correct now.But it wont stay running.Goes from a lean sounding idle,when speeding up a little,it explodes power and quits.I checked the lines,klunk etc.I have read various reports of these engines being very tempermental,unfortunately I dont have the time to waist,been at this off/ on before Christmas.Any suggestions will be greatly appreciated.Already thought changing to another brand, but I like the power I think this will produce. Thanks

Did the instructions manual come with the engine when you bought it used? If not, you might want to get a hold of a copy from YSPerformance.com. Then read the manual carefully and double check all fuel lines. Make sure the check valve is in the correct line and is facing the right way. 99% of YS engine problems stem from the engine operator. None of my YS engines are temperamental. They can be temperamental if you don't know what you are doing.

Here are some basic instructions: [link]http://www.ysperformance.com/html/instructions.htm[/link]

Then read this page: [link]http://home.comcast.net/~mark.fuess/ys110.htm[/link]

bumpman....

....I set mine up as per instructions, and haven't touched it since. Set both
needles 1 1/2 turns out, regulator set flush. OS type F plug. I use PowerMaster
20/20 fuel with some added castor. Zinger 14-8 prop. I use fuel dots.

It runs better every lap....I love it.

FBD.

Thanks guys, those sites especially were helpful.I did not receive much with this engine only a pamphlet with engine breakdown on one side and a brief setup on the other.I will get back on it in a couple of days(I hope).I am using Cool power 15%,and a OS f plug, I think I read somewhere they (YS) recommended it.I tried Robarts fuel filler,and went to fuel dots,they seemed to do the trick for fuel lines.This is more than likely mis tuned by the previous owner.I believe I will have to start from scratch. I am not upset with YS,I also think they are exceptional or I wouldn't have bought it.I remember a old saying ignorance is bliss,but at 63 I'm not so sure. Thanks again John

Yes, it it best to set everything to factory settings, and that's 1.5 turns out for both the low end and the high speed needle valve, with the regulator flush with the casing as stated by Flyboy Dave above. Try Powermaster YS 20/20 instead of CP 15%. Also should you need to lean out the low end, then the low speed screw should be turned "counter clockwise".

Hi all,

I am the owner of a YS 140 DZ (I believe its DZ). I have it on the Hanger 9 Edge 540. I too have been having problems with the engine seeing that I bought it from a friend. I guess he had it overhauled or something from YS factory and it supposedley works now. My problem was that it would start up fine in idle then seemed to load up and stall when advancing to full throttle. I messed with low, high, and regulator settings for about 8 hours one day and still no luck. I brought it to the feild one day and some guy adjusted my "tapet" cleaerance for me and it seemed to run better, for the most part. After reading this forum, Im going to readjust everything back to facotry settings and go from there. Thanks....

Bumpman,


When all else fails, RTFM (Read The Manual)...

The Cool Power you are using contains an insufficient amount of oil (17% synthetic) and an insufficient amount of nitro.

YS engines need at least 20% of each, with 30% nitro 22% oil heli fuel recommended for best performance.

This better fuel may cost more than the 15% Cool Power, but your engine's reliability (and longevity) depend on it.

Just get the right fuel! No buts, no excuses.

great thread guys, thanks dave and Richard for their valuable input. I now own 2 YS 1.10's Both have yet to be run by me so I'm sure it will be a learning exp. I have read horror stories from people regarding YS's but I feel its user error most the time

Both links Richard provided have been saved for reference.

I think links like that should be saved onto a Sticky at the top of the page.

thanks

matt