YS91 idle settings

[Alfred]

Stratus
YS91
Hatory 937
Enya #3
20% Nitro
20% synthetic

The engine isn't fully run in yet (about 8 tanks so far)
It might be a bit too early to be sure yet, but it seems to show the same characteristics that my YS61ST-2 always had.

I was able to achieve a nice reliable idle with great tick over by leaning the bottom mixture a bit when it then showed me the same old bad tendency that the YS61 always had.
Which is that the engine will "hang on" at the bottom when the throttle hold is applied.
So I richened the bottom up to the point where I have to blib the throttle for it to transition up.
That's very very rich as can be seen on the amount of fuel it uses in idle and how rough the idle is.

Otherwise the engine is 100% reliable.
As this is my 2nd YS engine which exhibits the same symptoms, I have to wonder if it is the characteristics of the YS engines?
My OS 70 and the TT50 engine idle perfect and will drop back to idle instantly.
Any thoughts?

[tnreefguy]

What kind of fuel are you using. Mine did that until I switched over to coolpower.

[Alfred]

Mine is Klotz198 synthetic oil.
I have got 20 litre of pre-mixed fuel left.
Once that is finished I will switch over to coolpower permantly.

[tnreefguy]

That might be some of the problem. Keep us posted when you do switch over.

[Gary O]

I've been mixing my fuel for a couple of years now and I use that same oil. I run 30% nitro, 20% of the KL-198, and then I also use the Klotz Uplon Fuel Lube at 2 ounces per gallon. I run both OS and YS engines and I've never had a problem with either one. All YS engines are very sensitive to low end needle adjustments. I would be willing to say that if you were running 30% nitro that alone would change it somewhat.

[david.read]

Alfred,

I have found that if the HOLD % is slightly too high. (i.e. higher than the idle) the engine seems to stay on to the pipe when hold is selected, and give it the ding,ding ding note :)

This post is quite old now so i'm sure you have sorted it out. But if you lower the hold point to just above the idle then i would be confiden't that will fix it.

It worked for me..

Regards,

David Read :)

[Alfred]

David
I haven't had another chance to autorotate the Stratus again since my last post as I have found a field closer to my place, but the grass is too high to risk an auto.
I am going to mow a small square in it tomorrow and will hopefully this weekend get a chance to give the Stratus a go on another auto.
The engine hasn't quite run it yet, so achieving a low idle setting is still a bit touchy.
So your advice is not outdated and I will cerainly try this approach.
Thanks for the suggestion, I will let you know how I go over the next couple of weeks.
:D