4 Stroke high speed needle setting.
 

Forgive me..but I need to confirm something.

With a 2stroke, I have no problem setting the high speed needle.

But this same procedure could cause problems on a 4-stroke.

If I lean to max RPM then back off to slightly rich, I stand the risk of detonation BIG TIME.

And if I use RPM, I can richen it up to whatever I want (if the prop isn't loading the engine enough).

Right now, I'm not sure if my YS 110 is going to be happy with a Master Airscrew 3-blade 14x7 prop.

I can richen it to @9300-9500...but she is really rich.(Tons of smoke and a gurggle break at high rpm)
good for break in...but I don't think she is going to be very happy.

otherwise It seems to overspin that prop to 10,500.
I risk floating a valve at that RPM.

Is it too lean?...well that's my problem..I just can't tell straight away.

What should I look for to make sure she is happy, and not leaned too far?

This is my first 4-stroke..but I'm a fast learner.

What I've read says to richen it to @ 500 rpm off peak RPM.

RE: 4 Stroke high speed needle setting.
 

you shouldn't be using the mixture control to adjust max rpm. instead, get the correct prop that allows it to run at the optimum rpm, and back off from there. 10.5k does seem high for that size engine, although that is just a guess...

RE: 4 Stroke high speed needle setting.
 

It seems that MA 14x7 3-blade is too small for the YS 110. You might want to try Graupner 14x7 3-blade, which has wider blades and thus puts more load on the engine.

The YS 110 is happiest between 9300 and 9500 rpm. This is where the engine develops the most power. I usually richen mine 300-400 rpm off peak.

RE: 4 Stroke high speed needle setting.
 

choose a larger prop. One that will stay below 10000 rpm when leaned out. Then adjust mixture to the rich side of max rpm, and you will be OK.
You have to stay clear of valve float rpm when in flight, and it has to be done with the prop load, not with overly rich mixtures.

RE: 4 Stroke high speed needle setting.
 

I just ordered a couple 14X9 3-blade props.

I will have to check out the graupners...

What have you gotten with the 14x9's??

Larry

RE: 4 Stroke high speed needle setting.
 

I believe the 14x9 3-blade will be slightly too big unless you have a really strong 110. I tried that prop on one of my 110's and only got up to 9K rpm.

RE: 4 Stroke high speed needle setting.
 

It's too bad Master Airscrew doesn't make a 14x8 3-blade prop because that prop would have been perfect for the YS 110.

RE: 4 Stroke high speed needle setting.
 

As I am performing the RPM check on the ground....I would think a reading of @9000 on the ground with a 14X9 would be about right when it unloads in the air.

Before I order a couple Graupner 14X7's do you have a tach reading?

I really don't need more 14X7's if they won't load up my 110 properly.

I am running an OS "F" plug and fuel is Powermaster YS 20/20

If the 14X9 loads too much I could always go to 30% Heli fuel as long as it has 20% oil content.

RE: 4 Stroke high speed needle setting.
 

The problem may be with the MAS props. One of the engine columnists opined recently that on a pitch gauge MAS props all checked one inch flatter in pitch than they were marked; a 14x7 was actually a 14x6. This accounted for his slightly higher RPM with the MAS, NOT superior design or materials. Jim

RE: 4 Stroke high speed needle setting.
 

9K rpm was peak rpm on the ground, so that would be roughly 8600 rpm richened down. To me, 8600 rpm means too much load on the engine.

Sorry, I don't have a tach reading for the Graupner 14x7 3-blade. Based on experience with Graupner 2-blade props, I am 99% certain that the Graupner 14x7 3-blade would load the engine more than the MA 14x7 3-blade. You might want to order just one to test it out.

RE: 4 Stroke high speed needle setting.
 

Ahhh..after richening it was 8600....
What about 30% Heli fuel..that should help some?

I ordered 3 Graupners 14X7...Hell Shipping as as much as the props.....I REALLY WANT TO MAIDEN my Miss America Saturday!

RE: 4 Stroke high speed needle setting.
 

My 110's run best on Powermaster YS 20/20 with great fuel economy, so I don't think I will be trying 30% anytime soon.

You ordered your props from Hobby-Lobby? I didn't pay as much for shipping when I bought my 2-bladers from there.

RE: 4 Stroke high speed needle setting.
 

Yeah...But I needed them for Saturday.......

Larry