blw

My Feedback: (3)

If you want to see exactly where the low speed needle phases out and the high speed needle controls the mixture, just set your low speed smoking rich and the high speed at peak (which is putting out almost no smoke). Advance the throttle and watch the smoke. It disappears when the throttle is about 80% open thru full throttle. As you reduce the throttle from WOT you will see the smoke begin to return as the low speed starts back in under about 80%.

_____________________________

The ultimate responsibility of pilots is to fulfill the dreams of the countless millions who can only stare skyward...and wish.

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Hobbsy

My Feedback: (102)

The main reason for setting the HS needle at peak is that the HS needle seat is fixed and it will not change. The only time the LS needle effects the HS needle is if you get the LS needle too lean. When the LS needle is too lean, richening the HS needle will not change anything.

skrez

My Feedback: (15)

Thank you gent`s for all your help with my engine problems, I will try tonight. I have been away from fuel airplanes for a few years, but after flying my 60 size Spit. with Saito engine last week I realized how much I enjoy it. It will take a little while to re-learn how to adjust my fuel engines.
Thanks,
Frank

FNQFLYER

why is it that people fiddle with mixture settings after every flight.  once i set the mixture settings at my flying field all other things being equal i very rarely alter things.  if i change a plug or a prop that s cause for checking the engine.  with the competition engines i set them at the field for the days conditions and then fly.  if at any time i have any doubt about rpm/power i use the tachometer and if the engine is within acceptable parameters = - 200 for sports flying =- 100 for cpmpetition then i leave them alone.  time spent setting the engine up from new or overhaul means more time flying less time fiddling.
sorry about the lack of capitals, it is operation day today so i am hunting and pecking on the keyboard

Hobbsy

My Feedback: (102)

I hate it when I read, (quote), I fiddled with both screws and there was no improvement, its amazing how often I've seen that over the years.

AeroFinn

Dave,

I first tried to set the LS needle of my FA-125a at HS needle tuned to peak. The engine behavied well but as I richened the HS needle the normal -300 rpm (full tank) for flying I was unable to get reliable idle below 2400-2500 rpm which is why I had to re-tune the LS needle. So I kept the HS needle at -300rpm and retuned the LS needle. I have now good transition and a reliable idle at about 2100 rpm. The engine also responds well to changes in HS needle: one click richer from the current tune drops the rpm by 150 rpm or so at full tank.

I know you a very experienced but I just want to say what happened in my case. I wonder why I was not succesfull with tuning the LS needle having the HS needle set at absolutely full peak.

I even tried to check the Saito manual but it did not explain the tuning procedure well..

Artto

Rudolph Hart

I've written something similar to that a while back when i was'nt getting on well with the airbleed carbys on the 30 and 182 twin.
Good luck with the op fnq.
Huk what type of 14x6 prop are you running on your 82?? with a slightly rich setting i'm getting 8800-9000 on the ground with a 14x6 apc.

Hobbsy

My Feedback: (102)

You have to remember that as the carb barrel closes the LS needle moves inward, so if it is a little too lean the inward motion will shut the fuel off. That's one explanation and I'm sure there are others, its not an exact science. Generally speaking.[8D]

FNQFLYER

with regards to wot / full peak,  unless the engine is inverted how can some one determine that the throttle that is carby opening.  the variable is the servo throw and moment arm on the carby.  i have had situations (with other peoples engines) where wot on the t/x gives anything from 7/8ths open to over travel on the barrel.  a lot of carbys and carby set ups are not linear, the best example being the YS63.  just another thought for some of you.  me i do my initial set ups in the test stand bt i am fiding more and more people who don't want to invest in that device and more to the point don't want to spend te time to set up the engine correctly.

SrTelemaster150

It's not hard to get WOT when setting up the servo. I always set up so that maximum servo throw has more than eniough to open/close the throttle arm on the crburetor. This can be determined by by observing the end of the trottle rod compared to the arm on the carburetor. (I always use a ball joint on the carburetor throttle arm) Then, just use EPA to limit the servot throw to prevent stalling the servo. You can varify WOT by manually pushing on the throttle arm to see if there is any more travel @ maximium servo throw.

FNQFLYER

yes to all of that but how many people follow a similar path?  what i was saying was the same in a different form and if one is having consistant problems that is a simple situation to eliminate

RC_Fanatic

My Feedback: (1)

I hate it when I fiddle with both screws and things get worse!

I'm used to 2-strokes like OS and Irvine that run in quickly so settings are soon stable. An engine that takes a couple of gallons of fuel to run in is new to me. But, as I have gathered from the experts here, patience is a virtue. With every quart of fuel, the stable idle gets lower and the idle needle slowly moves clockwise leaning out the idle and mid-range. Soon, I hope, I will fiddle with the needles and nothing will change.

Ernie Misner

And always, always, put your ear down to the airframe and make sure the servo is not stalled and buzzing at wot. Same with all channels...

Hobbsy

My Feedback: (102)

Once the engine has 40 minutes run time, just go for it and set the LS needle to its optimum setting and it won't change much from there.

FNQFLYER

reading all of the above i was reminded what my old mentor said the other day.
we were bought up on supre tigre and webra and enya engines.  twin needle valve carbies and long engine runs to bed in the rings etc so none of the above is anything new.
mind you the run in procedure for rossi racing engines still cause me wonderment mainly because it works.
for thos who don't know, you fit the basic recommende prop, a wooden one to the engine, start it and jam a steel rod into the prop arc, when the motor chews up the prop it is run in ready to race.  true fact and it usually took 2 props to achieve the desired result. the jarring to the hand meant it was advisable to use 2 people for this process, you helped your mate and he helped you. 

FNQFLYER

given all the features of modern radios, for example my 9503 has servo reversing, travel adjustment, sub trim and linear expotential and when you couple that with throttle curve like the heli boys then achieving the desired result is in one way simpler but is fraught with all that computer stuff that a lot of us avoid like the plague until we really have to use it. 
 

hsukaria

the throttle curve on my radio is great for my gas engine. I used 40% expo and the throttle feels really linear. I have not needed that on any glow engine.

Ernie Misner

That's butterfly carbs vs. barrel type for you.

FNQFLYER

you got that right, another function i like is servo speed, gives some interesting results in duration, but i leave that alone.
btb have you seen the mess you can make of an acto type a/c in heli mode, most amusing if you are just observing.

FNQFLYER

in case you were wondering i got bounced from my operation slot due to lack of beds.  appears as if the local indigenous indulged in fun and festivities which resulted in a number of them being admitted to the local hospital, tomorrow maybe but probably friday, just love our health system 

SrTelemaster150

Don't think ours is any better.

I've been waiting nearly a month to hear from a podiatrist that I was reffered tp by my Dr. It will probably be months after I hear from him to get an appointment. Meanwhile my knee replacment recovery is being jepordized because of foot related complications.

Rudolph Hart

Going back to servo throttle settings it does'nt matter if you don't get 'the full hole'@ full throttle,if the barrel is 7/8th's open you are already past what you will get re max rpm.

spaceworm

[quote]ORIGINAL: Ernie Misner


Better done with the engine NOT running![8D]

ejames7699

My Feedback: (18)

I have a Saito 100 I've had for years and have always had problem with muffler loosening up. I've use several types of thread lock with no success. Any tip would be greatly appreciated .

Hobbsy

My Feedback: (102)

The problem with Thread Loc is that the engine heat unlocks it. Teflon Plumbers tape is the thing that works. Two layers tightly wound around the pipe.