ORIGINAL: Hobbsy

Thanks Dan, I would like to have one for a Bruce Tharpe Super Plying King future project. Although I should finish my current Flying King for a Saito .80.

ORIGINAL: Hobbsy

Dan, is that the gasoline one or the real one? I guess I could look myself.

ORIGINAL: Old Fart

At more than a litre a flight you won't get many arguments here

ORIGINAL: Hobbsy

Jay, from what you're saying I gather that the .91 does not have an idle speed adjustment screw holding the barrel open. This is an .80 carb with the idle speed adjustment screw.

ORIGINAL: Jaybird


Made a discovery this morning. With the throttle lever off the barrel, it will travel from full open to full closed and not leave any gap. What does happen is that the end of the barrel where the step down is for the idle screw and lever mounting goes in past the edge of the carb body at full closed. I then mounted the lever all the way onto the step down in the full open position as it had been before. As I closed the throttle I found that the lever arm housing made contact with the carb body and that was what had been limiting the travel and not the slot and stud as I had thought. I repositioned the lever out away from the end of the barrel and it now travels from full open to full closed. I looked at another Saito carb and noticed that the end of barrel is flush with the carb body at full closed rather than indented like this one. I had swapped lever arms with another Saito 91 that I sent in for service so maybe there is a different design on the original one.

Mystery solved anyway.

Jaybird

ORIGINAL: Jaybird

Yes, it's a set screw that holds it on and with a gap behind it, it will work. The carb body is what it makes contact with in the fully closed position so it would either be that end of the aluminum body that would have to be filed or the back of the lever arm.

Thanks for the help!

Jaybird

ORIGINAL: SrTelemaster150


I advocate a combination of the methods. Limiting RPM while maximizing cylinder pressure W/short WOT bursts W/a rich needle setting.

Rings seat best under mderate cylinder pressure so some short busts of WOT best facilitate that. I do not bring revs up to max or stay @ WOT more than for a few seconds. I have used that method on air cooled motorcycle engines as well as water cooled automotive engines & of course my Saitos. The key is to maximize cylinder pressure while keeping stress (high RPM) to a minimum. Most of my Saito engines that are broken in thus develope HP levels @ or sligtly above Saito spec's. (if they are ever run on glow ignition to check power output, some are run on CDI from the start)

I do not ''peak'' the HSN mixture until there is some time on the engine as doing so would require maximum RPM.. So as far as the RPM levels during break-in we are (somewhat) in agreement.

ORIGINAL: AeroFinn


SrTele,

I'll be running in my rebuilt FA-125a this weekend:

What do you think about the fuel?

I'v been thinking of a a running-in mix of 20% castor + 10% nitro for the first 40 minutes ( 4 tanks or so) on very rich needle setting to keeps temps down & ensure very good lubrication & film strength

Then change of fuel to 17% good quality synthetic + 10% nitro and flying the model up in the air with needles still richer than normal for the first 4-5 tanks

Then setting the needles, both HS and LS to regular setting, i.e. from peak to -300-500rpm and LS to produce good transition (was it now such that with FA-125a you start with the LS needle flush with the lever?)


How does this sound?

ORIGINAL: Hobbsy

Actually, you can eliminate all the frustration by doing this,
10 minutes at 4,000 rpm at 1/4 to 1/3 throttle,
10 minutes at 5,000 rpm,
10 minutes at 6,000 rpm
10 minutes at 7,000 rpm

Shut down and refill tank,
Re-start, warm up, set HS needle at absolute peak,
Lean LS needle in 1/8th turn increments reducing throttle opening as engine idles faster from improved fuel mixture,
Check idle and transition after every other LS needle change, when you reach best idle and transition reduce peak rpm by 300 rpm rich. This will have taken up 40 to 50 minutes, go fly, your needle settings will change very little if at all from these settings.

The initial 10 minutes at 4,000 is for 10 minutes max, beyond that you are running the engine too slow and too cold to do any breaking in.
Using this regimen any Saito will hold compression like an ABC engine.

ORIGINAL: tacx

Hi All,

I purchased a used FA-100. I'm having trouble with the idle and need to know what the factory position for the needle is.

In the manual for this size engine it calls for ''the face of the screw to be FLUSH with the throttle arm housing''.

I know there are two type of throttle arms. One metal (which I have on my 220) and plastic which I have on this 100.

I have a note in my manual, that I jotted down awhile ago, that the needle should be 1/16'' IN from the surface of the plastic throttle arm housing.

Can someone verify which starting position is correct.

At the present time my low needle is 1/16'' in from the plastic arm surface. The engine starts fine and has good high speed, but the idle flucuates.

In other words, once started each time I go from high speed to low the idle seems to change and will not stay constant.

At this point I have....

1. Checked the valve adjustment. It's good.

2. removed the high needle and cleaned it.

3. Replaced the fuel lines to make sure there was no obstructions.

So I now think I need to concentrate on the low needle adjustment.

Two questions...

1. Can the low needle be removed like the high needle so I can clean and check for debris.

2. What is the proper position for the low needle screw head in relation to the PLASTIC throttle arm.

Thanks

Tom