Saito 100 Idle problem

[voitty]

Hey Boys give me your thoughts on this. My Saito 100 has around 30 flights on it now it playing silly buggers. It normally idles for ever no problems and now it idles for 20 seconds and dies every time. I have tried low and high needle adjustments, fuel or air leaks (new tank and lines), falve clearances new plugs all with no results. What i did notice was it will idle no problem with the glow connected but dies shortly after removal. My fuel is 15% nitro and was wondering if my fuel may have lost some of its punch as it is around 2 months old. It did the same thing when I tried running it in on 5% nitro is this a possiblity and is it possible to test fuel nitro content?

[WangoTango]

What prop? Wood or APC? Diameter & pitch? Could be the fuel if it was air-contaminated. Do you have the copper washer installed under the plug?
WT

[crazyjoe]

I have run fuel thats over a year old no problem if properly stored. I run a 15x6 k series prop. I run nitro between 15 and 30% although it seams to like 30% the best. It sounds like your out of tune. Start engine and tune high end for max rpms then richen up 100 to 200 rpms. Now the low end turn the low end needle in a little at a time until the motor hesitates and or dies when advancing throttle. Then ritchen the low back up 1/8 of a turn . re tune high end as previosly described and you shuold be good to go.

[vmceachern]

I run 30 % nitro and have the mcdaniel on board glo system on the 170 Saito radial,no problems this thing is awesome on the great planes GeeBee.

[Unbalanced]

So for 30 flights, everything ran great, then on flight 31 you can't get a good idle? Did you change anything from flight 30 to 31? Maybe from a composite prop to wood? A lighter prop will reduce the flywheel effect.
Since it will stay lit with the igniter on, then I would say it is too rich or not enough nitro. My 125 runs 100% better on 30% then it does on 15%. I'd borrow a tank of someones 15% or more and try to re-tune the low end. Keep leaning the low end until it quits on transition, then richen slightly. If there is a stumble during transition, it's too rich.
After that, switch to your fuel and see if your engine acts any different.

good luck

[JimC-MD]

On those four strokes I have always let them warm up, set the upper end to just under max RPM and then pull down to idle. Then I would put the glow igniter back on. If the RPM picks up, the idle is too rich. I would adjust it in until when I pull the igniter off, I could not hear a change in RPM. Then just fly it.

There is one area that few people ever look at. Linkage and servo accuracy. If you have a servo that has a wide deadband then the fine idle control will be erratic. If there is slop in your linkage that has developed from vibration, it will make it hard to get that low tickover idle. I like direct linkage and ball sockets with a good quality servo. Many tend to put cheap servos on throttle and use z bends. This is a setup for failure IMO. I have fixed several of these types of complaints just by correcting linkage slop or replacing servos.

[rede2fly]

i have had a buttload of saitos and it to me sounds like it is too rich on the bottom. if the glow starter will let it run ,then you remove the glow starter,it is way to rich. what plugs are you using?? the 4 stroke motors need long reach plugs with NO idle bar. slowly turn in the low needle with the starter on it then remove the starter untill it will run by itself. this is a easy fix. also i would never run anything under 15% NITRO 30% coolpower heli is what saito reccomends. thats all i used in my saitos and never had any problems and tons of power but, its costly for that fuel

[steedav8ranger]

just change the stock plug out for an OS type F. the stock saito plugs go to crap after a few dozen runs.
easy fix.

i guarantee this is the problem if you have yet to change it.

[jamesrxx951]

has it been stored for awhile is that why the fuel is so old? if you try new fuel and totally readjust your carb and still needs the glow stick to idle i would have to say there would be a internal fuel leak causing rich conditon. you may just need a new set of carb seals. super easy to clean out and reseal carb. and the type f plug is supposed to be the best plug for the saito.

[voitty]

hey guys all is running fine and dandy now just got some fresh fuel and she is singing again. The fuel had drawn too much moisture in as the lid was not sealing properly, so simple hey.