Am i right?

[Helgesen]

I suspect my Caliber 30 with OS MAX SX 32 to be running a little to lean.
- The reason for my suspition is that the idle is kinda sluggish and sometimes it stops when I move it away from the pitstop to start flying.
- The heli does not use that much fuel compare to other similar helis.
- The engine is quite hot and it looses some power after 30 minutes with hoovering (on and off that is)
- There is some smoke, but not much and there is no oil/fuel drop from the muffler.

Should I turn the needle a turn or two?

I am quite new at fuel heli, so I am at the hoovering stage (still on the first can of fuel)

[vlam67]

Originally Posted by Helgesen

I suspect my Caliber 30 with OS MAX SX 32 to be running a little to lean.
- The reason for my suspition is that the idle is kinda sluggish and sometimes it stops when I move it away from the pitstop to start flying.
- The heli does not use that much fuel compare to other similar helis.
- The engine is quite hot and it looses some power after 30 minutes with hoovering (on and off that is)
- There is some smoke, but not much and there is no oil/fuel drop from the muffler.

Should I turn the needle a turn or two?

I am quite new at fuel heli, so I am at the hoovering stage (still on the first can of fuel)

Hi Helgesen,

I don't know the particulars of your heli, but I know Internal Combustion engines run hot when the mixture is lean. I reckon that it gets hot and loose power because the mixture is lean and not enough oil in the fuel mix so friction in the piston and cylinder is increased. Add a bit more oil to the mixture and richen the fuel a bit. The sluggish idle and engine stops when just starting points to a lean mixture.

Vinnie

[hawkman]

I would richen the low end:

run the engine at idle

now pinch the fuel line

if the engine pick up speed straightaway you are too lean

get a small screwdriver

place inside the throttle barrel

go ANTICLOCKWISE a little bit....

repeat the fuel line pinch test (pinch the fuel line about 2 to 3 cms from the carb

if the engine idles for 2 to 3 seconds and then picks up and dies then that is good

this is what you want.

Hover the heli

be careful now

punch the throttle/collective UP

the heli should climb without too much effort.

Fly around a bit

Land and let the engine idle....place a finger on the backplate of the engine....it should be warm....not hot....if its hot then the main needle is too lean.....again adjust ANTICLOCKWISE about a couple of clicks...go fly and re test the backplate....if its warm and not hot then its ok.

Any engine wear will ruin the engine, OS make nice engine....so be careful with it.

Also....you might need to check you pitch range and throttle range....an overloaded engine will get hot....if the tail is belt driven...then be careful of the tension of this belt....not too tight!! this can drain the power.

basically you want some smoke....and some oil coming out....if the skid under the exhaust has some oil then thats good.

Any adjustments need to be small....Helicopter engine carbs are quite sensitive.

Rob

[Helgesen]

Thanks guys !
I'll try to pinch the fuel line when I get home from work.
If it stops to fast I will try to adjust the mixture bu turning the adjustement in the middle of the trottle barrel.

On the other side of the carborator there is a big adjustment screw, should I turn this one instead of the center screw?

[hawkman]

No....the main screw....the large one is the 'high end' adjustment....the 'low end' is the small screw inside the carb throttle.

The Low end (inside the throttle barrel) affects the fuel mixture from idle up to and slightly beyond the hover point....the main needle or high end does affect the throttle range overall actually....but it better to concentrate on this for maximum power.

If you fly around and find the performance is not so good as the fuel level goes down you only need to adjust the main needle....one or two clicks either rich or lean is enough usually.

Rob

[Helgesen]

Ok, I have tried the small screw inside the trottle barrel, and it went quite well.
The enginge is now much stronger, and cooler, as well as there is some oil comming out of the muffler.

Thanks guys, this is great!! :-)

[vlam67]

Hi Helgesen,

Good to hear some good news for you in particular, and generally on the forums!

Vinnie

[hawkman]

Hi Helgesen, good to hear that.....the adjustments only need to be small...it better to run slightly rich....having some oil out of the exhaust is a good indication that everything is good.

Dont forget that if you store the helicopter away...make sure to remove the glo plug and put a few drops of light oil into the cylinder....not too much.....put some oil through into the carb as well....use the starter for a couple of seconds....this will spread the oil over the bearings and cylinder.

Otherwise the engine might attract moisture....which will rust the bearings...

Also....if the exhaust/cylinder head is leaking.....remove the exhaust...clean the surfaces and use 5 minute epoxy...10 minute epoxy is ok too....reassemble the exhaust and you should get an oil leak free joint...which helps keep the heli clean.

Rob