Tuning Engine ... HELP

[kennethw]

I can't seem to tune my .50 engine properly, hope someone can give me some pointers.

The engine has 2 adjustments, low and high throttle, mid throttle is a combination of both.

The 2 symptons ...

Irritating, but not 'dangerous', the engine cuts when I throttle down after landing (if/when it flies). It does not cut immediately, but it feels / sounds like it is burning all the excess fuel before it slows down and dies. If I increase the idle speed, it will continue to run, but it would just engage the clutch.

Second one has caused me to break the landing gear today. On throttle up, it takes awhile to spool up then it suddenly speeds up. However, every so often, as I spool up and the heli lifts off by about 2 meters, the engine just cuts.

Can't figure it out ... Help please.

[edmond22]

I can't seem to tune my .50 engine properly, hope someone can give me some pointers.

The engine has 2 adjustments, low and high throttle, mid throttle is a combination of both.

The 2 symptons ...

Irritating, but not 'dangerous', the engine cuts when I throttle down after landing (if/when it flies). It does not cut immediately, but it feels / sounds like it is burning all the excess fuel before it slows down and dies. If I increase the idle speed, it will continue to run, but it would just engage the clutch.

Second one has caused me to break the landing gear today. On throttle up, it takes awhile to spool up then it suddenly speeds up. However, every so often, as I spool up and the heli lifts off by about 2 meters, the engine just cuts.

Can't figure it out ... Help please.

Tell us at least the model make of the engine, needle turns and muffler used first, then can help. What fuel, percent, how much smoke observed? Engine sound at idle, engine sound at lift off, bubbly low bass or metallic rattling?

From what you are saying, it sounded like it is too rich at idle making it unable to sustain properly before quitting due to flooding. And it is too lean at top end for flying because you start out rich at the low end, the engine is sluggish, then as you go along increasing it, it clears up but now transit into the lean top end setting, engine suddenly goes alive, and quit.

Second para is just a guess, best to let us know more first. Easier to diagnose.

[kennethw]

Thanks for the response.

The engine is a Thunder Tiger RedLine 53L.

The setting at the present time is 2.85 turns open on main needle value (instructions say 3) and the trottle needle is about 1/4 turn rich from factory.

I'm using 15%.

Little smoke at idle and quite a lot of smoke at higher RPM's.

Oh, muffler is an RJX.

Engine sound at idle seems quite smooth at startup, but when bringing throttle down and engine slows down just before dying is a little bubbly with some metallic 'tinging'.

Hope this helps.

[edmond22]

Thanks for the response.

The engine is a Thunder Tiger RedLine 53L.

The setting at the present time is 2.85 turns open on main needle value (instructions say 3) and the trottle needle is about 1/4 turn rich from factory.

I'm using 15%.

Little smoke at idle and quite a lot of smoke at higher RPM's.

Oh, muffler is an RJX.

Engine sound at idle seems quite smooth at startup, but when bringing throttle down and engine slows down just before dying is a little bubbly with some metallic 'tinging'.

Hope this helps.

15%, best to ask Ken, he was running 15% alot then.

For myself, I ranged from 3 turns to 2.75 turns on 30% on the tt53 with hatori. No experience with RJX muffler but my guess is you are probably too rich esp on the idle needle. Normally, most tt53 engine I come across lean the idle needle slightly from factory setting to arrive at a nice idle. What was the temperature like when it quits?

[RAPTOR2001SG]

Rotorhobby boss Walter told me 2.5 turns for main neddle engine break in , after half gal run soft then tuen in two kick , mixture screw no need to adjust then should be ok . will be break in later.

[kennethw]

An update, I think I got the high end working nicely, but the low end is still a 'problem'.

When I start up, it idles OK, and when I increase throttle, it is hesitating a little but will get up to speed. However, when I lift off, the engine then seems to really spool up as if it cleared a flood and can run. Then when I land and drop the throttle to idle, it chokes and dies.

I think my low end is too rich hence the 'flooding' and bad transition.

I'm going to lean the low end out tomorrow morning, unless there is violent objection.

Thanks.

[edmond22]

An update, I think I got the high end working nicely, but the low end is still a 'problem'.

When I start up, it idles OK, and when I increase throttle, it is hesitating a little but will get up to speed. However, when I lift off, the engine then seems to really spool up as if it cleared a flood and can run. Then when I land and drop the throttle to idle, it chokes and dies.

I think my low end is too rich hence the 'flooding' and bad transition.

I'm going to lean the low end out tomorrow morning, unless there is violent objection.

Thanks.

Sounds like you are getting there

What is the high setting like now? No violent objection, just keep a watch on temp at all times. Basically, when you are adjusting the high end, you will need to probably tune the low end a bit to suit (which is where you are now).