Needle adjustment / turns

[cloudstrife04022006]

Good day. just wondering how many turns in your needle do you have on you os .50 engine to get mac performance. Im using a 30% nitro and stock align muffler (came with my t6nsp)

[chadjay]

This will vary based on elevation and ambient conditions. If you are breaking in use 1.5 turns out from fully closed. Burn at least 3-5 tanks with it at 1.5 turns out.

You will most likely end up 1 turn to 3/4 turn out after break in.

[srhadden]

Seems like a lot of people favor the 30% instead of less. I can only get 15% or 30% around where I live.

[TheBum]

Originally Posted by srhadden

Seems like a lot of people favor the 30% instead of less. I can only get 15% or 30% around where I live.

I've been using 20% lately and have definitely noticed a loss of power. Part of the problem is the climate this time of year: hot. Nitro engines don't make as much power in high ambient temperatures. I'm seriously considering going to a seasonal approach: using 30% during the summer for the extra oomph and 20% in the autumn through spring.

[pril250]

You can mix 15% and 30% 50/50 to get 22.5%.

[srhadden]

Using 15% my low screw is 3/4 closed and my needle is a few clicks lean of 1.5 turns. With 15 my low end needs to be very lean or the engine dies at rev up.

[BarracudaHockey]

Saying that you're running 30 percent isn't enough. It depends on what fuel, particularly the oil percentage, as well as the weather, and a few other factors.

Start rich, 2 turns or so for 30 percent and tune from there for a clean running engine thats not too hot.

[tukkus]

I recently broke in a new Hyper engine at 1 1/2 turns out using 30% and the fuel(Wildcat) was spitting out of the muffler. I have leaned it out some and now it runs better and I can get a little more flying time out of it.

[srhadden]

Can the performance be strictly determined by the running temperature? For example, if the temp on my engine is 220F when I land, should I therefore stop making adustments?

Or can you get a better running engine by adjusting the low-end and the high-end? For example, richen the low end and lean the high end to comensate? From what I understand it would not matter, once the engine revs past a certain point I thought it is majorly the needle value that is controlling the fuel flow.

[BarracudaHockey]

The low needle should be set for clean transitions. The best way to get it close is to put the heli in a hover to clear out the engine, land and pinch the fuel line and start counting.

If the motor speeds up and dies or just cuts out, the low end is too lean. If it runs for more than 4 or 5 seconds w/o speending up its too rich.

A good way to tell if your motor is too hot is to take it up and flip throttle hold, if it settles right into a nice idle its in good shape. If it does that rat tat tat all the way down its too lean. 220 after you land and check the temp is probably a little on the warm side, I'd shoot for 220 in flight with 205 or so by the time you can land, spool down and shoot it with an IR

[cb3d]

Originally Posted by BarracudaHockey

The low needle should be set for clean transitions. The best way to get it close is to put the heli in a hover to clear out the engine, land and pinch the fuel line and start counting.

If the motor speeds up and dies or just cuts out, the low end is too lean. If it runs for more than 4 or 5 seconds w/o speending up its too rich.

A good way to tell if your motor is too hot is to take it up and flip throttle hold, if it settles right into a nice idle its in good shape. If it does that rat tat tat all the way down its too lean. 220 after you land and check the temp is probably a little on the warm side, I'd shoot for 220 in flight with 205 or so by the time you can land, spool down and shoot it with an IR

Nice tips. I hadnt heard the throttle hold one before.

[Sonic_BOOMER_SOONER]

Originally Posted by tukkus

I recently broke in a new Hyper engine at 1 1/2 turns out using 30% and the fuel(Wildcat) was spitting out of the muffler. I have leaned it out some and now it runs better and I can get a little more flying time out of it.

Tukkus, my brother-in-law has been flying competitive control-line planks for over 30 years and has owned over 150 OS 50s. (Some of those he purchased, rebuilt, tuned & sold.) He says if you want the engine to last the maximum time between rebuilds you want just a touch of fuel spitting out the muffler periodically. You can get better performance from there, but you will be rebuilding more frequently. Just an fyi...

[heli07]

I have been checking the backplate on my engine for temperature with my finger ,,just barley warm. where are u guys checking the temp with a ir gun & what should the temp be ?

[srhadden]

I'm running about 190 degrees measured with a temp gauge between the blue head and the back plate. I measure it as soon as the blades spool down. I can hold my finger on the backplate for about 5-10 seconds. Seems to be right from everything I've heard. I also have tried to pinch the fuel line as soon as it spools down to see the motor goes lean after about 2 seconds of pinching the line, and you want it to run about 5 seconds before dieing out. But I am mainly going by temp.