Nitro Engine Tuning 101

[Finless]

We shall see

People been asking for a single needle tuning vid like for an OS 50. If I get a chance I will see if I can get something shot.

Bob

[dchekas]

This would be great, perhaps even generalize it more to include 55 class engine tuning.

All the tuning videos out there seem to be for .90 size engines, and they don't sound the same as a .50 or .55.

Thanks Bob!

[evoIX]

i vot efor single needle engine tuning too for people like me who lives in the dessert hahaha

[Sonic_BOOMER_SOONER]

I couldn't find PC Farenheit here in Australia, but at the auto parts store they sell Quik Steel, which seems to be the same stuff. A grey putty that activates as an epoxy that bonds metals when kneaded and works to 500F (260C), which are the same specs I found for PCF online.

[Finless]

Originally Posted by Sonic_BOOMER_SOONER

I couldn't find PC Farenheit here in Australia, but at the auto parts store they sell Quik Steel, which seems to be the same stuff. A grey putty that activates as an epoxy that bonds metals when kneaded and works to 500F (260C), which are the same specs I found for PCF online.

Thats sounds perfect to me!

Bob

[RoyArms]

What would it mean if when you go from a full power climbout to zero pitch if the smoke thins out for a second then comes right back? I am pretty sure the mid range is quite rich as I get thick smoke in a hover, and is still set at break in 1.75 turns out, but I definitely don't get a puff of smoke. Climbouts sound good and consistant for a couple hundred feet so I am thinking the high needle is right. But when I drop collective to neutral the smoke thins out and instantly comes back.

This happens with both gov on and off. T700, Vbar using built in gov, ys 91 3ds with outrage ys pipe.

I tried richening up the mid needle even more but spoolup started to really load up and took much longer.

[Finless]

You should expect the smoke to drop in a condition like this. Your curve or gov is going to be closing the throttle rapidly when you unload. The motor is also not under load so yes a short cut in smoke when unloading is to be expected. As long as it comes right back when you load up again you should be fine.

Bob

[Lost Oracle]

I'm having trouble getting my mid needle tuned. I believe I have the high pretty good. The smoke is nice and opaque and the engine sounds "happy" but whenever I return to a hover it spits out dense white smoke, I can even see droplets of fuel/oil spitting out of the pipe. I've tried to find lean on the mid needle but it seems like I should have either hit it by now (almost ten clicks CW) or I'm doing something wrong.

I'm running an O.S .91 HZ-R in a 700. Anyone have experience tuning one of these or have the same problem with the extremely rich mid?

[Matt Nasca]

Originally Posted by Lost Oracle

I'm having trouble getting my mid needle tuned. I believe I have the high pretty good. The smoke is nice and opaque and the engine sounds "happy" but whenever I return to a hover it spits out dense white smoke, I can even see droplets of fuel/oil spitting out of the pipe. I've tried to find lean on the mid needle but it seems like I should have either hit it by now (almost ten clicks CW) or I'm doing something wrong.

I'm running an O.S .91 HZ-R in a 700. Anyone have experience tuning one of these or have the same problem with the extremely rich mid?

I've found that in our climate (Minnesota) the HZ-R is happy with 1/2 turn +1 or 2 clicks on the mid.

[RAYflex]

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[kz4q66]

I am new to nitro engine. How do you actually SEAL the pipe? Around from the outsite or put thin layer of putty at the contact surface. Thanks.

[cmouton]

Make sure both contact surfaces are clean. Use alcohol. Apply a very thin layer of epoxy on both contact surfaces and clamp it together. Make sure that the muffler bolts are torqed very good. After your first flight, while the engine is still warm, retorq the muffler bolts again. You must check the bolts from time to time, because if they become loose, you will get a leak between the muffler and the engine. Your engine will run leaner and mess up the fuel- air mixture. Or worse, the muffler can fall off, then you lose muffler pressure to the fuel tank with the result that the carburator are not getting any fuel- you will then have a flameout and will need to auto the heli down.

Theoretiically you do not need a sealer or a gasket, because both contact surfaces will "move together"(expand) when it gets hotter or cooler. The only reason I use epoxy is for if there are maybe a very small uneven place (you might not see with your eye) on one of the surfaces that could cause a leak. Good luck!

[kz4q66]

Thank you for your response. I understand what I need to do now.

[Oilsands]

I have a Thunder Tiger Pro 50H motor, wondering what a good starting point is for both needle settings. Never mind, think I found it after reading the manual a few times. Looks like 3 turns out on both needles (low is carb closed and turn in till it stops, then 3 turns out. H is turn in till it stops and 3 turns out.
I have a Thunder Tiger Raptor 50 and I did not find this tilll after the day of flying, but did started what I thought would be close to stock settings. Had the L at 1.5 turns and H at 2 turns. Started up and went into a hover and held it there for a bit, noticed the smoke started to thin out. Set it down and shut it off and check the temp by placing a finger on the back of the motor, no suprise that it was fairly warm. Richened the L and H about 1/2 a turn each, then back to a hover again. Same thing, so richened both again. Started to get better, so richened a bit more. After about 5 hovers, smoke seemed good and it did not loose hover, back plate luke warm (able to hold the finger on it for over 10 seconds). Now tried some full throttle climbs to a comfortable hieght, which is about 70 ft. Since it was cloudy it was hard to tell how much smoke I had, but sound wise seemed like it needed a more rpm. Richened the H needle only 1/4 turn and tried again, a little better. Richened again and seems like it climbs better and sound seems smoother (does not seem like it is bogging down at all).
Looking forward to trying this again when there is blue sky and maybe on a buddy box so that I can climb higher.
Great videos by the way, they really help.

[Oilsands]

Well went back through this thread and now I think I am close with the tuning I did, but think I will turn the needles to the stock setting (3 turns out on each, TT Pro 50H) and go though the tuning again. I need more practice anyways, LOL.

[Oilsands]

Just watched the videos again and noticed that there was no mention of the L or idle needle (mixture screw). Any chance of doing another quick tuning video to mention that tuning or tuning of a 50 motor, where it has a H needle and L needle? Could eventually figure it out but will make it so much easier to see and hear what one is looking for.

[ChadL]

Regarding the video of the 120 SR....I think you summed it up well Bob at about the 5:32 mark .........."Holy Crap".

[razer t-rex]

if you had a header tank would you have to worry about the engine sucking air and goin lean?

[Finless]

A header tank does help for that. However not 100%. As you suck air from the main tank the header tank start to get air in to too. But it still helps a lot!

Bob

[daletheman_3]

Thank you Finless for this video! I have been messing with nitro for quite some time, but until now, have been tuning incorrectly. I was close but my methods were costing me power and run time. I always tuned to temp and, with cars, feel. Just did a retune on my YS56r in my synergy and the power now is better than I have ever had, and I am getting additional flight time. All this and, just for my curiosity, still temping inside my comfort level (old habits hard to break!).


Thanks again!!!!