RunRyder RC
WATCH
 1 page 720 views POST REPLY
HomeAircraftHelicopterMain Discussion › What is tell tale sign of rich mixture ?
11-07-2013 11:32 PM  4 years agoPost 1
Vaderluck

rrApprentice

Melbourne - Australia

My Posts: All  Forum  Topic

I now learn that rich mixture will keep engine last longer.
For the benefit of noobs, tell us what is the tell tale sign of rich mixture for nitro engine ? How do you tell it is about right ?

PM  EMAIL  GALLERY  Attn:RR  Quote
11-07-2013 11:53 PM  4 years agoPost 2
ticedoff8

rrKey Veteran

Morgan Hill, CA. USA

My Posts: All  Forum  Topic

A rich mixture is not a guarantee of longer life - but it is better to run rich than lean.

Use the finger test - after you land, press your finger against the backplate of the motor. It should be "less than hot". It is burns your finger, it is too lean.

Get a thermometer. Press it against the head around the glow plug after a flight to check the head temp. It the head is around 190 degrees F, then you are in the right range. Hotter than 212 is getting on the edge.

The smoke trail can be a hint, but not definitive.
As a NOOB, you might think it is plenty of smoke, and then you burn up the engine because it is too lean.
Someone with more experience might look at the smoke and say you are way too lean.

Follow the engine manufacture's suggested starting points. Each engine has a needle setting that the manufacturer has tested. These setting should give you a rich, but runnable, starting point. Just, do not get too far off from their recommendations.

PM  EMAIL  GALLERY  Attn:RR  Quote
11-08-2013 12:05 AM  4 years agoPost 3
cudaboy_71

rrElite Veteran

sacramento, ca, u.s.

My Posts: All  Forum  Topic

going by head or even backplate temp is fine. but, temps vary by engine size and manufacturer. 212F-230F on the head may be fine on a .50, but will cook a .91. And, backplate temps are measured in skin temperature--as in how long can you hold it there before flinching.

Just make sure you're using the right numbers, and the right method.

and, to reiterate above: smoke trail is misleading. CY wildcat smokes ALWAYS. rich. lean. doesn't matter. go by that and you'll blow a hole in your piston.

I usually adjust idle with the pinch test. high end is tuned with some full collective punch outs. during climb power should be consistent with no 'gurgling' in the engine. if power starts to die off during the climb you're approaching lean. if it outright wails like a scalded cat you're way to lean already.

unfortunately this is not something easily (cheaply) learned on your own. best to go out with someone seasoned and have them identify the sounds you're listening for as you adjust it. it's a bit of an art.

best advice for a beginner really is to follow the instructions in the manual (which are conservatively rich usually) and work in small increments...a click or two max and go from there.

if it ain't broke, break it.

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
11-08-2013 12:07 AM  4 years agoPost 4
Altrex

rrApprentice

WI

My Posts: All  Forum  Topic

If ur heli is a dripping wet mess at the end of the flight LOL

PM  EMAIL  Attn:RR  Quote
11-08-2013 01:29 AM  4 years agoPost 5
Einzelganger

rrKey Veteran

Campbell, Texas

My Posts: All  Forum  Topic

Best sign I can think of too rich in flight is when you hear it break into two-stroke and then fall back to 4-stroke. That's just a little bit too rich. If you're looking for a good rich setting, hear it in two-stroke almost always, but hear the occasional 4-stroke burble.
Once again, sound. Then, check temp to verify when you land.
Also smell. Rich smells sweet and oily. Lean smells burnt.

Wayne

I love the smell of nitro in the morning.
RIP Roman

PM  EMAIL  GALLERY  Attn:RR  Quote
11-08-2013 03:42 PM  4 years agoPost 6
Wedge77

rrVeteran

St. Charles Missouri USA

My Posts: All  Forum  Topic

Cuda, funny you mention the wildcat, I smoked 2 engines on that, and always had a ton of smoke coming out. I switched to Byrons or cool power because that's what the lhs has on hand, and haventn had any more problems, just kinda clicked when you mentioned that.

JR NEX E8, 12 cell
Goblin 630, 12 cell
Vibe 50N Fbl
Century E640 Fbl, 12 Cell

PM  EMAIL  GALLERY  Attn:RR  Quote
11-08-2013 05:01 PM  4 years agoPost 7
devin120

rrVeteran

Canada

My Posts: All  Forum  Topic

If ur heli is a dripping wet mess at the end of the flight LOL
lol +1

Miniature Aircraft - OS power - Futaba electronics

PM  EMAIL  GALLERY  Attn:RR  Quote
11-08-2013 07:36 PM  4 years agoPost 8
RogerRabbit62

rrVeteran

Thuerigen germany

My Posts: All  Forum  Topic

Temperature might be misleading.
i run the OS91's at a telemetry temp of approx 312F @ 1850x710 Blades and the engine is in perfect shape now after 100Gal approx.
meassured at the second rip of the cylinder area near the outlet.

the engine is exact a little leaner than the "four stroking point"

Measuring a Webra at that point gives similar temps.

temps go down very quick after landing, even when you just reduce load a little, so measuring without telemetrie might be misleading too.

you can run up the temp in a nitro very high by bogging the motor and not let it "run free", so sometimes a little higher RPM and a little less pitch can be helpful.

A good idea for checking the engine is to run full long punchouts and start with rich to lean adjustments until RPM does not increase any more and then adjust a little bit back.
If you then detach the blades and give full throttle the engine should "four stroke" a little.
That is about the optimum point.

from there you can adjust midrange.

PM  EMAIL  Attn:RR  Quote
11-08-2013 09:08 PM  4 years agoPost 9
Vaderluck

rrApprentice

Melbourne - Australia

My Posts: All  Forum  Topic

There is so much to learn (muck around) with nitro engine.
Unlike electric, there is nothing you can tune it. I guess this is part of the fun.

PM  EMAIL  GALLERY  Attn:RR  Quote
11-09-2013 02:16 AM  4 years agoPost 10
wifeorheli

rrElite Veteran

reno, nevada usa

My Posts: All  Forum  Topic

Best write up I have ever seen. By the master of tune tim jones.
https://rc.runryder.com/t630328p1/

Novarossi Motors U.S.A
www.PLanethobby.com
Team GrandRc.com
Team Byron Fuels
ZRC U.S.A. "PushGlo, SwitchGlo"

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
WATCH
 1 page 720 views POST REPLY
HomeAircraftHelicopterMain Discussion › What is tell tale sign of rich mixture ?
 Print TOPIC  Make Suggestion 

 7  Topic Subscribe

Tuesday, August 21 - 2:01 am - Copyright © 2000-2018 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online