logo

Engine Tuning Basics from Terryscustom

First time gas aircraft owner? Learn to tune a gas engine from Terryscustom!

Splash

Keep 'Em Running With Advice From Terryscustom!

Most of us (including myself) have experienced the reality check of your first gas engine that won't start, won't stay running, runs poorly, or quits in flight! You've invested in a high quality aircraft and all of the accessories, and now you're struggling with the basics of tuning those needles. Luckily, our good friend terryscustom put together one heck of a beginner's guide to chasing the needles. Even though this thread is over a year old, I think there's no better time than now to share with everyone some good advice, especially with the flying season fast approaching. Click below for the full thread on FlyingGiants.

Basic Engine Tuning - Keeping It Simple

CLICK HERE for Terry's thread: Basic Engine Tuning - Keeping it Simple

PDF summary of Basic Engine Tuning, created by Judge

Last edited by Matt Gunn; 03-13-2017 at 02:41 PM..
Thread Tools
Old 03-14-2017, 09:23 PM
obriendigital is offline
Find More Posts by obriendigital
Registered User
obriendigital's Avatar
United States, NE, Ashland
Joined Dec 2008
481 Posts
Great post, thanks again Terrycustom!!!!
obriendigital is offline Find More Posts by obriendigital
Reply With Quote
Old 03-15-2017, 12:08 AM
bluefear is online now
Find More Posts by bluefear
Registered User
bluefear's Avatar
Joined Feb 2013
240 Posts
great method for tuning engines.....since the day i've used this method, my engines have run a lot smoother!
bluefear is online now Find More Posts by bluefear
Reply With Quote
Old 03-15-2017, 01:04 PM
Tora117 is offline
Find More Posts by Tora117
Rc_3d_pilot
United States, TX, McKinney
Joined Jan 2017
21 Posts
My engine tuning skills or not the best so I'll be reading this for sure
Tora117 is offline Find More Posts by Tora117
Reply With Quote
Old 03-15-2017, 03:07 PM
aronph is offline
Find More Posts by aronph
TEAM HILLBILLY
United States, OH, Groveport
Joined Jul 2011
373 Posts
This may be a dumb question but if chainsaw manufacturers (Stihl & Husqvarna) have "autotune" engines that dont have needles, why cant we put that tech into planes?
aronph is offline Find More Posts by aronph
Reply With Quote
Old 03-15-2017, 04:06 PM
CARS II is offline
Find More Posts by CARS II
Go fly a jet today
CARS II's Avatar
United States, CA, Sacramento
Joined Oct 2014
329 Posts
Awesome tuning instructions Terry, I put them to work just yesterday with my DLE 35, the instructions are simple, clear and easy to follow with excellent results.
CARS II is offline Find More Posts by CARS II
Reply With Quote
Old 03-15-2017, 06:08 PM
Eric_04 is offline
Find More Posts by Eric_04
Registered User
United States, WI, Fond du Lac
Joined Jan 2017
146 Posts
Quote:
Originally Posted by aronph View Post
This may be a dumb question but if chainsaw manufacturers (Stihl & Husqvarna) have "autotune" engines that dont have needles, why cant we put that tech into planes?
They do have needles. Autotune fails frequently and requires a computer and software for diagnostics. Autotune is also only able to adjust for minute differences. Say you have an engine problem such as an intake leak, with a standard carb your engine would run poorly but you would be able to make it back to land safely. That situation is far out of any autotunes ability to adjust for. It will compensate until it gets too far out of range to adjust for and then the engine will just quit with no notice or symptoms. Its also more wiring and a mini ecu to have on board as well as another item to power, unless you run the stator and wiring under the flywheel.

You can have autotune. I will stick to a standard carb. Who would pay possibly twice the price (or more) for say a 50cc engine with autotune than one without? In my opinion, as far as airplane use, autotune is a poor option with its current technology.
Eric_04 is offline Find More Posts by Eric_04
Reply With Quote
Old 03-15-2017, 07:41 PM
aronph is offline
Find More Posts by aronph
TEAM HILLBILLY
United States, OH, Groveport
Joined Jul 2011
373 Posts
uhm....everything I have read about the autotune/mtronic saws everybody says it rocks. But ok.
aronph is offline Find More Posts by aronph
Reply With Quote
Old 03-15-2017, 10:05 PM
Eric_04 is offline
Find More Posts by Eric_04
Registered User
United States, WI, Fond du Lac
Joined Jan 2017
146 Posts
Quote:
Originally Posted by aronph View Post
uhm....everything I have read about the autotune/mtronic saws everybody says it rocks. But ok.
Im a small engine mechanic, and have been for quite some time. You would be shocked at the amount of commercial use stuff that comes back for repair. Im not talking about homeowner stuff that gets used a couple times a year. Stihl mtronic diagnostic software is $2200. That doesnt include the laptop, or the fact you have to be a Stihl dealer to get it, or the subscription that you are forced to buy annually or the software wont function.

Ask any logging or concrete company. NONE of them want autotune saws. Why? Because they cant fix them. They have to be taken to a dealer. If it doesnt run they are up a creek without a paddle. Logging guys are real impressed when they carry their saw, gas can, and wedges 1/2 mile into the woods and then their saw doesnt start.

You can read all you want, I deal with it daily.
Eric_04 is offline Find More Posts by Eric_04
Reply With Quote
Old 03-16-2017, 03:58 AM
lc39tech is offline
Find More Posts by lc39tech
Registered User
United States, FL, Cocoa
Joined Oct 2009
60 Posts
As a dealer (CAT) mechanic I totally agree. People have no idea what it takes to service a electronically managed engine.
lc39tech is offline Find More Posts by lc39tech
Reply With Quote
Old 03-16-2017, 11:47 AM
Tora117 is offline
Find More Posts by Tora117
Rc_3d_pilot
United States, TX, McKinney
Joined Jan 2017
21 Posts
For all the people up there ^^ DA makes engines with EFI such as the DA 120 EFI that are designed for uavs or paramoters but can be put in a plane
Tora117 is offline Find More Posts by Tora117
Reply With Quote
Old 03-16-2017, 01:53 PM
flymedic is offline
Find More Posts by flymedic
Huckin Fire Trucker
flymedic's Avatar
United States, AZ, Littlefield
Joined Jan 2008
1,353 Posts
Thanks Terry, I printed off several copies to hand out to the guy's at the field who are struggling a bit with tuning
flymedic is offline Find More Posts by flymedic
Reply With Quote
Old 03-16-2017, 06:56 PM
Eric_04 is offline
Find More Posts by Eric_04
Registered User
United States, WI, Fond du Lac
Joined Jan 2017
146 Posts
Quote:
Originally Posted by Tora117 View Post
For all the people up there ^^ DA makes engines with EFI such as the DA 120 EFI that are designed for uavs or paramoters but can be put in a plane
Ill just leave this here...
DA 120 EFI MIL SPEC UAV Engine

$17,187.00

Only $16,988.00 more than a standard DA 120. Im surprised more people dont have these installed on their planes
Eric_04 is offline Find More Posts by Eric_04
Reply With Quote
Old 03-16-2017, 07:06 PM
Colton is offline
Find More Posts by Colton
Now taking manuver requests!
Colton's Avatar
United States, AZ, Tucson
Joined Mar 2010
2,251 Posts
Non MIL SPEC engine is only $3932

So only $2733 more than a standard 120. This is what it costs to make this happen. It's not for most right now and we actually are just completing longevity testing. My plane just sat for 7 months and with literally only putting fresh gas in the tank (not changing fuel lines or even priming the system) it fired right up on the second flip and ran exactly as it should.
Colton is offline Find More Posts by Colton
Reply With Quote
Old 03-16-2017, 07:18 PM
Eric_04 is offline
Find More Posts by Eric_04
Registered User
United States, WI, Fond du Lac
Joined Jan 2017
146 Posts
Please understand Im not knocking the benefits of EFI. But for my personal use, a well tuned carb does everything I need. I understand the added complexity and cost of EFI well. Im sure it would be great for some, but I personally dont want or need what fuel injection has to offer. At least not as far as RC planes go anyways. For the difference in cost I could build another plane.
Eric_04 is offline Find More Posts by Eric_04
Reply With Quote



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools