Great post, thanks again Terrycustom!!!!

great method for tuning engines.....since the day i've used this method, my engines have run a lot smoother!

My engine tuning skills or not the best so I'll be reading this for sure

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?

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.

Originally Posted by aronph

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.

uhm....everything I have read about the autotune/mtronic saws everybody says it rocks. But ok.

Originally Posted by aronph

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.

As a dealer (CAT) mechanic I totally agree. People have no idea what it takes to service a electronically managed engine.

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

Thanks Terry, I printed off several copies to hand out to the guy's at the field who are struggling a bit with tuning

Originally Posted by Tora117

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

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.

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.