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2 Day Rotax Maintenance class at Lockwood


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Here are some notes I made. You probably know this stuff but I found the class very informative.

Turn prop slowly thru compression stroke when burping.

Set idle for 1600 rpm

 Newer gearboxes have an oil jet.  New gearboxes are $4300

When removing spark plugs, be aware that some of the threads are exposed in the combustion chamber. If the plugs don’t unscrew easily they may have buildup on the threads. You must carefully work the plug back and forth to work it out. Forcing them can cause damage to the head. Always use “silicone heat paste” on the new plug threads. Not too much. Lockwood part no 897.186a. 
be sure to pull plug wire straight off. Pulling at an angle can damage the plug wire. 

Sea Foam in fuel and oil will remove lead deposits. Run plane hard then change oil. 

Magnetic plug debris most likely from gear box. A little fuzzy paste is normal. 

Run ups with the IS (fuel injected) engine are not necessary. The lane check takes place at engine start up, so if lights go out, there is no reason to do it again.

Crack throttle 40% at start up.  (IS) If engine is cold warm up at 2500 rpm or more. Don’t let the engine idle. It’s hard on the gear box. 
Lane A produces 16 amps. Lane B produces 30, so you want to blip the engine to 2500-3000 rpm to get line B to engage. 

IS engines have to go thru a diagnostic in annual using the Rotax BUDS software ( free) but you have to use the Rotax “dongle” to plug into the plane. They cost $1700. 

Hands on we did a mechanical then pneumatic carb sync. , oil change, oil can cleaning, plug changes, and compression test.  











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I always like to hear the objective science behind statements such as Sea Foam picks up lead deposits.  Often this kind of statement is made based on subjective observation, not science.  Can you ask your instructor to  provide the science behind it and then post for the benefit of the rest of us? Thanks.

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I'm not a chemist, but I know what some of the materials are and I'll let the chemical buffs out there determine.

Lead deposits as lead oxide in the engine, or if run with TCP / Decalin, it is converted to lead phosphate.

Seafoam's composition is mostly pale oil, naptha and isopropyl alcohol, with a small percentage of unidentified ingredients, but it's pretty much all petroleum based stuff if we are to believe seafoam's marketing and MSDS.

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I don't use fuel treatments as I avoid 100LL, but the same topic came up in the 2 day Rainbow class, instructor was Jim Scott and has some credentials.  He shared story of a 912 that ran a whole pile of hours on 100LL and had issues.  Said they took it to the end of the ramp (specifically said don't do this in front of hanger), and with it running fed in seafoam through carbs to the point of just keeping it running, told how much crap came out of the exhaust, and issues resolved.  

Not arguing for or against this, but sharing data point that Rainbow Aviation has presented the same information for removing lead within Rotax 912 engine.

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I only run 100LL in my Sling in winter and 91 non ethanol, unleaded the rest of the year. Avgas keeps it’s octane rating longer than MOGAS and it can be a month or more sitting due to weather here in the Northeast. I’ve not experienced any issues with excess lead and do oil changes every 25-30 hours. I use Blackstone for my oil analysis. I’m not familiar with sea foam. I use Decalin RunUp. 

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