Coming up on Rotax 1st start

[Guest Mike Rosen]

Recently finished my RANS S6-ES. In the hangar in Bennington, VT. Need to pressurize and purge the oil system since I found the hydraulic lifters are mushy. I'll either build the tubes/fittings/gauge or buy the kit from Lockwood. Wish me luck. Anyone know of a trouble-shooting checklist of the engine won't start?

 

Mike Rosen

 

 

[Guest Maj Millard]

Sounds like a 912 ??...I'll assume it is. Priming and purging your oil system is very important, and must be done per the Rotax service bulliten instructions. If you don't have them, you need to get them. In a nutshell it goes as follows...but you still need to refer to the SB.

 

Put between 2.5-3.0 lts of oil into oil tank. No more, they don't like to be overfilled, and like to operate about 3/4 up the flat on the stick.

 

Remove at least one set of spark plugs. (top or bottom, or all if you like.)

 

You must perform the following with the ignition circuts grounded IE: both switches OFF. or serious damage to your ign boxes could result. You must make sure you have the switches wired up right. IE: MAKE SURE off is off, and on is on. Ign systems MUST be grounded in the OFF position.

 

Then have somebody apply a small amount of pressure onto the oil tank vent tube. SB says a max of 15 LB PSI. While this pressure is applied spin the engine over on the starter until oil pressure appears and starts to rise on the oil pressure guage.

 

Additionally if you have plenty of help you may disconnect the RETURN oil line to the oil tank and place it in a container to catch oil. When new oil comes out of this line you will probabily have oil pressure appearing on your guage.

 

CAUTION: do not run your starter longer than recommended in the SB.

 

All persons must remain clear of the rotating propellor at all times.

 

Sometimes you get oil pressure pretty quick, sometimes you don't, it depends on the particular installation.

 

Repeat the above until you get oil pressure on the guage, it will rise steady when it comes. You must get that indication. Keep the pressure on the vent tube.

 

When you've got it , reconnect everthing, refit spark plugs and leads, and start engine. When it starts you must get oil pressure on guage within 30 seconds, if not shut it down.

 

Can only be a couple of reasons for engine not starting: Ign switches no wired correctly. IE: ON is actually OFF, and OFF is actually ON,fix it!.

 

or: no fuel in bowls.......remove each carb bowl, fill with fresh fuel and refit. Don't loose the cork gasket !! If it starts fine, runs for a bit then stops you may have a fuel supply problem to the carbs. Good Luck and watch that prop !!

 

Additionally you must get the Rotax SB that tells you the correct method to 'burp' the engine when checking the oil level. Follow this proceedure and you'll be fine . Don't follow it ...watch out !!.