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View Full Version : When is too little, too little (oil)?


FCM
04-11-2004, 09:08 AM
Thought I would post this in case there is anybody else out there who cannot obtain the popular oils for gas helicopters - Amsoil, Klotz etc.

I have been experimenting with a couple of very different oils in my G230RC Benzine camera ship over the last few weeks.

The first oil I tried was Silkolene Comp 2 fully synthetic (some may remember my posting on another forum) at 42:1 ratio using unleaded 92 RON petrol.
This oil seemed to work well at this ratio and the spark plug colour was grey with no signes of overheating or fouling.

I then tried Motul 800 which is an expensive road racing fully synthetic ester based oil from France. This oil is very thick in consistancy and is difficult to syringe out of the container even at our high ambient temperatures here. I would estimate that it is at least twice as thick as the Silkolene Comp 2.

The recommended ratio is 50:1 which I tried and found that the spark plug fouled and was always black and wet even with the engine fully leaned. After contacting Motul and receiving the info. that it is okay to run "trail bikes at 100:1" I have been gradually reducing the oil content to see what happens.

I am now on 70:1 ratio but the plug is still wet although I do have a very dark brown colour appearing which wasn't there before. Engine seems happy enough although I have only run 2 tanks through at this ratio.

I am wondering if it will be safe to reduce the oil content further to say 80:1 given that the plug at 70:1 is still wet? I am now debating whether to go back to the Silkolene at 42:1 or continue the testing with the Motul 800 in order to gain the benefits from running a lean oil ratio which I am given to understand should allow the engine to run cooler.

Paul.

Al Magaloff
04-11-2004, 01:57 PM
Paul, experimenting beyond where you've gone could cost you the motor. My question to you on the plus is: When you remove the plug and it's wet, does it stay wet, or will it dry? If it's wet and stays wet, it is most probably oil fouled. An oil fouled plug may not clean itself by running it again, so a new plug may be needed, before any further"testing" can go on. If the plug is wet, but dries, it's fuel fouled.

FCM
04-11-2004, 10:55 PM
The plug stays wet so I guess it is oil fouled but it seems to clean up okay and the engine is running smoothly. This may be due to the fact that I am not running for very long therefore minimising the contamination.

I agree that I may be putting my engine at risk so I am leaning towards reverting back to the Silkolene Comp 2 at 42:1 ratio.

Shame I can't obtain Amsoil here!

FCM
04-12-2004, 02:25 AM
That's it, I've just mixed up some petrol at 42:1 using the Silkolene Comp 2 as I have bottled out of running the Motul 800 any leaner than 70:1.

May continue with the Motul oil on another occasion but need the heli to be operational now for filming.

Would still be interested in anyone's opinion re: Motul 800 oil ratios.

Paul.