Upside down engine?

[300cpilot]

What would happen if my Yamaha 540 2-stroke engine was mounted with the plugs down instead of up, ontop? This would put the carb towards the seat and the exhaust out the back? I would just spin the carb around so that it is right side up. I have a feeling it would be a plug fouling pig, but am curious what others would think?

There is no oil in the crankcase, so I believe it would work, but wonder why no one else ever did it? Heck my weed eater runs fine upside down.

[metalstudman1]

IMO-Since I know little to nothing about 2-strokes-but do understand engines and lubrication, I would think it would starve the crank of oil at some point due to gravity. I agree that you can run 2-strokes at any angle but that's not for the majority of the time.

[300cpilot]

Thanks that is a good point. I have no idea how the gas/oil cycles through the engine before it is burned.

I have been looking around and apparently they mount these things upside down on mini air boats? I have not seen anyone say they have blown up yet. But still I am going to make sure before I do it.

[metalstudman1]

Again I'm no expert!!!Just learning about them through my build.I know there is 2 different styles & places the reed cage enters the motor.Is the reed cage on the head or the block? I'd think if the reed cage is on the head it would probably run upside down just fine-but if on the block that's where I'd be concerned about proper lubrication on the crank.Also the oil injection systems does something for one type too. Just throwing opinions out there with no experience to verify.

[300cpilot]

Expert, yep your the closet thing to one in this discussion! I believe a enough questions are raised to abandon this thought process. We also discovered that the air cooling fan would be about 12" off the ground and would suck up much more dirt.

Thanks for your help. Right side up it is.