soarrich

My Feedback: (98)

Hi

I converted a Ryobi for my plane. I first ran it in Jan '02, it ran like a champ. I adjusted the carb just like a glow engine, the high speed I got 7100 rpm with a 16 x 10 Master A S, the low speed was down to 1700 rpm, but I set it on 2100 for safety.

I flew it that way a few times, I was very impressed. The one day it wouldn't slow below 3500 rpm for landing. Today I took it out, I'm still getting 7100 rpm, but about 2400 rpm is the lowest I could get it to idle, and I have to be very careful when advancing the throtle or it dies. The engine also seems to snize during taxing(3500 rpm) and then dies.

What happen to my engine to change it?

w8ye

My Feedback: (16)

It sounds to me like your engine is sucking air from some place beside the carb.

The back plate may have loosened from the crankcase

The carb is held on by two sheet metal screws, it may have loosened.

The butterfly my have come loose from the shaft in the carb.


Your reed valve may be partially sprung but I doubt it.


you may also check your magneto and spark plug gaps.


But the most likely cause is the AIR LEAK!

I have one that was originally a Lawn Boy. But its a Ryobi if there ever was one. It also does 7100 with a 16-10. It still runs OK. They do a lot better with a carb from the Zenoah 23 on them but are perfectly usable as stock.


Enjoy

Jim

kevin mcgrath

My Feedback: (1)

Sounds like an air leak to me too,and the most likely spot is the joint between the plastic back plate and the carb or cylinder.Be careful tightening those long coarse thread screws into the plastic as they will strip easily.If an air leak is not apparent then go back to basics,and check through all fasteners,and the entire fuel system.I agree any problem with the reed valve is unlikely and I would mess with it only if all else fails......good luck and let us know how you make out.Any gas experts in your club?sometimes a fresh pair of eyes will spot the obvious that we miss in our upset over the engine going sour...

soarrich

My Feedback: (98)

Thanks guys, I look for a air leak and report back what I find.

The back plate had loosen once before after running it in the back yard, although I didn't notice any problems other than the engine about to fall out of the plane! Should I use locktight on those corse screws in the backplate? If so Blue or Red?

w8ye

My Feedback: (16)

Go ahead and just use the blue. To ever get the screws out, you will need to warm the case up in the area where the screws are. The reason to not use the red is because of the plastic backplate. You don't want to melt it when you are trying to get the screw out. The red is some tuff stuff. I had Some McColluch engines that I had to heat up with a torch to get the screws out. It had a plastic back plate and I didn't harm the back plate.

Good luck,

Jim

soarrich

My Feedback: (98)

I took the engine out of the plane, it seems like the backplate is on tight, and the carb is on tight also. I took the carb off, and the reed valve seems to be closed all the way, so I don't think that's a problem. I did find that the pickup for the flywheel has a bigger gap than I set it at. I put it all back together, we can't fly on tuesday at our field so I take it out tomorrow for tests.