themanimal

My Feedback: (1)

So the Saito debacle continues. So using all the great advice from the previous post I was able to get the engine running pretty well and idling at around 2100. I was pretty damn happy. I went out to the field and things were going well but as this was my maiden flight on a new kit I taxied on the runway long enough for the engine to richen up and sputter out when I advanced the throttle. This happened twice.

I leaned the idle mixture a tad bit and got the plane in the air. After about 3-4 minutes in the air I could hear the engine loading up and slowing down. I sped it up, slowed it down to no avail and ended up making a down wind dead stick landing into a recently plowed, yet soft field. No damage to the plane and didn’t even break the prop. Then the fun started.

I leaned the high speed setting a bit and started the engine. It would not run past half throttle without quickly dying (the engine did not like the throttle being advanced at all past mid point). I put the needle back where it was. Still no improvement. I gave it several clicks richer and several clicks leaner on many different occasions but the engine would now only stay running at about ¼ throttle. It was almost as if there was an air leak or something. I checked the fuel level, the hose connections etc and came up with nothing…. L. The only thing I could see was a small amount of fuel leakage where the cylinder body bolts to the crankcase.

Any suggestions for me…Please!! Do you think the valves need adjusting? Should I take the engine apart and put instant gasket between the crankcase and the cylinder? Would a blockage in the needle valve make it act like this? Should I smash the engine with a hammer and buy a brand new one?

Other facts..
Used saito .91
15% synthetic/castor fuel (fresh)
new 4-stroke glow plug (s)
Mounted inverted on a super chipmunk

Thanks for any help

canadagoose

My Feedback: (2)

There's no need to put sealant between crankcase and cylinder, only 2 cycle motors need to have the crankcase sealed from any air leaks. the crankcase on a 4 stroke will have a slight positive pressure in it while it's running caused from blow by. I would suggest using a OS F plug and 15% nitro fuel. If the throttle is advanced and the engine quits while opening it, that's usually an indication the low speed needle is too lean. If the valves have too much clearance, the engine will usaully run but not well. I would suggest replacing all fuel lines open the low speed needle about 4 turns and the high speed about 2-2 1/2 turns as a starting point. Also check if you have any, the quick fueler valves as those can leak in air, and check the valve clearnace. Also do not lean a four stroke too much, you should set the high speed needle a little rich. I've never mounted any of my four strokes inverted, a buddy had a Saito 45 mounted that way in one of his planes and i remember he had some problems with it. To me it sounds like it's too lean. Are you sure that it loaded up when you had it in the air and didn't quit from overheating.

P.S. Don't smash it with a hammer, send it to me, i'll even pay for the shipping.

rc-sport

My Feedback: (12)

Your Low end is too lean, open it up an 1/8 turn at a time till you can advance the throttle with out it dying then work on the high end. I have 3 Saito's that are inverted and they all run perfectly.

Josey Wales

My Feedback: (61)

What he said!!!

tailskid

My Feedback: (34)

I had the same problem with a new Saito 100.....we turned CCW the low speed adjustment over 3 turns.....and now it idles like a kitten - and it is still 'new'!

Jerry