Engine Prob - Need Help

I have an interesting problem. I have Lanier Stinger 60 ARF with a Saito

80 in it. The engine will not turn max RPM with a full tank of gas on the ground ( Throttle opens completely- No problem). After 2 to 3 minutes of flying the engines speeds up to max RPM and then flies fine for the rest of the flight. Everything about the plane is stock. I checked everything and found nothing. Thinking it was the engine I swapped it out for an OS 60 FX ( 2 stroke) . Now the same thing is happening to the new engine. I am going to swap out the fuel tank and fuel pick up assembly. But at close inspection it looks fine , no leaks , clogs ,airtight etc. It is a standard 360cc tank .It is not rigidly mounted, but rest in a bed of foam with some freedom of movement.

Every single person at the field has at least two opinions , but none have solved the problem. I am at my wits end , I love this plane , it is the third one I have had , they fly beautifully. I also know now how to strengthen everything. ARFS are not as strong as the kit version.Experience is a great teacher.

Please help.

ACE

Reply to
Allan Schneider
Loading thread data ...

More info, please. What happens when you adjust the high speed needle on the ground? Did you lean it out until it went too lean, then back off alittle? What size prop, what are max, Rpm on the ground?

Reply to
Bill Bunn

I have no idea why yur Saito did not run well. I am flying one with a

14/6 and 10% fuel and it really turns up. Assuming all things to be ok in that area...glow plug, fuel and prop...maybe you have a restricted or crimped fuel line. Let us know what you find.. Odd, I had a Stinger 60ARF with ST75 on it and it flew great, but for some reason I was not really in love with the plane..sold it and now I think I made a mistake..... Frank
Reply to
Frank Schwartz

High Speed needle adjusts correctly on the ground for both engines.Prop for the Saito is 13/9 APC and 13/7 APC for the OS. I did not check the rpm on the ground , But the increase in RPM while flying was clear to everyone on the ground and at the field that day - actually several days . This has been a long standing problem.

Reply to
Allan Schneider

I am coming to that conclusion well and will check the tank and post the results . Someone also suggested that I may be dumping fuel into the muffler as I filled the tank to capacity.And it is thus drawing very rich mixture. I am going to check the pressure line into the tank and post the results.

I am also going to put the Saito on another plane . I have a second Saito 80 and it is a gem .I suspect that this one is as well.

Reply to
Allan Schneider

How is your exhaust trail as it speeds up in the air? Is it about the same before and after the speed up? Perhaps you are running a little rich on the ground then it leans out a little as the tank level gets lower.

Reply to
JJVB

Another thought. Perhaps you have a pinhole leak in your fuel supply line inside the tank. When the tank is full, it isn't a problem. When the level gets below the possible hole in the line, it lets air bubbles in the line and the engine leans out a little.

Reply to
JJVB

Allen: A 13x9 is entirely too much prop for a Saito .80. No wonder it picks up a few Rs in the air. My Saito .80 was just about able to turn a 14x6 in a biplane and is now turning a 12x7 APC in a WW2 fighter model. I run 13x7 Apcs on my 2 .91 4 strokes.

Reply to
Bill Bunn

I ran 13x6 props on my Enya .80. Lots of folks will tell you that it was one of the only Goldberg Cubs that they had seen that would actually climb in knife edge. Not enough ground clearance for a 14x6, although the engine would handle it, and the model wouldn't land with a 13x8 if the engine was still running.

I really miss that model. It was a good one.

Ed Cregger

Reply to
Ed Cregger

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.