I'm breaking in a new Saito 180 on an Edge 540 (H9). Things were going great until I taxied in from a flight today. This was about the 8th flight on the bird, and the 12th engine run. It sounded like a washing machine with a bad belt. It runs oK, though power seems to be off, but this loud metalic squeeking indicates some sort of trouble.

Anyone experience this?

Mystified in Michigan

It sounds like a bearing is getting ready to go. Since it started so suddenly, I'd send it back before running it anymore. I saw one bearing come apart without warning once, and that was a mess. Since it's a Saito, you need to send it back to Horizon Hobbies. http://www.horizonhobby.com

Right you are, Sir!

I did send it in to Horizon on a Tuesday, got a call on Thursday with the gory details. Had the engine back on a Friday. Excellent turn around!

It was a rusted rear bearing, of all things! The engine was under warranty, but I was told this was not covered. The total expense was about $45.

I use after run after every day of running, but the engine has only had about 14 runs on it since new, over 18 months old. I suspect the bearing might have had rust in it when I bought it.

I guess the thing to do is to be very aggressive with the after run oil, maybe take off the backplate and squirt inside after the season is over. Are there any best practices that you know of? Any cheap but good substitutes for after run?

FF

When you are putting after run oil in it, are you putting it in the breather nipple on the bottom of the engine or on the glow plug hole? On a 4 stroke, it needs to go in the breather nipple. Something else that I do after I'm done, is I'll stick a piece of fuel tubing over the nipple with a plug in the other end. If there is a piece of tubing over the nipple anyway to direct oil away from the plane, just stick a plug in it. This will help keep oil from dripping out, and will help keep moisture out. That's what I do, and I haven't had a bearing go bad yet in an engine that I've been the only owner of.

No, I've not been doing it this way. I've been putting it in the carb. I'll try your advice and see what happens!

Thanks, and happy aviating.

Jack

Jack, I was just wondering if you are burning all the fuel out after each day of flying? If not the after run oil could make things worse. You should put the glow plug on and try to start it till it wont fire after each day of flying. later daveo

Thanks! What I do is pump all the fuel out at the end of the day. Would this accomplish the same thing?

Jack

No, you need to pull the fuel line off, or pinch it while the engine is running. The strange thing about 4 strokes though, it has never made a difference for me whether I run the fuel out of it or not. 4 strokes rely on a little bit of "blowby" from the top of the piston, past the ring, and down into the crankcase. There is only oil down in the crankcase after flying. 2 strokes, however, have fuel running through the crankcase before it gets to the top of the piston. That means that unless you burn the fuel out of them each day, the alcohol in the fuel will attract water, and cause the bearings to rust. Bearings are high carbon steel, so they can actually rust overnight if enough water gets to them.