Recall that the carb kept needing tuning every time I took it out. Recall further, I screwed this engine up when I rebuilt it trying to get better performance, when it already was fine. It was my first RCGF, a few years old, and needed a cleaning anyway., so I rebuilt it and the carb, and it's never been right since. Joe Nelson of RCGF, and I are sure it's the carb.
Well, the carb went back to its antics and ran great WOT and most of the time at half, but idle dropped to a high idle probably around 3500, then would slowly step down and then stop over aminute. Am I crazy thinking an engine should be able to sit at idle indefinitely? In my last post I noted I purchased a Walbro WA-80 carb, which is no longer in production. I found two new ones at about the same price on eBay. On Flying Giants a poster noted that a smaller carb works better for these small engines, so instead of the stock 10mm, the WA-80 is about 7.1 mm. They note far better performance. So I took the engine off the airplane, and removed the carb. As soon as the new one gets here I will install and put this thing back together. I can't wait to get this engine back to it's flying performance!
I also slowed the servo to about 0.7s, and honestly, it provided a nice smooth progression from idle to WOT. I may do this on all my gassers. It lows the transition in the carb preserving the vacuum, as opposed to jamming it forward and losing vacuum causing the engine to lean as you need more fuel.
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