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OS 61 "SF"

Anyone have the low and high RPM limits for this engine. It's does ok from mid to full throttle but the idle is rough and dies.I've adjusted the low end and just can't find that rite spot.The low end is not like my other engines.The little offset screw that rocks the plate back and forth don't have a lot of movement.There's no air leakage. The engine doesn't have much time on it.Got it and replaced the bearings and low end adjustment assembly. I put the new one in like the old one came out but wondering if something is arye. I need to get a tack to see exactly what r's it's turning but I'd guess around 5000. Help Walt

Reply to
TX_QBALL
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If you are only getting 5000 RPM, something is wrong. This engine easily exceeds 12K when properly adjusted. It seems likely that you are running way too rich. My 61 SFs aall did a "4-stroke" idle at less than 2000 RPM without difficulty.

I use a 13X6 prop on mine, and it runs great. First adjust the high end by peaking it lean and backing off abou 300 RPM. To adjust the idle, use the pinch test. With glow heat on, pinch off the fuel while it is idling. If the engine speeds up much before quitting, it's too rich. If it slows and stops, it's too lean. You should get a small increase in RPM only.

Once adjusted, remove glow heat. If it slows down a great deal, then you have a bad glow plug.

Jim - AMA 501383 (remove NOSPAM to reply)

TX snipped-for-privacy@webtv.net wrote:

Reply to
James D Jones

Good advise Jim. However your last comment regarding the engine 'slowing when glow power is removed' should include, in addition to a bad glow plug, possibly bad fuel .

Happy Flying, Mike

Reply to
Mike

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