ORIGINAL: harryangus
OPJOSE,
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You raise an important fact. I have 3 OS engines and I use the same fuel and flew all 3 the same amount of time.</p>
However only one (the LA) has a lot of stains and that stain is mostly on the top of the cylinder.</p>
And that engine beeing an LA has a metallic rattling sound since the first time I started it.</p>
The hobby shop told me it was OK, and that all LA engines have this noise.</p>
I am not a handy person and I know very little about engines, I would not try to uncrew the head myself.</p>
I will ask a friend for help.</p>
Thanks,</p>
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The LA series engine have a plain main bering and this type engine will require slightly greater crankshaft end play than a ball bering engine (All engines will have some endplay although to various degrees).
All plain bering engine will demonstrate some of this rattling which most often shows up while the engine is idled down and will sound somewhat like a boiling teakettle. As the engine wears throughout its practical wear life this rattle effect at idle will get more pronounced but is not a problem in itself.
Your LHS folks were correct. I use to love the old K&B Sportster's especially the little .20 and .28's that I called the teakettles. Shoot they didn't really get good untill they rattled big time at idle.
John