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OS 91 Surpass woodruff key

Old 06-01-2014, 01:44 AM
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Default OS 91 Surpass woodruff key

I recently acquired a older version of the surpass engine for a good price but when I inspected the engine the drive washer spun freely on the crankshaft, upon further inspection the woodruff key was missing, no big deal I will order another one but I noticed on my other engines that I have(that are the same older type surpass) that the drive washer is quite tight and would take a puller to get the washer off the crank is this typical?,

I have other larger OS 120 4strokes where the drive washer isn't so tight and I need to be careful not to loose the key when I take the prop off

is there a proper way of installing the key and washer so I don't damage the crank ?

my first guess would be to align the parts and slowly tighten a propeller until its seated but I would rather make sure the job is done correctly the engine is really clean the bearings are tight as though the previous owner had replaced them but had lost the key at some point,

I was told he had passed away so I can't find out at this point after I get this sorted out I will go though it and check the valves and see how she runs.

the engine also has great compression and by the looks of it had minimal use or was taken good care of this seems like a minor issue any tips would be helpfull.
Old 06-02-2014, 06:33 AM
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Usually, if the engine has a woodruff key, the drive washer will slide on and off with little or no pressure. Using the hands is sufficient. If it's a tight fit, usually due to congealed fuel residue, a puller will do the job. When reinstalling it, if it's still tight, then just align everything and tighten it on with a propeller or other spacer to allow the prop nut to do the job. It's hard to hurt the engine as long as things fit together smoothly.
Old 06-02-2014, 07:47 AM
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thanks Bax

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