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older OS 120 4 stroke pump screw reset info

Old 06-15-2020, 09:33 PM
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bigtim
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Default older OS 120 4 stroke pump screw reset info

so a little info.
I have 2 older 120 pumped surpass engines that I am planning on rebuilding/replacing the bearings, both I got used, one is in really good condition although I suspect it needs new bearings and a cleaning because its been sitting for several years, and is really stiff to turn over, the little paint dots on the pump are intact and the back pump screw appears unmolested there is a note in the instructions that says specifically to not mess with this screw as its set at the factory, this pump I'm not worried about.

engine #2 I have torn this one down bearings were replaced incorrectly by the previous owner and were very rusty, carb appears clogged and I will disassemble and clean, the biggie is the back screw on the pump has been messed with and the old paint dots are missing, it looks as though the previous owner was having trouble tuning the engine and tried to mess with the pump,there are fixes for these older pump problems by doing a little plumbing of the fuel lines I'm not too worried about that .

is there a way to reset this screw to the correct pressure position without sending it in to a maintenance shop, we used to be able to send engines to towerhobbies but with the sale of hobbico, and the age of the engine if I can adjust it myself I will just do it myself,I did put the pump screw in the position corresponding to the depth and position of engine #1 but who knows if this is correct or not, and secondly are there any specific cautions for tearing down the carburetor or just be careful and put it back together the way you found it just cleaner than it was

Last edited by bigtim; 06-15-2020 at 09:39 PM.

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