I'm in the process of reviving a 1977 Mercury 850 that's been in storage for 30 years. I have replaced stator, trigger, fuel lines, rebuilt fuel pump, impeller, replaced crusty engine wiring, cleaned carbs, replaced needle and seat. Engine runs well at medium to high speed, but idles rough, stalls when going into gear, and chugs/surges at ~ 5 mph. Have tried adjusting mixture screws but it hasn't helped (but I can make it worse).
My SELOC manual doesn't give much info about how to diagnose a broken or poorly-seated reed.
=> Does the symptoms sound like it could be a reed problem?
=> Is there an easy way to determine if it's reeds? (without disassembling the engine).
From what I've read, it sounds like the reeds in this series of engine are located around the crankshaft (vs newer series where they are behind the carbs).
=> How big of a job is it to replace reeds on the '77 850?
My SELOC manual doesn't give much info about how to diagnose a broken or poorly-seated reed.
=> Does the symptoms sound like it could be a reed problem?
=> Is there an easy way to determine if it's reeds? (without disassembling the engine).
From what I've read, it sounds like the reeds in this series of engine are located around the crankshaft (vs newer series where they are behind the carbs).
=> How big of a job is it to replace reeds on the '77 850?