1973 Mercury 20 hp diagram

Chris Stevens

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Mar 8, 2002
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2
Does anyone know where I can find a very simplistic diagram of the outside of a 1973 Mercury 20 hp outboard?? I need something that shows the location of all external controls (throttle, choke, forward/reverse, etc.) I have a mercury service manual for that year, but the information is very technical..I just want to know where all the controls are.
 

steverino

Cadet
Joined
Mar 3, 2002
Messages
23
Re: 1973 Mercury 20 hp diagram

I have a motor exactly like yours. What exactly are you trying to figure out?
 

Chris Stevens

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Joined
Mar 8, 2002
Messages
2
Re: 1973 Mercury 20 hp diagram

Steve, I'm trying to figure out where the throttle is (is it in the tiller handle?), where the forward/reverse is, and really just how to start and use this engine properly. Quite frankly, I don't know a thing about outboards (or engines in general) I'm used to rowing around in a dory), and I'm trying to get the basics about outboard operation, particularly the starting, stopping and shifting procedures for this motor.
 

Chinewalker

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Joined
Aug 19, 2001
Messages
8,902
Re: 1973 Mercury 20 hp diagram

Hi Chris,<br /> Here we go... looking at the front of the motor, on your left, on the side of the motor is the shift lever. There should be some letters on the motor, nearby, F-N-R for forward, neutral and reverse. On the front face, left to right, there should be a choke knob, kill switch button (might be on the side, near the shifter, as they moved it at some point in the early 1970s), and the fuel connector fitting. Connect the fuel tank fitting here (push and twist), prime the queeze bulb in the fuel line until it won't squeeze easily. The throttle is indeed on the end of the tiller handle. With the motor in neutral, you can advance the throttle to the stop (when it won't advance any more), pull the choke (for cold motor only), pull the recoil handle out until resistance is felt, then give 'er a yank! Make sure the motor doesn't race - be quick to reduce throttle if it starts to rev up. Shifting should only be done at slow idle - as slow as it will go without stalling - don't depend on the "shift" zone marked on the throttle handle (if the marks are still there). Check for a strong stream of water coming out the "pisser" in the rear, left (from your vantage point) side of the motor. Some water may also come out of the slots in the upper portion of the motor leg.<br /> They're a good strong motor, but you have to take care of them (like anything else). If the motor is new to you and you're unsure of the service history, I would take it to a Merc service guy and have him install a new water pump impeller and check the lower unit oil.<br />- Scott
 

Chinewalker

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Joined
Aug 19, 2001
Messages
8,902
Re: 1973 Mercury 20 hp diagram

Hi again Chris,<br /> If you want to get an owner's manual, they often turn up on eBay or you can order one from Grubb's Marine (www.oldmercs.com). That will have a much more "user friendly" guide to general usage stuff than a service manual...<br />- Scott
 
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