automatic choke?

[jimmyz1]

Well I took the newly purchased boat for a run today and the motor (60hp merc. 1987) ran great. The problem was getting it started. It's has an automatic choke which makes a click when you depress the key. What does and how does it work please? I had to take off cover and hit the carbs with fuel direct to get it to start. When the cowel was off I noticed that when the controls are in the start position the butterfly flaps where not close all the way. The other motor I have is a 25hp johnson pull start, but when you choke it, it closes all the way. Am I missing something here? Should they be closed all the way? Thanks

 

[CharlieB]

Re: automatic choke?

A Merc w/ an automatic choke?

Most the Merc have the choke switch built into the key switch, turn the key ON, push the key IN and hold, it auto turns the choke OFF when you release the key

 

[woody66912]

Re: automatic choke?

it's not a choke per say. it's a primmer it gives a shot of fuel to the intakes.so the plates you are seeing are throttle plates..and if they are not closed when the throttle is returned to idle you need some adjustments done.or most likely you need your carbs rebuilt and adjusted.

 

[jimmyz1]

Re: automatic choke?

it's not a choke per say. it's a primmer it gives a shot of fuel to the intakes.so the plates you are seeing are throttle plates..and if they are not closed when the throttle is returned to idle you need some adjustments done.

So I'm just a little confused. So actually there is no choke. The pushing of the key shoots fuel into the intakes. So do you need to hold it down when turning the key and cranking? The plates are open when the fast idle lever is in the up position as it and they should be be to start. The shift lever stays in the neutral position. So if I want to start the motor I should maybe:

1. Push key in a few times

2. crank motor and when it fires maybe then lift fast idle (throttle) lever

This is my first turn key outboard, my others are pull out choke, prime bulb, pull rope, motor starts. Motor starts to slow down, push in choke.

My confusion is coming where the valves are open, I thought it's easier to start a cold motor by reducing amount of air it draws in and sucks more fuel when choked?

Thanks

 

[emckelvy]

Re: automatic choke?

Don't get too "wrapped around the axle" on how the choke actually works. Suffice to say that the only time the enrichener aka "choke" works is when the key is pushed in as the motor is cranking.

It really does no good to push the key in before cranking the motor. Although you've built up a tiny bit of fuel pressure by pumping the primer bulb until it's hard, there's little or no priming action going on if you activate the 'choke' without cranking over the motor.

A friend of mine had a 3-cyl 90 hp Merc on a ski boat. He'd bought it with a 'blown' rod, and rebuilt the powerhead. He had a lot of trouble getting it to start until he figured out that if you pushed on the key to 'choke' then cranked over, it wouldn't go.

If you waited until you were cranking the motor over THEN pushed in the key, it fired off lickety-split! Go figure. Just like a previous poster stated.

I'm thinking that would be the best procedure for yours as well. Once the motor has started to crank over, it's developing pressure pulses in the crankcase and the fuel pump is now generating fuel pressure. So, when you press the key in to "fire off" the enrichening circuits on the carbs, they're squirting fuel quite nicely.

So don't 'choke' or 'enrichen' at all until you start cranking the engine over.

Make sure you've pumped the primer bulb up firmly and raised the Fast Start lever to an appropriate speed for fast-idle starting.

Hold that key in until the motor fires. Run at a fast idle (not real fast, enough to keep the motor from dying). If the motor fades away like it's running out of gas, press the key in for just a second or less. If the motor picks up again you'll know that's what it wants.

Just about every motor has its own "starting drill". Once you figure it out, and do that consistently, you'll probably have much greater success in getting 'er started every time.

HTH & let us know how that works out..........ed

 

[jimmyz1]

Re: automatic choke?

WOW! That was much easier. I pumped bulb, turned key motor fired/died immediately. Turned key again, pushed in on key and lifted and lowered fast idle twice and she fired right up. It was a matter of a few seconds. That makes me feel better. Nothing worse than being at the ramp trying to figure out how to start your new motor.

Thanks for all the tips guys.