electric choke

[SS POKER]

i have a 84 470 mercruiser 170 hp. my problem is that the choke is not working properly. when i start the boat the butterfly stays decent then all of a sudden creeps fully open make the motor run like a raped ape. i have to manually shut the butterfly to calm her down. i took the choke off and inpsected the choke coil but not sure if it was okay or not. Any ideas???

 

[Kainon]

Re: electric choke

sounds like its working properly. You may need to get the carb adjusted properly which is done with the engine warmed up, in the water and in gear.

the choke only needs to be closed when the engine is colder and requires more fuel

by closing the butterly you are causing the engine to suck in MORE fuel.

there's a few postings on here on how to properly adjust the carb, and you may also need to adjust the throttle cable AFTER
you get the idle set correctly, people sometimes adjust the cable to get the idle where they want it but thats not the way.

 

[Fishermark]

Re: electric choke

when i start the boat the butterfly stays decent then all of a sudden creeps fully open

Like Kainon says, the good news is your choke works perfectly. What you describe is exactly what it is supposed to do.

The bad news is you have a deeper problem. When was the last time you did a complete tume up? Start there - but at some point you are probably going to need to rebuild or replace the carb as well.

 

[SS POKER]

Re: electric choke

Like Kainon says, the good news is your choke works perfectly. What you describe is exactly what it is supposed to do.

The bad news is you have a deeper problem. When was the last time you did a complete tume up? Start there - but at some point you are probably going to need to rebuild or replace the carb as well.

i haven't had this bad boy tuned. neighbor lady gave me the boat. it was her late husbands. free boat cant beat that. figured id get the dam thing runnin ya know NEW TOY FOR ME! but like i said probalem she starts then all of a sudden throttle creeps up and then before ya know it RPM SKY ROCKETS how do i get that back down so i can properly tune her??

 

[Don S]

Re: electric choke

i have a 84 470 mercruiser 170 hp. my problem is that the choke is not working properly. when i start the boat the butterfly stays decent then all of a sudden creeps fully open

Chokes are supposed to open up as the engine warms up. That is how they work.

makes the motor run like a raped ape. i have to manually shut the butterfly to calm her down.

Can you put that statement into some words that describe what the engine is doing. Have never seen a raped ape :facepalm:

Calm her down? All excited or what ?????

 

[SS POKER]

Re: electric choke

i haven't had this bad boy tuned. neighbor lady gave me the boat. it was her late husbands. free boat cant beat that. figured id get the dam thing runnin ya know NEW TOY FOR ME! but like i said probalem she starts then all of a sudden throttle creeps up and then before ya know it RPM SKY ROCKETS how do i get that back down so i can properly tune her??

i have replaced coil, wires, plugs, points, rotor. So im gettin closer now stummped how to back the idle down or adjust the carb she hasn't ran on water for a few years im guessin. LIke i said it was a free gift from the neighbor lady. HAHA

 

[SS POKER]

Re: electric choke

Chokes are supposed to open up as the engine warms up. That is how they work.



Can you put that statement into some words that describe what the engine is doing. Have never seen a raped ape :facepalm:

Calm her down? All excited or what ?????

lol don sorry...idle speeds up to almost 3200 like the motor is goin to blow. only way to back this down i found is to close the choke. in a sense sufacating the engine.

 

[Don S]

Re: electric choke

All you are doing when you close the choke plate like that is cutting off the air supply and flooding the engine so it slows down.
Sounds to me like your throttle cable is way out of adjustment and holding the throttle plates open.
When you bring it back to idle, the throttle cable should lightly push the linkage up against the idle speed screw and cam.

 

[Kainon]

Re: electric choke

lmao, Congrats and Welcome!!

Lets say the engine is tuned up and you have fresh gas.. and it still did this.

If that was my boat and I was starting it when I heard the RPMs start coming up I would actually grab the throttle control put it in NEUTRAL ONLY (actually you want to do this before starting the engine ) then you simply give it a little more throttle.

And you do this because the throttle arm on the carb has a screw for setting the idle, this PUSHES on a small metal peice (CAM) thats shaped so that when the choke is closed it sets the idle HIGHER, now when you move the throttle control and give it a little more your actually getting that screw OFF that "cam" and lets it kinda spring or return to its normal position. you then return the throttle control to neutral and the engine should THEN be at its normal idle RPMS.

make sense? hope so..

 

[Don S]

Re: electric choke

Here is some additional info on adjusting the throttle cable.

 

[SS POKER]

Re: electric choke

lmao, Congrats and Welcome!!

Lets say the engine is tuned up and you have fresh gas.. and it still did this.

If that was my boat and I was starting it when I heard the RPMs start coming up I would actually grab the throttle control put it in NEUTRAL ONLY (actually you want to do this before starting the engine ) then you simply give it a little more throttle.

And you do this because the throttle arm on the carb has a screw for setting the idle, this PUSHES on a small metal peice (CAM) thats shaped so that when the choke is closed it sets the idle HIGHER, now when you move the throttle control and give it a little more your actually getting that screw OFF that "cam" and lets it kinda spring or return to its normal position. you then return the throttle control to neutral and the engine should THEN be at its normal idle RPMS.

make sense? hope so..

that makes sense chief! ill try when i get home from work. i backed that idle screw out all the way this weekend to see if that was the problem, but didn't notice any change. HAHA this is my first big boat. i have a 14 footer aluminum with a 7 hp johnson lol so im kinda treddin on new water here. lol but eager to learn this new toy "470 mercruiser"

 

[Fishermark]

Re: electric choke

she hasn't ran on water for a few years im guessin.

Since you mention this is the first boat you have had with an I/O I have to ask -- are you supplying water to the outdrive while you are doing this running of the engine?

 

[SS POKER]

Re: electric choke

Since you mention this is the first boat you have had with an I/O I have to ask -- are you supplying water to the outdrive while you are doing this running of the engine?

yes i am...have muffs on and makin sure water is gettin to her. LOL ive done my research so far.

 

[Don S]

Re: electric choke

Did you see my pictures of how to adjust the cable?