1986 Yamaha 200hp Idles high.

[kbmsound]

So i got this 1986 Yamaha 200hp on a Wellcraft 230 Sportsman as part of a trade. I didn't know what condition the motor was except it had good compression, and was not missing anything. I finally got it to start today after replacing plugs, water separator, and fuel lines and primer bulb with brand new boat fuel on a clean tank. I am pretty sure it needs a carb rebuild. The issue is that when I start it, it starts to rev up and stays there. I have to cut it off because it has a pretty large water leak at the starboard thermostat gasket. Now, at the helm, I have a binnacle style lever ( i think that's what its called) so the key sits separate below with the kill switch and the choke switch ( which does nothing at the moment). I have no other levers to play with as other control boxes have that lever on top for starting when cold. I have tried starting it both with choke on and off, does the same thing every time. Is this a carbs issue, or is there something else affecting it?

 

[rjcamel2355]

Possible a carb issue, but it's also possible you may need to adjust the throttle cable/idle adjustment (Look at the motor where your throttle cable goes to the linkage) is there a stop? is it sitting on the stop in neutral? If you could post a picture of the engine with the cowl off where your cables go in, that would help. Also a serial/model number would be great.

 

[kbmsound]

Possible a carb issue, but it's also possible you may need to adjust the throttle cable/idle adjustment (Look at the motor where your throttle cable goes to the linkage) is there a stop? is it sitting on the stop in neutral? If you could post a picture of the engine with the cowl off where your cables go in, that would help. Also a serial/model number would be great.

I will try to get a pic up. The motor is a 200ETXJ

 

[rjcamel2355]

I could be completely wrong here, but it looks like the stop is pressed against the block (assuming the throttle is currently in neutral). Whats with the copper colored wire ran to all the carbs? That looks a little odd to me. All it would take is one of the carbs to be cracked open to cause the high idle, so if that wire is hanging/catching that'll cause it. Pull the plastic cover over the front of the carbs, and see if any of them are cracked open, throw up another picture if you have doubts whether they are or not.

It LOOKS to me (judging by the picture) that the carbs aren't closed all the way, look at the plastic "lever" and you can see where the throttle lever on the carbs isn't touching it, and it should be at "idle". Just above the choke solenoid is where I am talking about.

 

[kbmsound]

I could be completely wrong here, but it looks like the stop is pressed against the block (assuming the throttle is currently in neutral). Whats with the copper colored wire ran to all the carbs? That looks a little odd to me. All it would take is one of the carbs to be cracked open to cause the high idle, so if that wire is hanging/catching that'll cause it. Pull the plastic cover over the front of the carbs, and see if any of them are cracked open, throw up another picture if you have doubts whether they are or not.

It LOOKS to me (judging by the picture) that the carbs aren't closed all the way, look at the plastic "lever" and you can see where the throttle lever on the carbs isn't touching it, and it should be at "idle". Just above the choke solenoid is where I am talking about.

You are correct about the stop being against the block. That is how it is supposed to be?. I jerry rigged that wire linking the carbs because the link that connects all the carbs together for accel broke off. I will remove the wire and see if the carb returns to the idle position. Good catch, rjcamel2355

 

[rjcamel2355]

That should be touching at idle, as that controls the acceleration, as you can see it's not touching. That's the cause of your high idle. That's what I was getting at earlier.

 

[kbmsound]

That should be touching at idle, as that controls the acceleration, as you can see it's not touching. That's the cause of your high idle. That's what I was getting at earlier.

You are correct sir. I removed the wire, the center carb was just slightly cracked open, and it returned to idle. Fired right up and purrs like a kitten. Amazing how it sounds despite being an 86 and unknown how long its been sitting. Tomorrow I will let it run longer on water and run some seam foam through it. Now i just have to replace thermostats and gaskets, water impeller and lower unit oil, and the throttle cable which is seized. Thanks so much rjcamel 2355, you have saved me a lot of stressing.

 

[rjcamel2355]

No problem! Glad I could help, can't beat the way an old 2 stroke sounds bud. Good luck, and let me know if I can help any further!