4.3 Volvo Penta idle set too high

rvlawdawg

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Dec 23, 2018
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Hi forum! I am just getting back into boating after a long hiatus. Just purchased a pristine 2004 Reinell 19' open bow. The issue is that it spent it's life at an elevation of over 8000'. I brought it down to seal level and ran it, and it runs perfectly, but idle's too high even warm. It's been a long time since I tinkered with a carb motor, so I could use some advice on getting set up for low altitude boating. Would this be a simple idle adjustment, or a change in the timing advance? I lost my timing light years ago, so if so I would need to find a shop. Thanks for your help!
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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Welcome aboard

first, make sure that your cable isnt pulling the throttle open - disconnect it if needed.

the carb should be a holley (you do not state which motor you have, there are many)

timing should be checked every year (along with other maintenance items)

carb throttle stop is a simple screw.this adjusts how far the carb throttle is open at idle

the carb idle mixure adjustments are separate, and you would adjust those as needed if you were running rich or lean at idle.

appropriate information is in the factory manual.
 

rvlawdawg

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Dec 23, 2018
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Thanks for the reply Scott. I was hoping it was going to be something as simple as an adjustment screw. Here are a few pics of the motor info for reference.
 

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alldodge

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Mar 8, 2009
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Your ID plate shows idle RPM at 500 to 650 in gear

With boat in or out of the water, have motor idling in neutral and all warmed up. Disconnect throttle cable from carb and adjust idle stop screw to about 600 rpm with an accurate tachometer.

Now adjust throttle cable so it just slides back into place on carb and able barrel nut hold bracket. Once there remove cable again and rotate barrel nut one more turn away from carb. The one additional turn when reinstalled will be pushing throttle plate against the stop.

Now take boat to a safe place on the water or keep it tied up to the dock, and shift in gear and verify tach is between 500 and 650 idling smoothly. If need be readjust idle for best idle
 

rvlawdawg

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Dec 23, 2018
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Great info guy thanks. I have only had it out once so far, but other than the high rpm at idle it ran great. I am going out the lake at the end of January, and will do some adjustments and then put some hours on her.
 

QBhoy

Fleet Admiral
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Mar 10, 2016
Messages
8,286
Hi
is this a duo prop drive ? If so, they can have their issues that can cause this.
 
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