No Vacuum Advance to distributor!

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Rhadley

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I have a 1984 4winns IL4 120HP merc. There is no vacuum advance line going to the distributor, nor do I see a fitting that a line could attach to. Ditto for the 2 barrel merc carb. What gives? Is this normal?<br /><br /> I am trying to figure out why the engine dies when I give it gas-I have to baby it through a dead spot that starts just as I start to accelerate. (shifts fine, so switch is ok. And I see a spray from accellerator pump in carb also)
 
TwoBallScrewBall

TwoBallScrewBall

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Re: No Vacuum Advance to distributor!

That distributor is mechanical advance (weighted) I believe. Advances using centrifugal force from the spinning weights. Should be no vacuum line. My first guess would be the acc pump, but you said you see spray. Might be working but not fully. I would concentrate on the carb.
 
R

Rhadley

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Re: No Vacuum Advance to distributor!

Usually you have the centrifigual weights also, but the vacuum is used for quick response. The manual I have says to remove and plug the line when setting the timing, but it covers a lot of engines.
 
TwoBallScrewBall

TwoBallScrewBall

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Re: No Vacuum Advance to distributor!

On my 1988 3.0, there's no vacuum diaphragm on the dist. I would say if there's no port on the carb and no port on the dist it's strictly mechanical.
 
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Rickles

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Mar 24, 2004
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Re: No Vacuum Advance to distributor!

I'd o'haul the carb first,checking all the passages to see they're not plugged or restricted.Make sure the float level is correct and the idle enrichment is working.Then i'd check to make sure the advance springs are intact.If they're weak or broken you'll have a hesitation on hard throttle.Hope this helps.
 
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hondon

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Re: No Vacuum Advance to distributor!

There is generally not a vaccume advance on a marine engine because vac advance is made to advance timing when the engine is coasting or running downhill to keep it from backfireing,etc.When is your boat ever running downhill?
 
A

affa

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Re: No Vacuum Advance to distributor!

Hi<br />I had the same problem with my mercarb, when I bought a carb kit and rebuild and adjusted it, it works great!<br />Affa
 
C

cobra 3.0

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Re: No Vacuum Advance to distributor!

Chances are its probably a dirty carb! Sometimes you can get lucky and just get away with putting some injector/carb cleaner in the tank and using a carb cleaner spray in the carb. If that doesn't work, the carb will need to be taken apart and cleaned.
 
R

Rhadley

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Jul 20, 2003
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Re: No Vacuum Advance to distributor!

Thanks for the inputs--I'll do a rebuild
 
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