85 Merc idling

andrewkafp

Lieutenant Commander
Joined
Mar 15, 2003
Messages
1,668
I have a 1985 Merc 4 cylinder 2 stroke (Havent had it in water yet). It starts fine and is running on all 4 cylinders, but when it has the "Ear plugs" connected it tends to run rough like a Harley...<br />or a Volkswagen with extractors... Last compression test was 110,110,110,110.<br />When I inrease the throttle it tends to smoothen out more and sound better. Is this due to the fact that the exhaust is not submerged or that it has not reached running temp? It is partly under a Carport so it sound quite loud and as the exhaust is only very short it would have limited sound deadening I suppose..
 

alcan

Commander
Joined
Dec 14, 2001
Messages
2,505
Re: 85 Merc idling

I supose this sounds normal. I am surprized your not deaf. With all that racket how would you know if the thing was running good or not. Try this. Fill a garbage can full of water, put the motor in it while useing the muffs. Use both at the same time. This helps keep the neighbors friendly, it also lessens the chance that exhaust gases get sucked up the water pump and provides the correct back presure. The muffs alone are fine for flushing at idle. They also have a device called a flush muffler.
 
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