merc inline 6 hard starting

bmmc

Cadet
Joined
Apr 15, 2009
Messages
7
1986 90hp.lately hard to start when cold.seems like there is a fine line between getting enough fuel to start & flooding.new plugs,fresh fuel (premium),120 lb all cylinders,good spark.sometimes takes 15 to 20 attempts to start.enrichment valve appears to be working properly.what is the proper procedure in using the enrichment valve to start a cold engine(time valve should be energized)?been running this engine about 10 years & never had this problem.
 

BatDaddy1887

Chief Petty Officer
Joined
Jan 18, 2009
Messages
463
Re: merc inline 6 hard starting

Proper procedure for cold start is pump bulb till hard, push in key and hold it in while starting. If it does not start right away pump bulb till hard again and try ignition without pushing in the choke (key). If you think it is flooded, tilt motor all the way up to try and spill overflow of gas out of carbs. Start the process all over again and holding in the key choke is the thing you need to do. Also check for fouled plugs. Most people say you really don't need premium gas but if that works best for you then have at it.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,036
Re: merc inline 6 hard starting

You should never be able to flood that IL6. They love lots of fuel for cold start. Maybe something is wrong with carbs? Is your fuel pump diaghram leaking raw fuel into the crankcase?
 

bmmc

Cadet
Joined
Apr 15, 2009
Messages
7
Re: merc inline 6 hard starting

had the same problem.removed the hose from the enrichment valve going to the crankcase & noticed a slow dribble from the hose.changed the valve with another I had & the flow was much better.cranked the engine & it fired right up on second attempt.cleaned the old valve with carb cleaner & blew out with air.flow increased from a dribble to a steady stream.evidently valve was gummed up.hope this helps someone
 

Lone Duck

Master Chief Petty Officer
Joined
Oct 17, 2007
Messages
868
Re: merc inline 6 hard starting

Proper procedure for cold start is pump bulb till hard, push in key and hold it in while starting. If it does not start right away pump bulb till hard again and try ignition without pushing in the choke (key). If you think it is flooded, tilt motor all the way up to try and spill overflow of gas out of carbs. Start the process all over again and holding in the key choke is the thing you need to do. Also check for fouled plugs. Most people say you really don't need premium gas but if that works best for you then have at it.
Yup ! And make sure your fast idle is wide open '
 
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