Mercruiser 120 Wont Start

Tuaca

Recruit
Joined
Jul 23, 2005
Messages
4
Well just last week took my boat (83 conroy) out that I had recently bought a few weeks prior and the first time we took it out it ran fine then the secong time we took it out after about 45 min of just cruising around it started to lose rpm's and cutting out itwould be at about 4100rpm then look down when it stared acting up was at around 3500rpm so I killed it and we took a little swim started back up ran fine for another 30 or so minutes so I took it home and replaced plugs and wires took it back out and problemn still there so I was heading back to boat ramp and just out of the blue it dies and wouldnt start.So far I have replaced the points and condenser with the pertronix electronic ignition conversion,cap,rotor,plugs&wires checked if I was getting spark to plugs and I was also checked fuel to carb and when I would push the throttle down I see fuel. Motor acts like it wants to start but never does im kinda of at a stand still here im out of ideas.Any advice is appreciated as im new to boats also the serial # of motor is 6348136 if that helps any. Thanks in advance
 

Trent

Captain
Joined
Nov 17, 2001
Messages
3,333
Re: Mercruiser 120 Wont Start

With a voltmeter measure the voltage at the + side of the coil. You need 9.5 volts to run correctly.
 

Trent

Captain
Joined
Nov 17, 2001
Messages
3,333
Re: Mercruiser 120 Wont Start

Check voltage at the coil while cranking... What is it then.
 

waterone1@aol.com

Lieutenant Junior Grade
Joined
Oct 10, 2004
Messages
1,235
Re: Mercruiser 120 Wont Start

You saw something squirting out in the carb....are you sure it is gas...and not water ? You might try pulling the gas/water seperator and dumping the contents into a glass jar, look for any seperation and verify it is all gas.
 

Tuaca

Recruit
Joined
Jul 23, 2005
Messages
4
Re: Mercruiser 120 Wont Start

Ok today I checked the voltage at the + side of coil and it only read 4.5 and while cranking it it was in the low 9's as far as overheating the temp gauge read about 150-160
 

Tuaca

Recruit
Joined
Jul 23, 2005
Messages
4
Re: Mercruiser 120 Wont Start

Well after a few more days of tinkering checked gas all is well still just on the verge of starting im not sure what to do?
 
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