120 HP Mercruiser i/o stalls and no restart

[skippy116]

Hi, this is approximately a repost with rewording... I have had no response for a week or so.<br /> I recently had a valve job done. I got the thing back started it up beautifully with no throttle. It purred like a kitten in idle for about 90 seconds and then quietly died- no cough, burp, or anything like that. Its as though the key was switched off. When that happens, I cannot restart it. I've tried disconnecting the wire from the coil at this point, and the spark is ok. I've tried removing the fuel line from the carb, and turning it over, and it squirts ok.<br /> If I squirt some fuel into the carb, I can get it to fire a little bit and sometimes it runs a few seconds. But not until I give up in frustration and return the next day can I get it to run for any length of time (90 secs max).<br /> When I jimmy the throttle back and forth with the engine off, I get squirts of fuel into the carb. <br /> I'm stumped- any ideas? Serial # is 3886441 if that matters.<br /> Thanks.

 

[lowshovel1]

Re: 120 HP Mercruiser i/o stalls and no restart

it is possable your choke needs an adjustment---FIRST I would pull spark plugs and let us know what they look like.

 

[skippy116]

Re: 120 HP Mercruiser i/o stalls and no restart

I pulled the plugs and compared them to a sheet of common spark plug conditions, and they look great- just like the "normal" ones.

 

[lowshovel1]

Re: 120 HP Mercruiser i/o stalls and no restart

still sounds like a fuel problem to me,is the choke opening to far to soon,?--------maybe someone else here has some idea???

 

[skippy116]

Re: 120 HP Mercruiser i/o stalls and no restart

You're a good person lowshovel1, but even the mechanic gave up on it. Now it sits in the driveway as it has for months...

 

[Don S]

Re: 120 HP Mercruiser i/o stalls and no restart

but even the mechanic gave up on it. Now it sits in the driveway as it has for months...

Sounds like you have a "Mechanic" problem more than a mechanical problem.<br />For any mechanic worth his salt to give up on a problem like that is rediculous.<br /><br />You have to have 3 things to run an engine, fuel, air (compression), ignition.<br />You say you have spark, did you check to make sure you have spark at each plug after it dies? Might try that.<br />When the engine dies, if you pull the flame arrestor off the carb can you look into the carb and see gas squirting from the accelerator pump when you operate the throttle. <br />Is the flame arrestor clean so it can breath?

 

[achris]

Re: 120 HP Mercruiser i/o stalls and no restart

Here's a curly answer for a curly question. It sounds like it's losing spark as the engine gets slightly warm. Check that the disributor is grounded properly. I have a 4.3LX that was losing revs at the top end when it was new. It took me (after the mechanic AND the state Merc rep gave up on it) 4 months to find it. It was a bad ground to the distributor.<br /><br />Chris............

 

[lowshovel1]

Re: 120 HP Mercruiser i/o stalls and no restart

If a mechanic gives up before your boat is running he ought to find another profession!! Now I know thats not going to solve your problem,I am not a marine tech. but there are a lot of people that post on this board that can and from my expeirence will help with your problem.Have you replaced all fuel related filters? if not, that would be my next step----then check fuel preasure from fuel pump to carb.anyone else have some in put----feel free to jump on in.