mercruiser 4.3lx not re-starting

[andyclarke]

hi, i was out in reasonably heavy seas at the weekend in my stingray 657zp and took a few hard landings, one of them pulled the kill cord off as it was attached to me. we were able to restart the engine but it only ran for 50yards then died never to be restarted, lucily there was a rescue boat passing at that very time which towed us back in, while we were being towed(half an hr or more)we tried various things but couldnt get the engine to re-start, we checked for a spark and for a flooded engine but nothing seamed to work.
i dont know if it was the heavy landings knocking something loose or the kill cord being pulled or just something that needs resetting? if anyone could give me any pointers it would be much appreciated.
thanks.

 

[cooter2506]

Re: mercruiser 4.3lx not re-starting

Did you have spark? Did you have fuel? It says you checked but didnt really tell us if you did or did not?

 

[andyclarke]

Re: mercruiser 4.3lx not re-starting

we took out the spark plugs to see if it was flooded and give it chance to evaporate off, there was some fuel on the plugs so we left them out for 20mins or so, while they were out we put one on the block and turned it over to see if there was a spark, there was, althought i dont know how strong it was as i was the one on the starter key not the plug.(i have read about weak sparks)
the reason we thought it may be flooded was because the kill cord came off while it was running and so we assumed still pumping fuel.
i have also read about things coming loose in the electrical system. (and we did land pretty heavy, its probably good for it but im new to this game)
any pointers would be welcome.

 

[Bondo]

Re: mercruiser 4.3lx not re-starting

there was some fuel on the plugs

Ayuh,... Replace the plugs with New,+ Try it...

 

[fjcruiserchaparral]

Re: mercruiser 4.3lx not re-starting

What caused the engine to flood? I think I had the same case last saturday, I was underway around 3k RPM, not fast becasue of the big waves then suddenly the engine bogged down and died. Tried starting but to no avail, pumped the throttle to give it a little gas but still wont start, started to smell gas. I tried starting from time to time about 15 mins interval. after drifting for an hour it finally started. Im still figuring out what caused this.

 

[Fix'em]

Re: mercruiser 4.3lx not re-starting

Is the engine carburated? If so, I've seen (and experienced) some situations where some really violent wave landings can upset and jam the floats or even stirr up some of the old crap settled in the bottom of the fuel bowl to plug the jets.

 

[andyclarke]

Re: mercruiser 4.3lx not re-starting

thanks, i will replace the plugs to be sure they'r good.

the reason i thought the engine was flooded was because i pulled the kill cord at about 3000rpm and guessed there was still fuel being pumped into the engine after the spark had gone(sounds like a relationship)

the engine is carburated, i will take the carb off and look at it, to see if the floats are stuck. there shouldnt be any crap in the fuel as i just filled it up with ?80 of unleaded on the way to launch the boat(so plenty in there for next time)
but like you said it could be crap from in the area where the floats sit.

i was also trying to restart for some time but had the worry that the battery might die then id be stuck, may carry a spare?

thanks for the pointers

 

[andyclarke]

Re: mercruiser 4.3lx not re-starting

just one point to add, i can also smell fuel for some time now, cant find any leaks but can definelty smell petrol.
is some normal?

 

[Bondo]

Re: mercruiser 4.3lx not re-starting

i can also smell fuel for some time now, cant find any leaks but can definelty smell petrol.
is some normal?

Nope...

 

[andyclarke]

Re: mercruiser 4.3lx not re-starting

i didnt think so.... i should look into it more, fuel is a thing not to be wasted unless its getting burned in the engine!

does anyone know where i can find a download of the mercruiser manual for the 4.3lx (1992)? ive found links to many manuals but not the correct one, and the one i thought was the right one only had the first few chapters convieninetly ending before the carb's.

thanks.

 

[andyclarke]

Re: mercruiser 4.3lx not re-starting

the problem fixed itself....
i spent the day tinkering with the engine, but to no avail.
still just turned and turned over. i looked over electrics and tapped the carb to free the floats(if they were stuck).
then i called an expert, he said look at the spark plugs for fuel and a spark to start.
pretty straight forward, i had already checked this at the time of the breakdown two weeks back but thought id check again.
took one plug out, wet with fuel. got the engine turned over while i held the spark plug on an engine mount to check for a spark when a backfire came out of the open cylinder right next to my head! but the engine tried to fire so stunned i put the plug back in and sure enough i started.....
then the guy at the boat yard wanted to lock up and go home so thats where i left it.
i plan to go down this weekend and run it on muffs for a while before putting it in the sea for a test.
all being well(and sunny) we will go fishing