4.3LX 6 cylinder Mercruiser won't start!

[gallmond]

I was referred to this forum by a friend and he told me that you guys had great advice so hopefully someone may be able to help me out. I don't know too much about this type of stuff so any advice would be graeatly appreicated.

I have a 1996 Mercuriser V6 Alpha One 4.3LX (it is carbuerated) and I just had the spark plugs changed by a mechanic. I got the boat back from him and it drove fine for about 15 minutes. I pulled it into my boathouse and it just quit. No sputtering or anything. I tried to start it up again, it cranks but nothing happens.

After trying to crank it several times (with nothing happening) I noticed that the ignition coil was VERY hot and that it looked like it may have leaked some type of fluid out of the top if it. So I replaced the ignition coil with a new one and I still have the same problem...it cranks but it won't start.

I also noticed that the 50 amp electrical system overload protection (a red button on top of the engine) cannot be pressed in at all. I am thinking that my next step may be to replace this 50 am circuit breaker.

Any suggestions on what the problem may be the problem.

 

[Don S]

Re: 4.3LX 6 cylinder Mercruiser won't start!

If that breaker hadn't popped you can't reset it???????
If it had popped you wouldn't be able to crank the engine over.
Do you have spark? Is there an ignition fuse under the dash that may have popped? Perhaps the kill switch lanyard got pulled?

 

[Limited-Time]

Re: 4.3LX 6 cylinder Mercruiser won't start!

I was referred to this forum by a friend and he told me that you guys had great advice so hopefully someone may be able to help me out.
I also noticed that the 50 amp electrical system overload protection (a red button on top of the engine) cannot be pressed in at all. I am thinking that my next step may be to replace this 50 am circuit breaker.

Any suggestions on what the problem may be the problem.

The 50 amp breaker will only reset (push in) if tripped. Yours apparently is not. Also if your engine is turning over your breaker is OK.

As for the no start you need 3 basic things to run, compression, fuel, and ignition. Sounds like the latter is missing. If you post your engine serial number one of the techs will be able to give you direction.
BTW welcome to iboats.

 

[gallmond]

Re: 4.3LX 6 cylinder Mercruiser won't start!

Thanks Limited and Don, its great to have a forum like this! I really appreciate the help.

I believe that my serial # is OF774349. When I get home I will double check that and repost the # if it is incorrect.

The first thing I did before I changed the coil was to pull a spark plug and check for spark. There was no spark at all coming from the plug. After I noticed there was no spark, I replaced the coil with a new one. After changing the coil, I tried to crank it again and it didn't start. I didn't check to see if I had spark again after changing the coil (it was night time and too dark to see at that point). I willl double check that this afternoon and let you know.

If I check it again and there is still no spark after changing the coil...what would be my next step?

Please let me clarify a little about what I was trying to say about the breaker. The 50 amp braker (the red button) says on the side of it "press to reset". I cannot press it in at all, it seems to be stuck. I didn't know if that meant that it was blown or not.

 

[gallmond]

Re: 4.3LX 6 cylinder Mercruiser won't start!

Don, I forgot to tell you the answer to your questions: I checked the kill switch lanyard it it didn't get pulled. Also, I looked for an ignition fuse and didn't find one (maybe I looked in the wrong place or something). I looked directly behind the ignition (where the key goes in) and did not see an ignition fuse anywhere.

thanks again!

 

[Reel Poor]

Re: 4.3LX 6 cylinder Mercruiser won't start!

With the key on check for voltage at the Batt/+ terminal of the ignition coil. If you have voltage there pull the coil wire out/off of the coil and check for spark from coil.

Also unplug and check the ignition module connector for dirty/green terminals.

 

[gallmond]

Re: 4.3LX 6 cylinder Mercruiser won't start!

I'll try that Reel Time. Thanks.

 

[achris]

Re: 4.3LX 6 cylinder Mercruiser won't start!

"Press to reset" is only applicable if the breaker has tripped. When they trip the red button in the centre will be out about 3/4". Only then will pressing it reset it. Which is all irrelevant becuase the breaker hasn't tripped, you can crank the engine. Likewise the ignition fuse (in the red wire coming from the ignition key), it's ok because you can crank the engine.

In the factory service manual is a step-by-step procedure to diagnose the ignition system. I would type it here, but I don't have my manuals available where I am, sorry..... Maybe this is a good opportunity to go and buy a factory manual....

Silly question, you have check that it's getting petrol to the carb?

Chris................