problems with 4.3 mercruser

[produceguy]

We went out on the lake the other day and dropped her in the water,she fired right up and away we went.
I started smelling some wires burning so I shut the boat off and started looking for the bad wire.Couldn,t find it so I tryed to start her back up and head to the dock,she would start but when I put it in gear she would die and the shift cables had stiffened up.
Would a saftey cut off switch cause this to happen and would a hot wire cause the switch to react?
4.3 mercruser alpha 1 gen 1.
What's bad is my family is in from out of town so I took them out to have a good time and end up getting towed back to the dock by the sherrif. :redface:

Any input is appreciated.

 

[Oldskool]

Re: problems with 4.3 mercruser

Last year my son had a similar thing happen our our boat. Boat started to smell like rubber was burning. Engine quit and wouldn't start again. Turned out it was the upper half of the outdrive had seized up and the smell was coming from the engine coupler. Not sure if it would cause the shift cable to stiffen up.

 

[Bt Doctur]

Re: problems with 4.3 mercruser

Did you service or check the outdrive oil level?
Did you test run it on muffs to verify correct operation?
did you notice a hi temp with the smell?
If you overheated you fused the shift cable where it passes close to the exaust pipe.

 

[produceguy]

Re: problems with 4.3 mercruser

Did you service or check the outdrive oil level?
Did you test run it on muffs to verify correct operation?
did you notice a hi temp with the smell?
If you overheated you fused the shift cable where it passes close to the exaust pipe.

Yes.
Yes.
No.

 

[Bt Doctur]

Re: problems with 4.3 mercruser

Physically follow the lower shift cable to where is passes by the exaust, there should not be any melted areas.Next would be to check the drive oil level , if still full remove drive and check cable operation.

 

[produceguy]

Re: problems with 4.3 mercruser

Physically follow the lower shift cable to where is passes by the exaust, there should not be any melted areas.Next would be to check the drive oil level , if still full remove drive and check cable operation.

I checked the cable and no melted area.
I hooked up the muffs and fired it up and the shift cables are not tight now for some reson.
I gave it some gas and she dies. I did this for about 15 min and sometimes she went in gear and ran and other times she dies.
My wife seen a spark at the battery so I checked the connection and the pos side was so hot it might leave blisters on my fingers.
I felt the risers and one side was cool to touch and the other was hot, I could not leave my hand on it. Is the riser issue because it's on muffs?

I don't know if this is a piece of rubber came out of the lower unit or not but when I got out of the boat to look at the prop this was laying in the prop cavity.
View attachment 101164
View attachment 101163

 

[kentlt]

Re: problems with 4.3 mercruser

I had the same problem with my 4.3L. Last week we arrived back to the dock to see smoke coming out of the engine compartment. Turns out there was a crack in the rubber sleeve that holds the exhaust parts together, just above the point where the shift cable passes the exhaust. I didn't notice the temp gauge but am pretty sure she was hotter than normal. I replaced both port and starboard side rubber sleeves. The starboard side was in much worse shape than port.

I had not checked the gear shift as it didn't enter my head as being a potential problem. Today when we were out on the water, the gear shift was very stiff and the engine cut when I tried to go into gear. As BT Doctur had suspected, we found a melted section of the shift cable that sits against the exhaust. Looks like that may be the problem for gear changing but is there another issue with the engine shutting off? I'm not sure what this does but could it be the shift cut-out switch?

 

[produceguy]

Re: problems with 4.3 mercruser

I do know that if your cable is bad the cut off switch will be triggered.
I had to replace the lower shift cable about 6 months ago because of that very reason.

 

[kentlt]

Re: problems with 4.3 mercruser

...repeat post (now deleted) - ignore

 

[produceguy]

Re: problems with 4.3 mercruser

Anybody else have any input on this?

 

[dubs283]

Re: problems with 4.3 mercruser

electrical heat = resistance

check ALL battery positive AND negative connections at starter/engine block for loose/corrosion

is your alternator overcharging?? (volt guage showing more than 14.5 volts)

 

[produceguy]

Re: problems with 4.3 mercruser

No the gauge is normal. I will check all the wireing later tonight when it's only about 110 and not 117 degrees.
When the muffs are on,would that cause one riser to run hot and what might be causing her to stall when but in gear?
Now, sometimes she stalls and sometimes she doesn't, should this rule out the cut off switch?

 

[dubs283]

Re: problems with 4.3 mercruser

the only way to rule out the interrupt switch is to watch it when shifting into gear, a worn cable or even misadjusted cable can cuase it to engage improperly

another possibility is the carb loading up at idle and when a load is put on the engine it dies, check fuel flow at the primarys when idling, should be ZERO fuel going through the venturis

 

[produceguy]

Re: problems with 4.3 mercruser

the only way to rule out the interrupt switch is to watch it when shifting into gear, a worn cable or even misadjusted cable can cuase it to engage improperly

another possibility is the carb loading up at idle and when a load is put on the engine it dies, check fuel flow at the primarys when idling, should be ZERO fuel going through the venturis

Thank you.I did readjust the shift cables a couple of weeks ago and this was the first time out since. I'll start their.
I have checked the carb and all seems to be good. Thanks again.