Mercruiser 140 ignition/starter wiring issues

[cutlass185]

I'm having an issue with my boat, last week when starting the boat the starter seemed to be sticking open after the boat started. After going for a 20 minute ride in some pretty large waves we shut the boat off. Upon restart the starter wouldnt engage the flywheel so the issue was investigated, the long starter bolt had broken so the day on the water was done..... the next day i drilled the broken bolt out and got new ones, went to run it in the driveway and the starter engaged into the flywheel for a fraction of a second, I turned the key off right away and the current wouldnt quit, the stud on the battery actually mented off while i was trying to loosen the wing nut. I took the starter off and had it tested, wasnt working so i replaced the solenoid, tried it again, same issue. I replaced the engine mounted solenoid this morning and went to install the battery cable and it sparked right away so Im not sure whats going on, I thought maybe the ignition switch was bad but i pulled the fuse and it still sparked as soon as i touched the battery...... anyone have a suggestion i could try? thanks!

 

[dubs283]

Re: Mercruiser 140 ignition/starter wiring issues

sounds like you have a ground issue, where all the battery voltage is going to ground, this is why the battery post melted. a lot of amps and heat

did you replace the entire starter or just the solenoid on the starter?

you should go through the entire starting system and check for clean and tight connecions on everything

there is a starting issue troubleshooting guide in the adults only sticky that you should give a read

 

[APPALOOSA2]

Re: Mercruiser 140 ignition/starter wiring issues

I say the bendix did not return after starting and stayed engaged and thats what broke the bolt off the starter to begin with.
I would take the starter a part and if it looks good in the windings & armature I would replace the solenoid and try it.

Make sure your key is not sticking in the start mode.

All else fails replace the whole starter.

 

[cutlass185]

Re: Mercruiser 140 ignition/starter wiring issues

I did only replace the solenoids. Tonight I pulled the starter and connected a jumper cable from the front hoist location on the motor and clamped the other end to the mount hole on the starter. The starter engaged and disengaged perfectly, no current after turning at all and when I connected the neg battery cable there were no sparks. the whole situation has me confused, even with a faulty ground I don't see a reason for current to be continual. I could see if a power wire was grounding out on the block but the pos running from the battery to the starter isnt grounding out and I dont know what the pos running to the dash would ground out on..... I will trace the second pos wire tomorrow, thats really the only thing that makes sense to me. I'll apologize up front for this probably riduculous question, but theres not a relay anywhere for the ignition is there? I can see if there was and the poles were fried then possibly there could be a false positive. Thanks guys!

 

[proxyx]

Re: Mercruiser 140 ignition/starter wiring issues

weak battery, battery-to-starter and main ground cables having too much resistance will drop the voltage on the starter and it won't engage. Keep in mind you're testing without a load, any half-dead starter will work.
Check battery/starter voltage while cranking, if drops to ~9V, starter or cables need serious attention.

 

[jtybt]

Re: Mercruiser 140 ignition/starter wiring issues

What appoloosa said. The bendix is being held in the flywheel which pulls the linkage to the solenoid and keeps the high amp connection in contact.

 

[proxyx]

Re: Mercruiser 140 ignition/starter wiring issues

the problem description is a bit ambiguous. Holding the bendix (jamming I assume) indicated lack of proper clearance between the cog wheel/flywheel. You can shim that.
No spark would be separate issue after starter is fixed. There is a solenoid (cutlass... if u ask) engaging a bendix solenoid usually where the main resettable 50Amp fuse is. Follow yellow/red wire from solenoid. Btw. fried-shorted alternator rectifier could be the cause as well. I'd fix one problem with starter first and then go to the spark issue.

Look at the schematics, break up circuits into smaller ones (disconnect), separate them and check one by one.

 

[bruceb58]

Re: Mercruiser 140 ignition/starter wiring issues

sounds like you have a ground issue, where all the battery voltage is going to ground, this is why the battery post melted.

No...its not a ground issue. This statement is just plain wrong.

 

[King Size]

Re: Mercruiser 140 ignition/starter wiring issues

So the original starter that had the bolt break off, bye chance was it a smaller one then the original? And i will guess it did not have a front bracket, that connects to the block?

If i am correct the problem of a broken bolt will continue till a front bracket is made and installed.

Now to the problem gear not retracting back is cause by the after market starter, may need shimming, and the ones now are coming with shims.

 

[cutlass185]

Re: Mercruiser 140 ignition/starter wiring issues

So the original starter that had the bolt break off, bye chance was it a smaller one then the original? And i will guess it did not have a front bracket, that connects to the block?

If i am correct the problem of a broken bolt will continue till a front bracket is made and installed.

Now to the problem gear not retracting back is cause by the after market starter, may need shimming, and the ones now are coming with shims.

I believe it is the original starter in the boat but I think it was rebuilt and the solenoid replaced. The block bracket wasn't in place, whoever serviced the starter in the past had moved the end cap 180 degrees so the bracket bolt was on the bottom of the starter, I swapped it around so its in the right position now.

Its possible the bendix isn't disengaging but I'm not sure why it would turn the flywheel over for a fraction of a second then just create an open connection to the battery and not turn. Its like the starter doesnt have enough power to turn the flywheel over but won't disengage.

I pulled the plugs last week to turn the engine over by hand, it does this freely. Does anyone know where the inner starter bolt hole goes? when I drilled the remaining bolt out Idid it via mirror under the engine and a 90 degree drill and when i used a larger drill bit in the pilot hole the remaining stud followed the threads of the hole out the top, is it possible that it could be binding out the top?

 

[bruceb58]

Re: Mercruiser 140 ignition/starter wiring issues

Just to be clear...do you have both starter bolts in place righ t now and the front bracket in place? You are using starter bolts right?

 

[cutlass185]

Re: Mercruiser 140 ignition/starter wiring issues

Yes, I replaced both bolts with starter anti-vibration bolts, the ones that have the knurled (sp?) section just before the threads. When I tried to start it after replacing the solenoids I didn't have the bracket in place, I mis-placed it when I rebuilt the interior but I found it last night.

 

[proxyx]

Re: Mercruiser 140 ignition/starter wiring issues

Its possible the bendix isn't disengaging but I'm not sure why it would turn the flywheel over for a fraction of a second then just create an open connection to the battery and not turn. Its like the starter doesnt have enough power to turn the flywheel over but won't disengage.

If the starter won't crank - jamming (need some clearance between starter and flywheel teeth) or bad starter (worn bearings).
If bendix not backing up but working when off the boat - jamming again.
If you drilled new holes, possibly you cannot align/install the starter correctly. Try shimming first and/or have the starter checked by a rebuilder.
60 bucks to get starter rebuilt here. Cheap.

 

[cutlass185]

Re: Mercruiser 140 ignition/starter wiring issues

I'm going to try shimming it this morning, if that doesnt work I will take it apart and check the internals, hopefully this is the issue.

[EDIT]

I tried shimming it, still had the same results. The bendix is definately not returning. Its turning over for a second then completely stopping with the bendix out and the circuit is still trying to work.

 

[cutlass185]

Re: Mercruiser 140 ignition/starter wiring issues

I took the starter apart, i found that the collar and c-clip at the top of the shaft were missing, the coil on the shaft was hitting the base of the starter, that has to be where it was grounding out. I replaced the collar and clip and cleaned all connections in it but its still not working, its not shorting out but its not turning the engine over. now im just lost, everything inside looks good and the battery is at 12 volts on my multimeter..... any thoughts?

 

[bruceb58]

Re: Mercruiser 140 ignition/starter wiring issues

A starter can bench test fine and then not be able to operate correctly under a load. My advice is to just buy a new starter or have this one rebuilt.

 

[cutlass185]

Re: Mercruiser 140 ignition/starter wiring issues

I think I'll have to get a new starter, the bendix on this one still isn't disengaging, even with shims. Just irritates me because I cleaned all connections internally so theres really no reason for it not to work.

 

[proxyx]

Re: Mercruiser 140 ignition/starter wiring issues

I took the starter apart, i found that the collar and c-clip at the top of the shaft were missing, the coil on the shaft was hitting the base of the starter, that has to be where it was grounding out. I replaced the collar and clip and cleaned all connections in it but its still not working, its not shorting out but its not turning the engine over. now im just lost, everything inside looks good and the battery is at 12 volts on my multimeter..... any thoughts?

looks like worn brass... (typical), make sure you align a new/rebuilt one properly since you have rebored the mounts

 

[bruceb58]

Re: Mercruiser 140 ignition/starter wiring issues

I don't read anywhere that he relocated the mounts. it would be impossible to bolt this starter up if that happened.

 

[proxyx]

Re: Mercruiser 140 ignition/starter wiring issues

I said rebored not relocated, no wonder you don't read it anywhere, me too LOL.

... Does anyone know where the inner starter bolt hole goes? when I drilled the remaining bolt out Idid it via mirror under the engine and a 90 degree drill and when i used a larger drill bit in the pilot hole the remaining stud followed the threads of the hole out the top, is it possible that it could be binding out the top?