Starter Run-on

[deanries]

All-

While winterizing my 1992 Maxum 1800SR I experienced an issue that never before has been a problem. After draining the block and manifold of water I remove the spark plugs, spray the cylinders with fogging oil and crank the engine over. Worked fine on the first fogging but when I repeated the cylinder fogging and then cranked the engine it continued to operate the starter. Had to disconnect the battery to get it to stop. Has this starter run-on happened to anybody else. Thinking it is an engine start switch problem but looking for any other possibilities. The starter and coil are only two years old so don't believe they are the problem. Help?
Note: Engine is the 3.0L Mercruiser.

Dean (deanries, Go Big or Go Home

[mmwjr]

Could a shorted ignition switch, slave soleniod, or starter soleniod. You'll need to isolate each to determine which is the fault.

[deanries]

Originally Posted by mmwjr

Could a shorted ignition switch, slave soleniod, or starter soleniod. You'll need to isolate each to determine which is the fault.

Thanks Mike, The starter solenoid and the starter were replaced two years ago and hopefully it is likely good. Pretty much thinking it is the starter switch but I will do a complete check of the system. Has anyone installed a starter push button switch (like the new autos) in their boat? Thinking of going that route, comments?

[mmwjr]

Originally Posted by deanries

Thanks Mike, The starter solenoid and the starter were replaced two years ago and hopefully it is likely good. Pretty much thinking it is the starter switch but I will do a complete check of the system. Has anyone installed a starter push button switch (like the new autos) in their boat? Thinking of going that route, comments?

I have done it but it should be easy enough to do. Do you plan to relocate the key or find a push button switch that uses a keyed fob?

Try disconnecting the low current wire on the slave soleniod to see if the starter stops, if so the key switch is bad. If still running disconnect the slve soleniod high current wire, if it stops the slave is bad else it between the starter and it soleniod.

[deanries]

Thanks again Mike for the details, I will use that in my troubleshooting efforts. Not sure on the switch, push button and FOB control. That's yet to be determined but will look at what's available and will work for my 1992 Maxum 1800SR. Went over 1300 hrs this past season so that the ignition switch is rather worn from use. Let you know how this all turns out. Appreciate all the comments/help.
Dean (deanries- Go Big or Go Home)

[deanries]

For those that operate with a Mercruiser 3.0L engine:

After inadvertently replacing the ignition switch (did not check to see if it was at fault, my bad) I still had the problem. Well I checked out the slave solenoid and it functioned as designed leaving me with the starter. Well when I removed the starter I found that something had ground metal off the starter housing. The only moving part is the flywheel (where the starter engages). I turned the engine over manually and only saw that the mounted weights were the closest to have been in contact but no indication of damage/worn, etc. Can someone tell me what is causing this, HELP! I put on the new starter and when i started the engine you could here hear something hitting the starter then in quit. Most likely what had happened three years ago when the starter was replaced by a local marine shop I use. Is this a vendor problem with then starter or is there something coming apart on the flywheel? Looking for some ideas even if I will have the pull the engine, OUCH!

[mmwjr]

This sounds different than your origional post where you stater that the starter kept running, now it sounds like you are talking about an interference issue.

Is the starter bolted on correctly? I have heard of mismatch between new starter housing and bolt lengths that allows the bolt to bottom out without the starter being held tight up to the engine. After some operating time this results in the bolts to break off.

When you pulled the last stater was there any signs that the flywheel was hitting any part of it?

[deanries]

Originally Posted by mmwjr

This sounds different than your origional post where you stater that the starter kept running, now it sounds like you are talking about an interference issue.

Is the starter bolted on correctly? I have heard of mismatch between new starter housing and bolt lengths that allows the bolt to bottom out without the starter being held tight up to the engine. After some operating time this results in the bolts to break off.

When you pulled the last stater was there any signs that the flywheel was hitting any part of it?

Mike -

First, the issue is the starter continues to operate, does not disengage when you play the ignition switch to run. The starter that was removed did show signs that something on the flywheel hit and gouged out metal on the starter housing. The removed starter was installed and tight, no gaps. For the new starter the same is true plus installed with the provided new bolts. When I turned the engine over by hand the only thing close was the weights on the flywheel itself. That's why I am concerned as to what & why on the riding condition.

[mmwjr]

Don't trust the bolts just because they are new and came with the starter I have heard so many times the wrongs bolts came with the starter. Before installing a starter insert the bolts to ensure only threads are exposed and not any of the non threaded portion.

Regarding the starter staying engaged did you verify voltage on the stater soleniod goes away once the key is released and it springs back to the run position?

Pre vortec and Vortec engines have different flywheels, do you have the correct starter for your engine?

[deanries]

Mike -
The bolts were just fine and fit as required. The slave solenoid was checked and did engage (switch to start) and then disengaged (switch to run). You could hear the solenoid moving as well. As far as the correct starter it was selected based on the engine serial number so one would think it is correct? Something on the flywheel grinds out the starter housing when first started, now the issue is like "what problem" as there is no riding condition now. That is why I am concerned but the boat is operating fine even with this concern!
Dean (Go Big or Go Home)

[mmwjr]

Since you are not hearing any grinding once running the only thing that makes sense is bad teeth on the flywheel against the starter gear.

[deanries]

Mike -
No, it is actually something on the flywheel that was making contact with the starter housing. I have not taken any photos but maybe that would help. It actually gouges/cuts on the housing until it clears itself. When I first started the engine with the new starter you could hear it contacting the housing until it removed the metal that it was contacting there. Seem to occur on every revolution of the engine and not a 100% interference, would not have been able to install the starter if that was the case.

[mmwjr]

Well the only thing I can think to do at this time is remove the starter and turn the engine by using a socket on the balancer bolt turning counter clockwise until you can see the interference mark on the flywheel. Then you'll have some idea of why it's hitting.

[deanries]

Mike -

No way to get on the balancer bolt due to the engine mount. I did turn the engine over using the water pump pulley with the plugs out. Did not see anything unusual indicating what was hitting the housing. Only thing that it could be is the balance weight, don't think it can move though? Very unusual.

Dean (Go Big or Go Home).

[mmwjr]

Originally Posted by deanries

Mike -

No way to get on the balancer bolt due to the engine mount. I did turn the engine over using the water pump pulley with the plugs out. Did not see anything unusual indicating what was hitting the housing. Only thing that it could be is the balance weight, don't think it can move though? Very unusual.

Dean (Go Big or Go Home).

Agree the weight is welded on.