Starter on 12V71TI Problems

[MicroKap]

The starter on my starboard engine didn't seem to "disengage" while starting the engine. The engine would get up to around 450 RPMs and then stop when the start button was let go.

I was told that this is symptomatic of a starter needing a rebuild. I'm heading down there in about 1 hour and wanted to know if anyone had any helpful hints/tips on how hard this is going to be.

The engines are 12V71TIs with 650 HP. Starter is on inboard side (really easy to get to).

If anyone has "steps" to do this in would be very helpful.

Thanks in advance.

 

[Boatsb]

Step 1) Mark all wires clearly and note where the go
Step 2) Remove the battery terminals
Step 3) Remove the battery terminals
Step 4) make sure no other wires at the starter could be energized. Remove the keys and tape over them.
Step5) get a volt meter or test light and check for voltage at the wires on the starter and solenoid
Step 6) Remove the wires at the starter and solenoid now.
Step 7) remove the starter bolts and get a forklift for lifting the starter.
Step 8) bring it to a good re builder. Too much work to cut corners.

Installation is the opposite.

Make sure you remember the grounds too. they are just as important and just as dangerous if they get shorted out and I know the 32 volt systems will melt things if there is a short.

I am not trying to be an a-hole but it just works that way. Really there are more times than I care to count that someone pulled a starter with wires connected and fried something or could have been hurt.

 

[yachtsmanbill]

Turn off the battery ISO switch, and stab the motor to make sure its out of service ! 32 JOLTS is in the arc welding range ! Some accessories are tapped off the aux stud on the motor so you may have to temporarily hook some wires together and tape them up. The units almost 100# (75??) so be prepared to bustanut LOL. Putting the new one in, ( or taking the old one out for that matter) you may want to invest in a 10" 5/8 stud to ease it in and out.
TJMHO !!
Make sure that you get the correct rotation starter. The 12s turn inboard (with allisons) That would make that a standard rotation unit. The bolts are 12 point heads, so youll need a 12 point socket, and they are A$$hole tite ! ws

 

[Pascal]

had to pull one of mine last year (8V71) much easier than i thought. of course the patented Detroit anti corrosion system means bolts can't rust and seize it's a little heavy, but not too bad. not sure if the 12s are much bigger than the 8s...

had it rebuilt by a local shop. it had failed to retract after startup and self destrcted internally.


"The engine would get up to around 450 RPMs and then stop when the start button was let go."

not sure what you mean by that. if it doens't disengage, like mine, the engine will spin the starter motor real fast causing it to self destruct. is shoudln't stop the engine from running. the rebuilder told me that sometimes you can hear the noise when the starter doesn't disengage.

 

[MicroKap]

Will turning off the battery switches do the same thing as taking off the terminal connectors on the batteries? If I then take my multimeter and tap it on the starter, I should see no power?

I like the idea about the idea about the 10" 5/8" stud, but where do I find one?

 

[SKYCHENEY]

Pulling the wires at the battery posts is just fine. I'd still test the other end just to be sure.

 

[yachtsmanbill]

Simplex stud or allthread can be bought at Ace or HomoDepot etc. I am guessing at 5/8... may be 1/2 but I seem to remember its' stout. Pull the easy bolt for a size, or just buy two studs at a buck a piece.
The switches are the easy way without disturbing the batteries, plus the bilge pumps are probably wired HOT to the HOT side of the switch. Make sure the pumps run before you leave the boat !! It is however a good time to inspect the battery clamps for corrosion etc.
Make sure you stab the starter though, and if you hit the parallel switch that side becomes hot also. Dont let any kids near the helm when your doing this !!
ws

 

[Boatsb]

If the battery post has no wire on it nothing can happen. Switches get turned on. keys get put back in. If you are leaving the boat a few days and someone may go aboard they could turn on the switch and cause a short.

 

[shvldis]

Are you shure you have a starter problem? Sounds like the engine isn't starting. A starter that dosen't disengage will over-rev and come apart, It can't possibly "Stop" a running motor.

 

[MicroKap]

I took the starter off last night with some assistance. The new line is, "Good tools aren't cheap and cheap tools aren't good". We were done in a matter of 15 minutes. The teeth on the starter were partially worn away and there was a lot of play in all the moving parts that were visible. The wheel on the engine looked fine. I dropped the starter off this morning to get rebuilt and they said that everything that I described would have happened with the starter looking like it did.

Just for reference, the two "visible" bolt heads were 6 sided 15/16" heads and the "top" bolt was the 9/16" 12-sided. A good extension for the socket really came in handy for the "invisible" bolt.

I'll let you know in a couple of days the results of this exercise. Thank you for your help.

 

[JLR]

Larry - although not my thing, I have replaced the bendix before on my starters. Are you sure it is not this? If it is, I can provide a source for some inexpensive bendix replacement parts, if needed.

 

[yachtsmanbill]

Larry... when you re-install, make sure the 6 point bolts are grade 8, thats six lines or more. You should probably fish around the bilge right there with a magnet for the old 12 point bolts! They are super duty, and stay in the socket for the install ! ws

 

[Pascal]

"The new line is, "Good tools aren't cheap and cheap tools aren't good"

that is so true... never rely on those crappy xxx sets made in china... i always have a full set of quality metric/standards sockets and wrenches on the boat and in the car. it can make the difference between driving home or being towed !

those 12 points bolts are great, no risk of damaging them

 

[Trojan]

Do you buy those by the pound? Is that another example of black gold? LOL Looks like you have the problem well in hand. Maybe you should be looking at the other side also before you go to far. They both should have about the same amount starting and use time. Just a thought.

BILL

 

[MicroKap]

The shop refurbed the starter yesterday. I think the only thing original is the housing. They said that the thrust washer was worn and created a lot of play in the other moving parts. The teeth on the Bendix gear were a mess. They replaced the windings, the bushings and all of the other parts for under a 1/2 boat buck. The shop said that everything looked pretty original. Not bad for a 1980 with over 3,000 hours on the engine. (The port engine has about 1,500 hours, and no problems starting.) Reinstalled last night and the engine started right up.

Just a note, my stop solenoid needed a slight adjustment which would explain why the engine would stop.

Last night went very smoothly. Fifteen minutes and we were back in business.