New Sierra Merc 5.7l Starter Not Engaging Flywheel

[thormx11]

I am having starter troubles on my boat. Engine is about a 2000 model 5.7l carb engine. Towards the end of the season last year the starter started to sound bad. It got to a point where if it cranked for more than a couple seconds the appendix would disengage from the flywheel and just spin. If you let off of the key and try again it would turn the engine over for a few seconds before disengaging again. It would always spin, just not turn the engine over.

I ordered a cheap marine starter and tried it and the appendix would not engage at all when testing it on the bench before installing. It would only spin but the appendix would not come out.

I sent it back and ordered a new Sierra starter and am having the same issue with it. I am only grounding the starter and adding power directly to the terminal going from the solenoid to the case of the starter. The starter spins just fine but the appendix wont come out. I also tried doing the same thing to my old original starter and it is doing the same thing as the two new ones.

Am I jumping the solenoid wrong or did I just get 2 bad starters in a row? I know it is possible but doesnt seem very likely.

 

[Scott Danforth]

i hope your appendix is not coming out

the bendix is the drive portion of the starter

however the M terminal (with the lead between the solenoid and the starter not where you want to put power. you should not touch that. that is the field wiring to the motor.

you should have a ground on the mounting lug and the battery hot going to the B terminal. then jumper the S-terminal to the B terminal

 

[Lou C]

for the starter to crank you need a ground (starter body connected to battery negative), and 12V at the larger B+ terminal on the solenoid and also at the S terminal on the solenoid...B+ is the large terminal for the positive battery cable, the S (for start) is small terminal which is connected to the yellow/red wire from the ignition switch Start terminal. For the ground and B+ you can use jumper cables and a remote starter switch can be used to jump between the B+ and the S terminal.
If it doesn't work this way then take it back.
If it does and won't crank in the boat, make sure that:
the engine block where the starter bolts is clean
the battery + cable is not internally corroded and you have battery volts measured at the cable, no voltage drop
you also have battery voltage at the yellow/red wire when someone turns the key to start
if not you need to replace the battery + cable and/or troubleshoot the starter wiring circuit.

 

[thormx11]

I should have mentioned the engine is out of the boat and on a stand. I will try it as Scott mentioned above and see what happens. I am waiting to get the starter issue figured out before i drop the engine back in the boat.

 

[Scott Danforth]

if you have the flywheel on the engine, simply bolt the starter to the motor, wire it properly and test.

BTW, your last starter probably simply needed a bit of TLC to be working top notch. a bendix and solenoid kit would have been under $35 from your local starter/alternator shop.

 

[Bt Doctur]

Also check the ring gear for missing/damaged teeth

 

[tank1949]

Also check the ring gear for missing/damaged teeth

My ring gear tore up because circuit breaker defective and starter was not getting proper voltage/amps. 30+ year old breakers have now all been replaced. Tore up starter's teeth too. Replaced starter!!!!! Lesson learned.... The hard way...

 

[poconojoe]

Sounds like a bad battery. Did you use the same battery to bench test both starters?
Could be bad connections too. Corroded connections can cause unneccessary resistance.
Take all connections apart one by one and clean them shiny clean, then tighten securely. Clean the posts, nuts, washers, and wire ends. Check all cables for corrosion. Sometimes they can corrode from the inside out. Look close near the connectors for green corrosion within the strands of wire. Make sure your wires are marine compliant (tinned). And absolutely check the condition of your battery. Try a different battery, if you can.
Sometimes a battery might appear to be good, but may have a bad cell.

 

[Lou C]

Sometimes you can charge a battery back to what appears fully charged but it will fail a load test; or will test as marginal. I’m using one of those electronic load testers now and while there is debate on whether these or the old style testers are better, when this one says replace the battery it has been in fact on the weak side for a while...