Merc 470 Starter Amperage?

[big_chief]

What amperage should the starter test? Motor is 1981 Merc 470 (Grady White).

I brought the starter to the auto store and the reading was showing only 75 amps... Sometimes, the starter would not turn over, unless hit with a mallet... but nothing past 75-80 amps.

BACKGROUND:

Ran fine for about a year... then sat about 2-3 months. The boat is weak turning over. I tested battery(s), charged, etc... and they seem fine. Also had them bench tested at the auto store. 910 cranking amps on one... 625 cranking on the other.

Gave it afew cranks and it would barely get the motor turned over. Then it stopped trying to start completely. I hit the starter afew times with a mallet and it tried again to turn over... So I assume its the starter.

I pulled the starter out of the boat and gave it 12 volts... it makes a "clunking" sound when starting compared to a "wing-wing" sound that I am used to... Sometimes it wont even engage, unless you hit it.

Model: Arco 50143... Sells for $225.00 on the net... Anyone know where to get one cheaper?

Thanks,

 

[Bondo]

Re: Merc 470 Starter Amperage?

Sometimes, the starter would not turn over, unless hit with a mallet... but nothing past 75-80 amps.

Ayuh,... Electric motors don't take much amperage, til put under Load....
The Free-spinning Test is pretty much irrevelant...

The fact that it don't work, til ya Beat it,...
I'd say you probably need a New 1, or have that 1 Rebuilt...

 

[Don S]

Re: Merc 470 Starter Amperage?

If it has to be hit with a mallet to make it run, get it checked out and rebuilt at your local starter/alternator shop. Much cheaper than a new one.

 

[GLENN M]

Re: Merc 470 Starter Amperage?

when brushes are worn out,you can usally get it to start once or twice by hitting starter housing,after that your paddling only options rebuild or replace.

 

[stonyloam]

Re: Merc 470 Starter Amperage?

the starter would not turn over, unless hit with a mallet... but nothing past 75-80 amps.

Those 470 starters have a rather long armature shaft and oftentimes it will bend or break under load. The windings will then rub against the field coils and cause a slow turnover. Sounds like you need a rebuild, or go with a new permanent magnet gear reduction starter (part # 2-2591-DR-2) About 2/3 the size of the old one and probably no more costly than the rebuild (about $140). If you have the old style starter without the solenoid mounted on it, you can use the PMGR unit by using the engine mounted solenoid as a slave for the new starter. Good luck.