Fast crank then slow crank?

[FishFind]

I read a old post and it was close to the problem that I have. I checked that battery and it is reading 12.5-12.6v at the relay before the starter. The voltage on the other side of the starter relay when the key is in the crank position is reading 6-8v. I dissconnected the cable from the starter and tested it there it read 12.5v for some reason the volts drop when it is trying to start the engine and the engine turns very slow. I took out the plugs and the engine turs over with no problem at all. when the plugs are in the same old bogging down. Every now and then if I wait a few it will turn over fast like expected but then I attempt 10 seconds after and it is back to a slow turn. Any ideas??

 

[robert graham]

Re: Fast crank then slow crank?

Remove, inspect, clean and tighten all battery/cable/starter/relay connections. The bad/weak connection may get hot to the touch after cranking on it. The connections can look good from the outside but have corrosion deposits where the metals touch. I use a 3M Scotchbrite pad or a wire brush to clean them until shiny. The battery cables can get moisture/corrosion inside them and reduce their current carrying abilities, and need replacing. Good Luck!

 

[99yam40]

Re: Fast crank then slow crank?

Check voltage on the battery terminals themselves,not the cable connections as you are cranking.
If it is dropping too much then your battery needs to be pulled and load tested and probable replaced.

If it is not dropping there then work your way down the cables checking for the voltage drop to pin point the bad connection.

 

[FishFind]

Re: Fast crank then slow crank?

ok I took a look the volt is 12.5 at the batt and at the cable before the cable. I took off the starter and took it apart looks ok but I did notice that the 4 carbon or graphite pads that touch it are warn down and for the most part dont make any contact anymore. can this be my problem

 

[robert graham]

Re: Fast crank then slow crank?

If you're talking about the starter brushes being warn down and not making contact, then yes, that could definitely be your problem. Although I've never heard of warn out motor brushes on a modern outboard, I'm confident it can happen. Good Luck!

 

[FishFind]

Re: Fast crank then slow crank?

Problem fixed! I noticed a small puff of smoke on one of the starts and I found out that the ground wire that comes from the starter was broken inside of the rubber case. I could not see it before and it had enough ground for the volt meter to read but when it was under load it could not ground all 12v and made it so it was only grounding 4-6v, changed the wire and all is perfect.

 

[99yam40]

Re: Fast crank then slow crank?

Good to hear you found your problem.
That is the reason you need to do the voltage drop test under a load such as trying to start. Bad connections do not show up unless you have a load on it