Mercury 85hp O/B hard to start.

[Mezadami]

Hi again,
Like most of you, I'm having trouble starting my motor. I've everything that is mentioned but what seems to happen is it stops cranking. It turns over a few times, stops followed by a buzzing noise. Sometimes out of the blue, it will turn over 8-10 times but stop again with this buzzing. Anyone know what this could be?

Tks again.

 

[Mezadami]

Re: Mercury 85hp O/B hard to start.

Actually, I should mention that the buzzing or humming is coming from the cranking motor. I just bought this boat a few weeks ago, got it started once out of the water with motor flush muffs attached to the lower unit. I don't know if it was coincidence or not but I had cleaned the gas filter moments before...

Tks

 

[Silvertip]

Re: Mercury 85hp O/B hard to start.

Most of us don't have trouble starting our engines. The problem with your engine would likely be 1) weak battery, 2) corroded battery cables, 3) loose battery cable connections, 4) bad starter solenoid, 5) bad brushes in the starter motor. That said, start with the simple stuff. Make sure the battery is good -- that means either substituting a known good battery or have the old one load tested. If the battery is good, juse jumper cables to jump from the battery directly to the starter. This eliminates all of the electrics except the starter itself. If the starter spins when jumped directly, the problem is with the cables or solenoid. If the starter does not spin when directly jumped, its bad.

 

[Plainsman]

Re: Mercury 85hp O/B hard to start.

Weak battery? Have you cleaned all connectiond on the battery? Is the noise coming from the starter?

 

[Mezadami]

Re: Mercury 85hp O/B hard to start.

The battery is new. I've checked and replaced the connections to the battery when I bought the boat. The problem is intermittent. One minute it will continue to turn over, the next time I try starting the motor, it turns over 2-3 and then stops followed by that humming/buzzing from the starter. I did get to start the motor today by the suggestions I've read which were given to others about cold starts. When I started it the first time, I didn't have a problem afterwards but the intermittent problem mentioned above is still a concern. If anyone else can help that would be great. When I have time I will check the the solenoid and brushes on the starter.

Thanks

 

[Mezadami]

Re: Mercury 85hp O/B hard to start.

Well after closer inspection and also troubleshooting at two heads instead of alone. The humming from the starter is actually the gear dropping back down and continuously spinning. Sometimes it stays up cranking the motor but most often it drops not making contact with the motor. Has anyone had this problem before or would know what I can do to fix it?

Thanks,
Mike

 

[ricksrster]

Re: Mercury 85hp O/B hard to start.

The drive gear could be worn causing it to loose its bite and slip back down.

 

[tashasdaddy]

Re: Mercury 85hp O/B hard to start.

usually the gears don't disengage unless the engine turn faster than the starter, as in trying to fire. even thou it's a new battery get it load tested, new things are some times bad. also make sure it is fully charged, if you been cranking on it, and not recharging, my charge has a starting mode, that boost the charge out put to 50 amps. which helps me in certain cases. check you cables, they have a tendency to get nicked, and corrode from the inside-out. i chased a problem for about 2 weeks until i found a small swelling in the battery cable, it only had about 3 strands making the connection.

 

[Mezadami]

Re: Mercury 85hp O/B hard to start.

Thanks tashasdaddy, I'll have to take a closer look at that.

And thanks to all your replies, keep them coming. I'm new at this but eager to learn.

Mike

 

[jddenham]

Re: Mercury 85hp O/B hard to start.

When I first got my boat the starter would barely turn, not fast enough to raise the gear up and engage the flywheel.

I took the starter apart and it was full of water! The old owner had left the cover off during rain.

Cleaned and dried it out good and it works fine now.