500 efi starter issue
 

We had a starter go bad on the starboard engine. I replaced it with a new Mercury starter, not a rebuilt one. Now when I turn the key it will turn the engine over once then the starter will spin free, let off of the key it does the same thing. I checked with the dealer I bought if from and they confirmed I have the correct starter. Does anyone have any suggestions as to what could be causing this to happen? I guess I'm going to have to pull it off again.

I'd say weak battery, or bad new starter.

I thought about a weak battery also, but the onboard charger says it is fully charged. I will put the volt meter on it tonight.

Keep in mind, that if you have a bad battery, it could still hover around the 12 volt mark, but with a load, drop fast. I'd have someone try to crank the motor over while you have a meter on the battery. I'd check to make sure your cables are on tight on the starter as well, may have a voltage drop there.

That seemed to fix the problem. Two new batteries and it started first time without even struggling.

I have not posted on this thread in sometime, but I'm still having starter problems. I replaced the new starter with my old one that was rebuilt just to make sure it was not the new starter I bought. The same problem that I had to begin with it will turn over a couple times then free spin, like it is kiking out. I let off the switch and try it again and it will fianlly fire. It has always started just takes a couple times. One thing I would mention is that on the same engine I'm having some gremlins, the tach is sort of jumping around. This will come and go though, sometimes it will be fine then next time you look at it, it will be jumping up and down. Any suggestions would be great.

Oh I will mention that I have swapped the tachs to rule out that. Still does it on the same tach once I changed them so it isn't the tach.

did you check to make sure you are not getting water in the
motor?? pull the plugs and see if it spins free.
cmi exhaust(if that is what you have) is good for cracks

When having any kind of starter probloms especially on a boat you have got to make sure battery voltage is sufficent and
both neg and pos cable integrity is intact. Battery must be
at least 12v and capable of a current loads of at least 400
amps during intial starter rotation. The cable connections must be appropriate and dont be fooled by what looks like a
a solid crimp. Some times if you lightly pull on the cable they
will slide out of what looked like a good crimp connection
at the terminal end. Never underestimate the importance of
ground connections as well as B+. I have seen many a tech
replace a starter only to find out that the core problom was
a connection. And never by the cheap, knock-off, pacific rim
built starters. YOU GET WHAT YOU PAY FOR

check the starter bolts to make sure they are not bottoming out on the shoulder of the bolt and not let the starter tighten up. you might also need to shim the starter, the merc number for a starter shim is 15-8172721. with the starter drive kicked out messing with the teeth on the flywheel you should have about .030" clearance

I think you might have something here. Now that you mention it that could very well be it. If the boat sets all week without being fired it will do it. But if you start it the next day it will not do it. It could have a small hole and it takes it two or three days to get the water in the cylinder. I will let it set the rest of the week and pull the plugs to see if any of them have water in them.

after you run it drain the water from the bottom of the CMI's , let it sit for a few days and if it still acts up then its not water, but if it starts fine you might have a leaking header, I hope not they are big bucks. I rigged up an automotive radiator pressure tester to pressure test my exhaust,

I think you can send them back to CMI and they can repair them. If it's one of the welds at the flanges I will repair that myself. Nothing a little TIG welding want take care of. I really don't want to repair a header, but on the other hand I would like to find out what the problem is.

I Had The Same Problem And Thought It Was The Starter But Was The Header Leaking Filling Up #6.

Good Luck

Was yours leaking at the flange or somewhere else. I was trying to figure out it the headers are mandrel bent as one piece inside or if it has welded splices in it.

WHEN YOU TAKE THE HEADER OFF AND LOOK WERE IT BOLTS TO THE HEAD THATS WERE MINE LEAKED THATS WHY IT ONLY WENT IN ONE HOLE...

I hope that's where mine is leaking because I can weld that up.

Well it's been two years now and still have not found the problem. It's not the headers leaking, I've replaced the battery cables, I replaced the starter. Now when I turn the key I get a single click, then nothing. Turn it again and and the same thing, sometimes it take three or four turns before it will turn over. Yesterday I shut the boat off two times and it did it both times. Friday I started the boat for the first time of the season and it did not do it at all.

This may not be the problem, but did you check the flywheel for missing teeth? Does it free spinn when you hit the key or is it just a click?

Try swapping the slave solonoid with the other eng. or just replace it.

Flywheel is in good shape. Thanks anyway.

That was my next move. I will probably replace the starter also.

Check to make you have the right shim.there are too styles part # 15-817272 or a special shim # 15-8172721. Also when you have the starter off take A mirror and look at the engine block holes to the starter bolts and look for cracks in that area. Hear is a long shot but I see this a lot. On the engine look for the main wire harness that has a black rubber round plug it gose up to the helm for the gauges. Make shur it is pluged in all the way with a hose clamp when done.Try moveing it round with engine off and on also to see what happens.Watch the gauges, then try starting it up a few times to see if that is your problem first. good luck.

Do you have a battery switch? If so, try by passing it or switch it with the other side. The contacts inside the switch can cause problems and change after they warm up.