Starter requires jumping.4.3 1990 cobra. Troubeshooting? New starter even available?

[andrewbabich]

So I'm trying to get my buddies old 1990 4.3 cobra boat started and it requires some starter jumping to crank the engine otherwise it just gives us the 'click' when we turn the key.

I can get the starter to engage the pinion gear into the engine with the key, but this will not spin the starter. It just sits engaged.

At this point I need to 'jump' electricity from the red starter terminal to the big screw post that is grounded on the starter with needle nose pliars. At this point the starter cranks the flywheel and the engine cranks.

Sometimes when I jump these two starter terminals without turning the key it will engage the pinion gear into the flywheel and crank it, but normally it just spins the starter without engaging it. For this reason we always are turning the key and then jumping the starter terminals.

I have unscrewed the bolts and cleaned the contacts with a wire brush. (Big red wire from the starter, and little black wire which I'm guessing is the ignition wire???)

Why is this? Could it be a signaling issue from the ingintion key, is it a starter solidnoid problem.

How do I troubleshoot it.

We have the battery hooked up to a running diesel truck so we have plenty of amps.

If in fact the starter needs replacement are they hard to/ impossible to find replacement parts since its an omc sterndrive that is now out of business?

 

[erwinner]

Re: Starter requires jumping.4.3 1990 cobra. Troubeshooting? New starter even availa

Sounds like a solenoid problem. Easiest way to check if you can get to it without lifting the engine would be to pop it off and take it to AutoZone etc. or a starter/alternator shop and have them check it. OMC made parts are hard to find now that they're defunct, but lots of engine parts were sourced from automotive makers, so I'm pretty sure you'll still be able to find one easily.

 

[Don S]

Re: Starter requires jumping.4.3 1990 cobra. Troubeshooting? New starter even availa

Could also be a slave solenoid. Read this troubleshooting thread.

http://forums.iboats.com/showthread.php?t=167035

 

[Big_Eddy]

Re: Starter requires jumping.4.3 1990 cobra. Troubeshooting? New starter even availa

95% certain the solenoid is not making electrical contact when activated. Take the starter off the engine (note which wires go where), remove the solenoid from the starter, and remove the plunger. Considering the pinion as the FRONT of the starter, there will be a second small plunger in the BACK of the solenoid that is activated by the main plunger in the front. This BACK plunger has a copper pad on the back of it that makes contact with 2 copper pads in the solenoid housing to connect battery power from the solenoid terminal to the motor terminal.

Use some fine emery paper to shine up the copper on the plunger and both terminals, then reassemble it.

The fact that the pinion advances tells me the solenoid is activating with the key switch, and the fact that jumping with the pliers makes the starter turn tells me that the motor is good. Fix the electrical connection in the solenoid and you should be good.

Bench test before you assemble it back onto the motor just to be certain.

Any starter / alternator shop can do the work for you if you are not up to doing it yourself. Watch for the wires connected to the solenoid coil - break one and you're done.

 

[andrewbabich]

Re: Starter requires jumping.4.3 1990 cobra. Troubeshooting? New starter even availa

Alright thats GREAT info guys. Thanks for the troubleshooting diagram and instructions Don and Big Eddy. Just to clarrify things...

The click the troubleshooting guide refers to.. Thats the starter engaging into the flywheel right? Cause I think thats what mine does.

Then what I'm doing is turning the key then jumping across terminal A to C on my starter solinoid and then it cranks like crazy.

The trouble shooting guide makes it sound like it could in fact be the slave solinoid. I have yet to track that down. I will look for it. Any ideas where it's located on the boat.

How do you start looking for parts for OMC sterndrive boats. What kind of shop would carry slave solinoids or starters for a 1990 conquest should I need one. I'm confident i'll get the starting system fixed.

Now I need to focus on getting new fuel into it to get it to fire up and identifying the leaking water from under the starter when we crank the engine...

 

[andrewbabich]

Re: Starter requires jumping.4.3 1990 cobra. Troubeshooting? New starter even availa

The trouble shooting guide says to jump from terminal a and b on the starter solinoid if you need to jump it in a pinch. I have yet to try that and will do it, but what I also have to ask is

"By jumping terminal A (the hot wire from the battery) straight to terminal C (the ground from the solinoid to the starter) am I doing bad things to the starter or voltage regulators or something.

Could I have already done some damage?

 

[bruceb58]

Re: Starter requires jumping.4.3 1990 cobra. Troubeshooting? New starter even availa

The trouble shooting guide says to jump from terminal a and b on the starter solinoid if you need to jump it in a pinch. I have yet to try that and will do it, but what I also have to ask is

"By jumping terminal A (the hot wire from the battery) straight to terminal C (the ground from the solinoid to the starter) am I doing bad things to the starter or voltage regulators or something.

Could I have already done some damage?

Terminal C is not a ground.

 

[andrewbabich]

Re: Starter requires jumping.4.3 1990 cobra. Troubeshooting? New starter even availa

oh I gotcha. So terminal c isn't a ground, but it does send the electricity into the starter right? Thats what I'm doing when i bridge terminal A and C right? Sending electricty from the hot terminal straight into the starter right?

Is this a bad thing to do?

 

[Bondo]

Re: Starter requires jumping.4.3 1990 cobra. Troubeshooting? New starter even availa

oh I gotcha. So terminal c isn't a ground, but it does send the electricity into the starter right? Thats what I'm doing when i bridge terminal A and C right? Sending electricty from the hot terminal straight into the starter right?

Is this a bad thing to do?

Ayuh,... Doin' that, yer just by-passin' the starter's solenoid with full power...
But, by by-passin' it that way, the solenoid ain't gonna push the bendix out to engage the flywheel...

 

[Lou C]

Re: Starter requires jumping.4.3 1990 cobra. Troubeshooting? New starter even availa

There are several aftermarket companies that make good starters for OMCs, and they are the same or very similar to those used on Merc and Volvo versions of the same engine. I have a Sierra starter on my engine now and I had an MES one before that. Both work fine and can be bought from marine retailers for about 165-170. Or you could have yours tested and fix what's needed. The solenoid is only about 35 or so and very easy to replace.

 

[Dakota47]

http://www.dbelectrical.com/p-2280-marine-starter-v6-v8-gm-2-long-bolts-mercruiser-omc-sdr0031.aspx

 

[andrewbabich]

Re: Starter requires jumping.4.3 1990 cobra. Troubeshooting? New starter even availa

It runs!!! And we destroyed the gear on the starter. We purged the old gas between the filter and the carb and ran new gas from a pump siphon right into the fuel filter. With the choke on she roared to life!!

We still were jumping the starter by dumping power directly from terminal a to c with a wrench. Not sure if we hit it again while the engine was running or what but after two or three rounds of about 5 seconds running on choke it would die. The starter was being manually triggered and we must of grinded it into the flywheel or something cause soon even the manual trigger method of terminal a to c stopped making the starter do anything

So we were still happy to have an engine that ran and we pulled the starter. That starter gear was pretty well destroyed when we removed it.

I'll follow up with a picture when I can.

Next up we'll test the starter at autozone and probably replace or rebuild it.

The whole time the engine was pouring out water from some hose behind the block. There were wire clamps back there, maybe one was loose. I couldn't tell. The block plugs were all in place.

 

[andrewbabich]

Re: Starter requires jumping.4.3 1990 cobra. Troubeshooting? New starter even availa

I found new marine starters on ebay for $60. I gotta go for those. Anybody have any experience with these or a reason not to buy them? 12 month warranty. I don't want to wait for it to get here as it won't even ship till monday, but for that kind of savings i have to.

 

[Lou C]

Re: Starter requires jumping.4.3 1990 cobra. Troubeshooting? New starter even availa

I like to buy stuff like that from local retailers so if there is a problem it's easy to return. I paid about 165 for the Sierra one on it now.....

 

[sethjon]

Re: Starter requires jumping.4.3 1990 cobra. Troubeshooting? New starter even availa

The only part hard to find is the manifold and even that has new kit replacement.