Mercruiser 5.7 EFI : starter motor clacking but not turning engine over.

pistole

Hi guys.

Need some help here. My newly acquired 330 has developed a starter issue with the Port Engine. Starboard engine starts fine. 

When I turn the key , I hear the starter try to engage (the loud clacking klak-klak-klak sound). But not enough to turn over the engine. 

On a car , you would probably say poor grounding , weak battery or something along those lines.

I searched here and there is mention of a starter solenoid , relay and poor battery connections. 

I spent some time today and cleaned all the batt connections but no joy. It still klaks , and if I am lucky , she starts.

I really don't wanna rely on my luck (what little there is anyhow) and a starboard engine to get home .

Thanks in advance for your help here. I am a reasonable motorcar and moto cycle mechanically inclined person but these inboard marine motors are new to me 

aero3113

Were you able to check the connections on the starter side? When the starboard engine is running do you have full voltage at all of the batteries? It sounds like you don't have enough juice to start the port engine.

zaverin1

My guess on a efi system it’s the starter taking a crap.
Older Mercs has a Aux solenoid ontop
of the engine.

GMSLITHO

I agree just get a new starter and be done 

Black_Diamond

Start with the circuit breaker on top of the engine. Has a red button on it, right behind the throttlebody. $20 part. They do die. Same one that is on your outdrive pumps too.  

zaverin1

If that went there would be no click 

rasbury

Get the manual out and there are trouble shooting test to determine if it has gone bad. I don't think these motors are different than car motors- they are car motors. So, the same issues and tests that apply to your car are the same here. I don't recall exactly how I tested it, not sure I really under stood what I was even doing. I can follow directions, tests said it was bad internally, pulled the starter and had it rebuilt. No starter issues since.

zaverin1

Itake a volt meter and check for voltage at the starter.
if power is getting to the starter but you get a click then it’s the starter. Obviously check voltage at the starter at the same time
to make sure it’s not to low.

zaverin1

FYI if low voltage at starter start looking at batteries first ans finish by tracing all wires back to starter.
my buddy has a 300 ray twin 350 efi
his starting issue was a hairline crack in the fuse that would cut in and out 

pistole

thanks for the comments. Really appreciated.

I brought a fully charged car battery and thick jumper cables to the boat yesterday and boosted each battery whilst attempting to start the port engine (since I couldn't tell which was the battery meant for the port engine ... ).

No joy , the fuel pump primes when ignition is turned on but when my son tries to start , we hear the klak-klak-klack from the starter solenoid. So basically I can say that battery power is not the issue.

the former owner (who is still at the same marina) said that it has done that before and his solution was to manually turn the motor a bit with a wrench to the raw-water pump pulley in order to allow the starter to engage. I thought long about this and couldn't imagine that it would have any effect unless the starter's pinion is somehow unable to engage with the flywheel.

am leaning towards buying a new starter , but crawling around the engine bay yesterday I couldn't even locate it .. much less start thinking about how to remove/replace one in the boat. Thank the gods that the 330's engine bay is still reasonably large.

as for checking the large red button breaker on the top of the engine , yes , my engines do have that breaker. What is it supposed to do (or not do) ? I am getting the solenoid klacking on the starter and am assuming that therefore power is reaching the starter.

looking forward to some advice / help here. thanks in advance again.

randy56

It's so much fun changing those starter's, knuckle buster, feeling for bolts, don't forget to unhook the battrie. You will learn to speak a new language . The other alternative is to call the $100 per hour mechanic.   

pistole

I have alot of respect for people who earn their money with their hands , so I don't begrudge someone charging what his time is worth in a fair way.

Am just trying to learn as I go along with these inboards. 

zaverin1

That’s the main breaker For each engine, 

probably a bad bendix I doubt it’s a flywheel issue 

pistole

zaverin1

Yikes

zaverin1

Now that was a fire hazard 

Dream_Inn

Oh wow!  That does not look good. 

zaverin1

Starter time 

rasbury

what the heck is that? And, as long as you don't get dizzy standing on your head, the starter is a piece of cake!

aero3113

Nice cheap fix! Just make sure it's the correct amperage.
NEW 90A FUSE ASSEMBLY FITS MERCRUISER 3.0L 4.3L 5.0L 5.7L 6.2L 7.4L ENGINES 88-79023A91 8879023A91 https://www.amazon.com/dp/B017OBIV58/ref=cm_sw_r_cp_tai_pW1GAbRC0BJR7

rasbury

is that the relay on top of the motor? What ever it is, Yikes!

aero3113

No, the fuse that is bolted to the starter positive post.

aero3113

#8 in this parts diagram.

http://www.mercruiserparts.com/bam/subassembly/31754/15322/10

zaverin1

It’s technically not a fuse. It’s a junction but there has to be more to the story for it to get burnt like that 

aero3113

I read if your battery was hooked up incorrectly this can happen.

aero3113

zaverin1 said:

It’s technically not a fuse. It’s a junction but there has to be more to the story for it to get burnt like that 

A junction with a fuesable link, I would say it's a fuse.

randy56

Was it a loose connection the culprit? 

pistole

yes , loose connection and poor cable condition. It then caused that 90A fuse connection to build up heat resulting in resistance and a poor connection. Power was still flowing to the starter solenoid but not enough to close the connection and spin the starter motor.

something for boat owners to look out for as their systems age.

Thanks guys.

rasbury

Noted!

pistole

am just starting to appreciate that the main problem with servicing inboards is difficulty with physical access.

zaverin1

Inboards?