4.3L Mercruiser - weak start - not battery..

[Scag]

Hello! Thank you for taking a look a this post, I appreciate your time!

I have a year 2000 4.3L 190hp Mercruiser in my Ebbtide Campione. I've noticed that when I turn the key, there is a slight hesitation before the starter begins to crank. It seems very weak until the boat turns over Here are the facts:

• Tested the battery, its holding full charge, appears to be in good shape
• The hesitation which is silent lasts about .5 seconds, followed by a very strained crank - yet the motor turns over fine
• This happens when the boat is cold or hot, maybe slightly worse when cold

The problem is not that the starter runs for a while and it takes a while for the boat to turn over. Its turning over fine, but it seems the crank is getting weaker and weaker, as if the battery was dying....but the battery checks out fine.

How should I go about diagnosing the problem. I know very little about the starting mechanism and all the parts related to it. I appreciate any help in advance!

 

[timfives]

Re: 4.3L Mercruiser - weak start - not battery..

Hey,

You should do a load test on the battery, Charge is one thing, but amperage is what you need. A load test may show that it is indeed the battery.

The other item it could be is high resistance in the started solenoid. My bet though is the battery. Good luck

T

Hello! Thank you for taking a look a this post, I appreciate your time!

I have a year 2000 4.3L 190hp Mercruiser in my Ebbtide Campione. I've noticed that when I turn the key, there is a slight hesitation before the starter begins to crank. It seems very weak until the boat turns over Here are the facts:

• Tested the battery, its holding full charge, appears to be in good shape
• The hesitation which is silent lasts about .5 seconds, followed by a very strained crank - yet the motor turns over fine
• This happens when the boat is cold or hot, maybe slightly worse when cold

The problem is not that the starter runs for a while and it takes a while for the boat to turn over. Its turning over fine, but it seems the crank is getting weaker and weaker, as if the battery was dying....but the battery checks out fine.

How should I go about diagnosing the problem. I know very little about the starting mechanism and all the parts related to it. I appreciate any help in advance!

 

[Scag]

Re: 4.3L Mercruiser - weak start - not battery..

I'll give that a try. My neighbor has a battery testing that we used to charge and test it. I will confirm with im that this also checked the load.

 

[Don S]

Re: 4.3L Mercruiser - weak start - not battery..

Make sure all your battery connections are clean and tight. Wing nuts with your thumb and finger is NOT tight.

 

[ussoldier_1984]

Re: 4.3L Mercruiser - weak start - not battery..

It could be the slave starter solenoid goin out if its not your battery.

 

[HT32BSX115]

Re: 4.3L Mercruiser - weak start - not battery..

Howdy,


A good way to test for "good' connections is to connect a DVM (digital volt meter) to the battery (NEG) and starter (POS).

crank the engine and note the cranking voltage.

move the POS lead of the DVM to the solenoid, and to each connection until you ge to the battery.

You should get no difference(or very little ) in voltage at each connection (DURING CRANKING) If the voltage is a LOT lower at the starter than at the battery (ONLY during cranking) you may have a poor connection somewhere between the starter or the battery OR a poor connection between the battery NEG and ground (block etc) A burned (internally) solenoid can also cause the same problem......

Please note that you must be cranking the engine to make the voltage measurements....... The starter can draw 100A or more current.... no cranking=no current and means no voltage drop across poor/corroded connections......

Many cranking problems in boats are due to corroded/loose connections in the electrical power cables.connections

 

[Scag]

Re: 4.3L Mercruiser - weak start - not battery..

:update:

Ok, had the battery further tested with a mech at the shop. CCA are in check (550 as the battery is rated) and holds a charge ....

Now I am looking into the connections....i'm going to try to clean the connections, then start with what HT32BSX115 has recommended. Just gotta get my hands on a DVM. Hoping to do this in the next day or two so I can update you guys. I really appreciate the help everyone!

 

[EMC 1810SS]

Re: 4.3L Mercruiser - weak start - not battery..

My starter was doing the exact same thing this summer. I chased all of the connections, terminals and even a new battery, then in August the starter let the smoke out. I replaced it with a new Mercruiser Starter. I had forgotten how fast my 4.3 started when new. extreemly noticable difference. At over 200 bucks just for the part and no good way to remove and replace it, it is definetly worth your while to check ALL connections and cables FIRST.

 

[Scag]

Re: 4.3L Mercruiser - weak start - not battery..

Yeah, I hear ya. I don't want to jump to conclusions, but if it ends up being the starter, is there a good resource or thread that you followed that helped you with the replacement/install?

 

[EMC 1810SS]

Re: 4.3L Mercruiser - weak start - not battery..

Nope, I just put a few folded towels in the bilge, and stood on my head and did it. Its pretty easy to get to the wires off. Take a photo of how the wires are attached. My main power wire only has one oreintation that keeps it from rubbing on anything else. I never would have gotten it right without a photo for reference, then its just two long bolts at the bottom of the starter. I had to remove bothe from the block and pull the starter and bolts out all as one becuase I dont have enough room to slide the bolt hout without hitting the bottom. Then its just putting it back in the way it came out. Unless you have a hard head, dont forget dome padding!

 

[mnypitboat]

Re: 4.3L Mercruiser - weak start - not battery..

I had the same problem on my 5.7 Mercruiser. I had replaced the starter, both batteries, the solenoid and all cabling. So at the beginning of the season when I had the same problem again, I was not happy. I cleaned the connections and all, but still had a problem. I could put the switch to both batteries and it seemed fine, but with only one battery it barely turned over. I ended up replacing the solenoid again, but this time I put a heavy duty solenoid from an early 80s Ford in there. No more problems. I had replaced that solenoid with genuine Mercruiser parts, and with the ones at West Marine. 1 to 2 per season, then when I put this one on there it really brought it alive. It starts better than it has since I bought it.

Just something to think about after you clean up and fix all the connections.

 

[Scag]

Re: 4.3L Mercruiser - weak start - not battery..

A few more questions

1. Is the solenoid located on the actual starter? That is....if I get a new starter, will it come with a new solenoid as well?

2. My battery is rated at 550 cold cranking amps and the battery is checking out fine, producing those CCA's....I'm using the battery that was in the boat when I bought it and I dont remember having this problem until recently, but could this motor require a much more powerful battery?

3. What would the best place to buy a starter be? I haven't narrowed it down exactly to the starter, but until I can work on it further (time), I'd at least like to get an idea of how much this will set me back if I do need to buy a starter.

Thaks for the help.

 

[Bt Doctur]

Re: 4.3L Mercruiser - weak start - not battery..

Did you remove the neg. block connection and clean it? Try testing the battery cables , visually inspect for corrosion at the cable ends, a cable could be corroded internally too, unseen. Use a good set of battery jumpers to the starter and block, if it improves, your battery cables are bad . Can be tested with a meter by removing the cables at the battery, 1 lead to the starter and the other lead to the + connector "0" ohms, do the same with the neg cable, 1 lead to block ,other to neg cable end, "0" ohms