Yanmar starting question - again

[Blitz]

I have the problem in which the engine will start no problem the first time of the day, then it warms up, I go sailing and it always takes both battery banks to start the engine.

I did some tests - the first time on start the voltage was good - above 12.8 volts at the solenoid. After warming the engine and simulating a sail it was struggling to get to 9 volts and not strong enough to kick over the motor. (the batteries were showing a full charge.)

Having read the threads previously, I went ahead and installed the recommended relay at the solenoid to increase the voltage at the solenoid after the engine was warmed up. I didn't really notice a change yesterday afternoon after a sail. It still struggled and I will be doing tests shortly to confirm voltage. but it doesn't make sense why it doesn't work.

Have you had similar experiences? I guess I'm going to clean all the connections one more time to be sure. Thinking just change the harness???, or is it the solenoid fouling with carbon that needs to be dismantled and cleaned - did anyone ever do this?

Thanks for any insight or ideas you may have. Off to boat

 

[Don S/V ILLusion]

Resistance and temperature are directly related. When was the last time you removed and thoroughly cleaned all the connections?

 

[Deadline2]

Good point by Don

Relay did the job for me instantly. A nuclear physicst helped me, and we now refer to it as The Gadget.

Since it works like a charm, the explanation for your continued frustration could well be encrusted or loose leads. Check behind the wall panel as well, as a safety measure.

 

[Paul J. Rusyniak]

Blitz...
When it doesn't start, does it do anything?
Any noise?
Paul

 

[Tim R.]

Are you at a slip? Maybe your batteries look fully charged in the morning because they just came off the charger. Are your batteries showing full charge after sailing? Have you reconnected all battery cables at the batteries? It is simple and quick to do and rule out. Use some dielectric grease to prevent corrosion.

 

[zeehag]

is your alternator functioning properly?? maybe the connections involving the alternator are in need of being addressed---???? is the bendix engaging?? do you hear a spinning noise or is it dead quiet????/ does it click??

otherwise--maybe a push start?? LOL.....sorry --i could bnpt resist that on e...LOL-- :dance:

 

[Warren Milberg]

Although your batteries may seem to be "fully charged," that is, they may read 12.8vdc on a DVM, that does not mean they can put out the needed cranking amps to start your engine. I would recommend having them load tested at either West Marine or most auto supply shops that can read cranking amps.

 

[Blitz]

I try to clean all batt and connections to the starter every spring including this spring. Think this is normal. Never much of any corrosion.

 

[Blitz]

Are you at a slip? Maybe your batteries look fully charged in the morning because they just came off the charger. Are your batteries showing full charge after sailing? Have you reconnected all battery cables at the batteries? It is simple and quick to do and rule out. Use some dielectric grease to prevent corrosion.

Batteries are at 12.8 or above. Cleaned a lot today but not much except a little where harness attached to a ground which leads to a question: looked at the yanmar book and it shows the harness ground on the starter as well as the starter battery ground. This is not my case. My harness ground is to a harness clip above the starter which is where the corrosion was. The starter ground was attached to back of engine on the bell housing bolt. Is the bell steel or alloy? Couldn't get starter bolt loose since need some other tools at home. Think I should make these changes? Want to since one less foot to starting circuit.

 

[Blitz]

Blitz...
When it doesn't start, does it do anything?
Any noise?
Paul

It starts to almost crank for a fraction of a second.

 

[Blitz]

Are you at a slip? Maybe your batteries look fully charged in the morning because they just came off the charger. Are your batteries showing full charge after sailing? Have you reconnected all battery cables at the batteries? It is simple and quick to do and rule out. Use some dielectric grease to prevent corrosion.

After cleaning today I went sailing. Everthing was off except drain from navigation instrument (minor on house batteries). Voltage was 12.8 volts on the house bank of two type 27 batteries (1.5 years old) , 13.1 on the starter battery (2 years old).