View Full Version : Battery amps?

12-02-2004, 12:49 PM
Hi Team Talk board,

I am a new owner of a 1990 PS 190 with the Ford 351. I am in the process of rebuilding much of the boat and have started with the wiring. I have essentially finished now that I have replaced all the wiring on the motor and all other wires from the dash back. I have a battery that I borrowed from my outboard that has 700 marine cranking amps and 550 cold cranking amps. It seems to turn over very slowly. What CCA's would you folks recommend? I was thinking of 850 CCA's.

Any suggestions would be appreciated.


12-02-2004, 02:15 PM
That should be enough amps to get the motor started. Are all your battery connections new? I had a problem last summer with low amps getting to the starter. I ended up replacing the battery connectors with the high end ones from a stereo shop. Now the motor spins right up.

12-03-2004, 03:55 PM
I have cleaned and tightened all connections. I pulled the starter last night and am having it checked today to make sure it is not the problem. I think I need more CCA's anyway, but want to make sure it's not the starter motor first.


T Scott
12-03-2004, 05:49 PM
I think you ar on the right track by testing your starter. In my experience, with a good battery and slow cranking, it has turned out to be a starter problem. A new starter isn't all that expensive and is easy to install. Good Luck!

12-03-2004, 06:14 PM
I think i read somewhere a post from JimN suggesting at least 650 cranking amps.
The more the better...

12-03-2004, 06:39 PM
650 cranking amps is about right. cranking amps = marine cranking amps.
To make them equal CCA divide by 1.28.

Most people think they need alot of cca's weather it be a car or boat; however a lower cca battery(around 500-600) will last longer as the interal plate are thicker. The battery manufactures gain cca by adding more plates thus making them thinner. Batteries normally fail from a dead short when one plate breaks and contacts another. When the plates are thin as in a high cca battery this tends to happen easier.

As always you can not stress enough: CABLES AND CONNECTIONS.

I use to work for a large battery manufacturer and a good amount of the batteries that came in under warrenty were actually good. People just replaced the battery first as it is normally the cheepest and easist thing to change. I'm glad to see you are looking beyond the battery to the cables and starter.

Just my .02

12-03-2004, 06:41 PM
The cranking amps depends on the motor, assuming everything else is OK. If the starter comes back and they say it's fine, check the battery for capacity. If it's an old battery(either one), try it with a fresh one. A fully charged battery will put out the CCA but one that has been fully discharged will never do it again. Every time a battery goes to 0 volts, it loses about 30% of its capacity. After 3 times, it's down to about 34% of it's former self. If it started at 650 CCA, you're down to 223 CCA. That will kill your starter.

If the starter and battery are OK and have checked the cables out, finding no problems, I would remove the plugs and turn the motor over by hand by attaching a 1/2" drive ratchet (a fairly long one if you have that) onto the crank pulley bolt and turning it clockwise as you face the front of the motor. If it's really tight, it needs some lovin'. It shouldn't take a lot to turn it over with no spark plugs in it. If it's really cold when you do this, it'll be harder to turn over.

If you check the cables, measure the voltage from the clean + terminal to the - terminal, then from each successive point in the path from the + to the starter solenoid(s). It could be as simple as a bad solenoid or a corroded/loose nut on the stud.

12-06-2004, 01:14 PM
Thanks for the replies everyone,

I put a new battery in (900 CCA's) and got the motor fired up on the weekend. It's cold here (right about freezing) and the motor has not been running for about two years, I think. It may have been a little tight which could have been part of the slow cranking problem. I removed the valve covers prior to trying to start it and poured oil down all the valve stems, push rods etc. and removed the plugs and sprayed fogging oil in the cylinders. It spins easily now and seems to run fine. I won't really know until spring.

Thanks again for the replies. I'm sure I will have lots more questions as I rebuild this boat. This is a great site.


12-06-2004, 01:32 PM
You could have told us that it hadn't run in 2 years. That makes a big difference. Have the alternator and starter checked out. Condensation beats the crap out of these. Also check the timing to see if it's stable.

12-06-2004, 05:26 PM
Does not running for an extended period make a motor 'tight'? The timing is right on, the alternator seems to be functioning well (according to the dash voltmeter) and the starter checked out fine. At a minimum I have cleaned all electrical connections on the motor and replaced a lot of them as there was a lot of corrosion evident.

If the motor is tight as a result of not running for a while, how long might it take to loosen up and is there anything special I should do during that time? :eek:

Thanks again for any input. There are lots of knowledgable people on this site.


12-06-2004, 05:56 PM
Not running for two years is the reason motors should be fogged before storage. It's cast iron, right? If there's no oil, grease or otherwise water resistant coating on the cylinder walls, valves & seats or rings, they can rust badly enough to create a bad seal or, in the case of the rings, the ring can catch the edge of the groove and cause more problems. Just sitting can also let any moisture in the lubricants get to the metal parts in contact. I have seen boats sit and when started again, the drive gear on the rear of the cam and the distributor gear were corroded so badly that the teeth in contact broke off. That's the reason I brought up stable timing. It sounds like the motor in your boat was maintained well and may have been prepared for sitting. Or, you got lucky with it.

12-06-2004, 08:27 PM
If the motor is tight as a result of not running for a while, how long might it take to loosen up and is there anything special I should do during that time? :eek:

Prayers and special offerings to the boat gods! ;) There isn't much, but since you did get it running I would check the oil often and be ready to change more often. If it was rusted that will be ground off quickly and mix with the oil or out the exhaust. You could do a compression check also.

Good luck, I really feel you're ok.

12-10-2004, 02:30 PM
Thanks for the replies,

I was away for a few days and now it's pouring rain here so I won't be able to fire it up again until it stops raining. I did pull the distributer, prior to turning it over, and looked down the hole. I saw no sign of any rust. I hope the motor is O.K. I won't know for sure until I can get it in the water and start dragging some skiers around. If it consumes a ton of oil or lacks power then I will have to pull it and do a rebuild. Let's hope not.

I need to get on with refinishing the exterior and then the interior. It will be quite a project.