Starting battery

[lckstckn2smknbrls]

I recently picked up a 1974 Mercury 402 40 hp motor with electric start. The motor is going on a 10' hydroplane so battery size and weight are important.
What is the smallest Cold Cranking Amp battery that will start this motor?
I'm thinking about a battery for a lawn and garden tractor.
Thanks

 

[Texasmark]

Re: Starting battery

Yeah, I was too. They make two sizes internally with the same case size. I think they come in 235ish and 275ish. Only difference is the plate size which would change the weight. Volume is the same. It would be important to ensure that you have a fresh charge on your battery before you go out and that your engine is in tip top shape. Adding some Sea Foam to the gas/gas mix can help to ensure the latter I guarantee you.

Mark

 

[Frank Acampora]

Re: Starting battery



I don't race her but weight is always an issue on small boats. Right now I am using a smaller auto battery.

Yep! Lawn Mower battery is what I am going to try this season on this 10 foot tunnel hull with a 50. Use the thickest gauge cables you can find and fit to reduce loss from battery to solenoid.

Notice the grin? That's what happens when she gets up on step.

 

[WIMUSKY]

Re: Starting battery

A lawnmower battery will work just fine. When I was racing, that's what I used and I wasn't the only one......

 

[lckstckn2smknbrls]

Re: Starting battery

Thanks everyone.

 

[lckstckn2smknbrls]

Re: Starting battery

I've found several batteries on sale at my local hardware store ranging from 235 cca, 300 cca and 350 cca. Would the 235 cca battery work or should I look at the higher cca ones?

 

[ezmobee]

Re: Starting battery

For that size motor the 235 should be fine.

 

[Silvertip]

Re: Starting battery

Price difference as well as weight is very little different. Go for the 350.

 

[lckstckn2smknbrls]

Re: Starting battery

I bought the 350 cca battery.
Thanks

 

[Cowthief]

Re: Starting battery

While on the topic, what cca would be recommended for a Johnson 1986 90hp. I previously have two batteries (550cca) hooked up, the 2nd died and I am looking to replace both of them at the same time as I have a selector I switch between.