Starting battery for Johnson ignitions

I remember hearing on here that older Johnson motors need a more powerful battery than normal for proper spark to start. What is the truth to this?

I am going to be setting up a 1958 50HP V4 and a 1973 115HP V4 in the near future.

What do I need for a battery? I usually buy the biggest marine deep cycle battery walmart carries. Can I get away with a mid sized marine deep cycle battery?

Do I need an automotive type battery for starting and a deep cycle for acc'y? If so how (big)of an auto battery(lead acid?)

TIA

Re: Starting battery for Johnson ignitions

on my V 4's i like to run a 1150 MCA marine cranking amps. group 27 marine starting battery, they are bigger and have more reserve. don't use a deep cycle for starting. the engine put out enough to maintain the starting battery, if you have a lot of assy, go to deep cycle for them.

Re: Starting battery for Johnson ignitions

The 70's motors do not have regulated rectifiers unless they are updated. If you have the stock unregulated rectifier you will be much better off with a large deep cycle dual purpose marine battery.

Many starting battery's, including the ones sold here, have instructions in their specifications not to use them with unregulated charging systems.

Deep cycle batteries can stand more heavy recharging and will generally last much longer because of it. They also tend to act as regulators on unregulated charging systems.

Remember that a starting battery is to be used only for starting. You can use the deep cycle dual purpose marine batteries for everything, including starting.

Edit:
BTW, In terms of comparing batteries "marine" does not mean anything because there is no standard for the term. CCA is a rating that all batteries carry and is rated at 0 dgrees F. MCA on the other hand, is rated at 32 degrees F, and is more difficult to compare because many batteries do not state the rating in MCA.

Re: Starting battery for Johnson ignitions

Several months ago I saw in a thread that some batteries didn't allow the starter to turn the motor at enough RPM's to spark strong enough.

Is their a minimum rating of CCA or something that I need to look for?

Re: Starting battery for Johnson ignitions