Minimum battery required to start '64 Merc 650?

[matt167]

Want to spin my 650 over but don't have a marine battery, and buying 1 premature, would probably waste money. I checked the electrical system with my battery charger and I'v got power to the control box, solenoid clicks and the chokes hum and close. I had a fire extinguisher handy but didn't need it.. Is my 300 CCA lawn tractor battery enough? or do I need a larger battery? I just want to spin the motor over for compression numbers, and then see if I can get it to fire up if it checks out.. Every time I pull the recoil, the transom flexes bad, so I don't want to put any un needed stress on the fiberglass back there till I can replace the transom and restore the boat. Just doing prelim checks on the motor before I pull it.

 

[Maxz695]

Re: Minimum battery required to start '64 Merc 650?

pull your car battery and use it temporarilly. I don,t think a lawnmower battery is gonna have much for the starter on the boat motor and may cause damage to the electronics

 

[matt167]

Re: Minimum battery required to start '64 Merc 650?

That's what I was thinking, just thought there was a possibility of the 300 CCA battery working.

 

[mr 88]

Re: Minimum battery required to start '64 Merc 650?

Unless your running a lot of electronics a car battery will do the job for less money,if that is your concern.Most of the marine batteries are Dual purpose,so you can run your stereo/ship to shore radio/depth finders/trolling motor/down riggers/interior/exterior lights etc.with a slower drain because of the deep cycle part. I am guessing,most people with a vintage 65 run it on a older 14-17' boat with lights and maybe a depth finder being the only electric drain and rarely go out at night anyway.

 

[matt167]

Re: Minimum battery required to start '64 Merc 650?

Well, I lucked out. Happen to stumble over a battery looking for something. It's 500 CCA, very low reserve capacity, but I think I can warm it up on the charger and perform the tests on the OB

 

[mercurymang]

Re: Minimum battery required to start '64 Merc 650?

I think another purpose of the deep cycle is that it has larger plates and can withstand the higher charging voltages of some of the older motors that have no voltage regulator. I may be wrong on that but i have read something to that effect.