Heres the screen shot
Hey mate it was afew pages in 70-100 amp hour for the yamaha 115-130hp
70-100ah battery would be up around the 700cca-900cca i'd think
Heres the screen shot
That's silly of Yamaha. Starter motors care about how many amps you can feed them (CCA) not how long you can feed them (Ah), within reason.
They've obviously assumed standard lead acid battery type and given the typical Ah range required to achieve the necessary CCA. So 70Ah lead acid typically gives ~700CCA (ie that's their minimum recommended spec) BUT you could alternatively achieve that out of something like an Optima D34M AGM, which can push 750CCA despite only being rated at 55Ah.
Or a good lithium jumpstarter might push 1000CCA despite only being rated for 10Ah. Would still be fine.
I've been using a 4S 5000AH Lipo battery as a back up to jump start my 4wd. Does it with ease when the fridges drains it dead. Dunno how many time it will do it, but I would image over 10 starts, and it weighs in at 300grams for $50
Humility is not a weather condition.
If it's a high draw LiPo (say 60C / 120C burst) then you should get ~600CCA from a 5Ah battery and ~720CCA from a 6Ah. Great for jump starts provided the engine fires up pretty quickly - they won't like pushing peak discharge rate for more than about 10 seconds, so don't keep cranking without cooldown breaks if it doesn't want to start.
Pull cords rule, they never go flat, they're cheap as chips and they allow the motor to start easier than than trying to suck the guts out of the flywheel magnets with a 150A starter motor drawing on a 10A charging system.
If you ever get stuck you can make one by unraveling some anchor rope, add a giant grannies knot on one end & tie the other end to a screwdriver.
How much fun is it when the motor fires instantly and your starter rope gets ripped out of your hands and flings around at warp speed, removing skin from hands before the screwdriver gets sent into orbit.........still, it's better than being broken down, or is it?
The first time on my 90HP I nearly chucked myself into the cuddy cabin, I reckon it fired on the very first compression stroke then proceeded to rev it's tits off.
Haha..funny stuff, kind of like elbowing your mate in the guts because he was standing too close watching what you're doing when you pull the rope!
Thanks for making that distinction clear. My 2nd battery in my dual system is a Centery 75Ah rated at 680CCA and that starts my motor.
Need to be careful with the advertising of these Lithium chargers as the marketing hype will say for example 1000A or 2000A, but that's not the CCA they can produce which may be a lot lower, say 400CCA.
Interesting; I did read in the Yamaha manual that in emergency situations it was possible to pull start this 115hp Yamaha. Maybe I should source a rip cord and stow it in the glove box? So tell me, even if the battery is flat, with the ignition key switched to the "On" position, I rip cord will fire up the motor and will run it?