cooltoys61

I raised comp in my 454s to about 9.2 and changed to a roller cam with possibly higher cranking comp so now my 2 500 CCA batts used together will not do it. I bought an 800 and replaced one of the 500s and that helped alot but still won't spin well. Guess I'll add the other 800 and be good but wondered about these high torque starters and if the are actually diff on boats for explosion resistance. Any sources for good deals and how much real torque increase would I get and is it because of the gearing and would still crank slow??

blue thunder

I agree with sutphen, something else is wrong. Assuming the starter/connections are ok, you should check compression and timing. I just cranked over my second of 2 freshly built .070 over 454s with about 9.5:1 and it cranked great with one mediocre battery. The other engine did as well. If something else is wrong and you start bolting up big tq starters you are liable to break/damage something more substantial.

BT

cuda

I have 10:1 and I use normal starters. Check all connections.

mopower

I agree with all the above. Two years ago I replaced my 454s with 540s. Starboard engine always cranked slow. Bought two new 1100 amp batteries .Both had brand new starters. Found loose ground wire on bellhousing of starboard engine.

MrCIG

iTrader: (1)

I agree bad connection somewhere or Timing way off.

Check the back of your battery switches stays damp in there and will corrode

Mark

monstaaa

most people do not up the size of the battery cable when uping the starting/ cranking ability of a boats engine, such as hi-torque starter's and 800/1000 c.a batts. You should really check your ground's, and then replace your cables with 2 ot cables, this your starting system can handle all that extra load. May sound like over kill or unnecessary, but in the long run you'll benefit from it financially, and your starter's and electrical system will love you.

cooltoys61

Good ideas. I had already run a jump to bypass my switch and a jumper to ground the motor. Even jumped straight to the starter pos. bolt??? I am running V6 modules which have 18 initial timing but I pulled the coil wire and it still spins slow. Maybe my heavy #6 ? jump was not heavy enough and I have a problem with a wire somewhere. Won't it be very hot after cranking a while, where the weak link is? My motors have never been grounded to each other, do I need to do that or is that built into the 2 batt switch system ? Thanks

mcollinstn

Motors need to be grounded to each other. There is no ground side provision on battery switches. Neg terminal of the battery goes directly to the engine/bellhousing on each side. The ONLY way you are strapping your batterys' current together is through a) the batt switch on the hot side. and b) the largest common conductor that is connected to both ground wires. With no common ground strap, this means you are sharing starting current through something like the #10 ground bus wire to the house panel or possibly the #8 wires to the trim motors.


#6 is small.

Yes, if you have a wire size or connection issue, then it will be very warm near the weak link (after cranking 15 seconds).

If you pulled the coil wire, you have eliminated an ignition timing problem.

cooltoys61

You da man, again. Thanks guys

fstboater

The jumper cable trick should work use it to the block and to the starter to by pass your elect system. Take a volt meeter and ck voltage while cranking at the starter to ck for voltage drop across wiring and switch clamp on amp meeter to ck starter amp draw look for 300 or less while cranking.