Something happend to my other post and I cannot edit it. so here it goes again:

Should there be a ground strap between motors? I had a problem with a bad ground and fixed it but noticed that each battery has a ground cable going to each respective block only. The battery switches can use either battery or both together. It seems to me there should be a cable between the two blocks so if you use just the alternate battery to start the engine it dosent have to pull ground through all the other cables. There is no frame in the boat like a car to pull a common ground from. Any Ideas or am I missing something.

My boat has a ground strap between the two blocks. It was removed when I put on the headers. Seems to start just as well with or without it. I'll probably put it back on (between the heads), but don't think it is a "must".

-Greg

on a boat, a lot of times there are multiple ground straps running around to combat electrolysis. Keeping everything grounded with short straps keeps electrical potentials to a minimum.

Not a huge deal on a trailer/lift boat in freshwater.

I think a lot depends on how the manafacture terminates there cables. For what it's worth mine have a cable between the motors. Scott

Or you could just run a ground strap between the two batteries.

I too have a ground cable between the two motors.

Thanks, I think I will put a cable between them, Seemed logical to me.

If I remember correctly, it's called "ground potential".
That's why it had the strap between both engines when new.
Electrial engineers have a field day with this.

Ray you got it right, heavy gauge ground is a must have between the engines. Picture this, bat switch on both, port battery dead, crank the port engine. The ground path for the starb battery will be through the instrument harness and any other misc grounds.

If you have race mounts then the current would flow thru the stringer via the mount bolts in the angle clips, to the next motor mount! But there is a second possibility much worse and it is ,thru the gimbal and bushings cv joint then the drive unit and across the tie bar then back again,Man not nice at all ! also current would be in the welding range when starting!!

Ah lets see thru inside tie bar via tiller arms,thru back thru coupler flex plate then the crankshaft bearings to the engine block .that would be badd real bad ! tell you what just put the ground back on !