offshore312

Are both engines running the same ancillaries, as in power steering pumps, alternators, etc? I can't help but believe that after complete identical rebuilds that the loss is in the engines at all. Drives, ancillary systems, air flow to engines, and so on, but can't believe engine is the problem...

hickle44

are you checking voltages to the distributors/boxes under load?have you tried swapping the ignition wiring for the distributors/boxes from motor to motor?have you load tested the powers and grounds and checked voltage drop on the wiring to the ignition system?not sure what type of ignition boxes you have but could rfi(radio frequency interference) be affecting the ignition?alternators,plug wires can be hell on crank sensors etc.didnt you say you had a crank trigger ignition?these are some things we see in the automotive field that may apply to your engines depending on your ignition set up.

brian41

Have you noticed while running straight if the rooster tails are even? On the Nor-tech it was easy as I just had to look in the mirrors and adjust the trim accordingly.

Eliminated572

While running straight the port is definitely less roost. Not as aggressive or tall. If I offset the throttles to match rpm they are close to equal at same trim position.

The starboard side has the power steering pump. The port has the stereo. I completely unhooked the stereo/amps for tomorrows test as well. On the last engines I completely swapped all ignition components and netted zero change. I ohmed out the 12v battery lead to starter. 0.00 ohms. Also ohmed out negative battery lead to block ground. 0.00 ohms. Also added 2 new grounds from the main ground to each head. I have not tested voltage under load, only on trailer and getting 14.5 volts while running. 12.8 volts shut off. Both the magnetic pickups in the pro billets are brand new. Both reluctor wheels are brand new. Both engines hold rock steady 34 degrees at idle and revving on trailer.

So to sum up this next test: Drives are swapped. Plug wires are swapped (Again). Carbs are swapped. Coils are swapped (Again). Stereo/amps removed from port battery. O2 sensor installed in port header. Bringing 5 gallon fuel can to run port temporarily from.
I know this seems like a lot of things changed but everything other than the drives I can rule back out on water if the problem moved or cured.

hickle44

I should have clarified on the wiring.have you swapped the actual power and ground wires(if that's even possible) or harnesses between the ignition systems and load tested the wiring not just check resistance?one strand of wire will give you 0 ohm reading on a meter but will not carry the load when there is a draw on the circuit.depending on the circuit we use different sized light bulbs(not a test light) such as a brake bulb or old school headlamp.they pull different loads on the circuit.voltage drop is also an indication of resistance in a circuit.ohms is not always an indication that a circuit is good.also if you have an alternator causing rfi u can just unplug the voltage regulator and retest. you stated earlier you felt like the engine had a kind of a miss.rfi can mess with crank signal inputs.may not be your problem but something else that's easy to try.

brian41

Next time out keep throttles the same and raise the port until roosts are even and see if rpm's match without giving port extra throttle. Then try the same offset throughout the rpm range, if they stay close to the same rpm I bet you have a drive angle from side to side problem.

Eliminated572

Its not the drive angle. I cant possibly trim the port drive high enough to match the starboard rpm wise.... well of course unless I drop the starboard way down. Probably take 4-5 numbers on the indicators if I had to guess. Major difference for sure

Eliminated572

The wires are not long enough to swap from side to side.

Well, I guess for water testing I could take a set of jumper cables from positive battery to starter positive and from negative battery to block ground and compare?? These are the locations my msd/coil are gaining 12v/ground.

You would think the starter wouldnt crank at 34 degrees locked timing if it didn't have a decent 12volt and ground??

Eliminated572

The misfire issue had been cured a month ago. Both engines had it. Mag pickup polarity was backwards. Didn't solved the rpm difference at all.

Questofpower

What he is saying is that the drive is sideways while you are going straight. It may be a very small amount but it doesn't take much to cause an issue. You may have fixed this when you adjusted your tie bar. That would make sense that you pick up more speed turing one direction and not as much (i.e. Make it worse) speed turning the other.