Starter wont engage flywheel.

[Bt Doctur]

With a counter rotation motor you use just the opposite ,With rear entry starters
For a reverse rotation motor you use standard starter and for a standard rotation motor you use a reverse rotation starter

 

[dubs283]

With a counter rotation motor you use just the opposite ,With rear entry starters
For a reverse rotation motor you use standard starter and for a standard rotation motor you use a reverse rotation starter

OP says engine is LH rotation and the flywheel is rotating counter clockwise as looking forward. Based on the posted pic the package appears to be a straight inboard so it is correct

Only caveat I have is a lot of twin inboard boats have the starboard engine be RH rotation. OP claims it is LH rotation, unless proven otherwise my thoughts are ignition or fuel supply issue(s)

 

[Bt Doctur]

Easiest way is by the firing order. Wondering if its a V drive configuration?

 

[Confident Noob]

What does the inside of the distributor cap look like?

There's a bit of rust inside the distributor. Image attached.

 

[Confident Noob]

OP says engine is LH rotation and the flywheel is rotating counter clockwise as looking forward. Based on the posted pic the package appears to be a straight inboard so it is correct

Only caveat I have is a lot of twin inboard boats have the starboard engine be RH rotation. OP claims it is LH rotation, unless proven otherwise my thoughts are ignition or fuel supply issue(s)

Correct. Both motors are stamped LH. Rotation is good. Based upon weak spark after pulling a plug, it's looking like ignition issue.

 

[tpenfield]

We need the serial number of the engine(s), but I'm thinking L29 w MEFI-3

 

[tpenfield]

There's a bit of rust inside the distributor. Image attached.

I had one of those distributors go bad on my twin 7.4's. One day the engine was running, the very next day it would not start.

I replaced the distributor, problem solved. If you can verify no/weak spark, then you may want to replace both distributors based on the engine's age.

 

[tpenfield]

Here is the link to my thread about no spark . . . FWIW . . .

https://forums.iboats.com/threads/mercruiser-7-4-lx-mpi-wont-start-no-sparky.738651/

 

[dubs283]

There's a bit of rust inside the distributor.

Pretty normal patina pictured there, guessing this is a fresh water boat?

I'm more curious as to what the contacts in the cap look like.

The Delco est system is pretty simple and bullet proof, only other components aside from routine tune up parts that commonly fail are the ignition modle and the wiring associated with primary signal and power/ground supply (usually from corrosion).

Weak spark could be from the coil (uncommon failure) and associated wiring or a poor contact between the module base and the distributor base plate. Merc sells a special "grease" that needs to be applied between the two or issues can occur, especially if the contact is poor

Nice fact is you have a parts room right in your bilge with the sound running engine next door. After you troubleshoot the issue you can verify almost instantly. Just don't be too quick to simply replace parts, figure out the issue and test accordingly

 

[tank1949]

Ok, significant update. Starter is turning the flywheel, and rotating the engine, but engine doesn't even begin to start up.

Did you replace or move distributor/wires? If Chevy V8, bring #1 cylinder to top on compression and check where distributor rotor is point to.

 

[stresspoint]

how fast is the motor spinning over ?.
im guessing your battery may be a little low on grunt or the cabling is not quite good enough foe good battery power , i did read you cleaned the terminals and connections but that does not fix a dodgy cable.
use a secondary battery and a jump cable direct to the starter and see what happens.

 

[tank1949]

ull # 1 plug wire and check for FIRE!

 

[Confident Noob]

Thank you everyone for the help! I'm back on the boat, and working through the testing process for ignition system now. I swaped the the cable that went from the coil to the center cap with one of the plug wires, pulled a plug, and grouded it to test for spark from the coil. I got a little tiny yellow spark and some faint smoke. So, at least I've narrowed it back to coil.
Is there a way to test the coil with a multimeter to confirm its bad and not something else like ground circuit? Picture attached.

 

[alldodge]

Testing

 

[Confident Noob]

Fantastic! You rock.
Appears to pass all tests.
2- Infinite 3- .3 ohms 4- .3 ohms 5- 8070
If this is passing, what would I possibly check next?

 

[alldodge]

Check the Dizzy

 

[Confident Noob]

Check the Dizzy
View attachment 379498

So I tested spark with a cable and plug off the ignition coil high tension post (a) from the other image above, and had very faint spark. That should mean my issue is at or before the ignition coil right?

 

[Confident Noob]

Check the Dizzy
View attachment 379498

Dizzy passes all tests as well.

 

[alldodge]

That should mean my issue is at or before the ignition coil right?

Not necessarily, a weak spark can be the Distributor control. The Dist in simple terms contains a fancy switch. The coil + side has power and the - side is grounded thereby collapsing the filed and the spark is released.

A weak spark can be that the module is not working correctly. With the coil and Dist testing out correctly, it may be the module. Issue with the module is no way to test it

With key ON and while cranking you need to have a full 12V on the Red wire at the coil. If voltage is there then the Dist module would be my next try

 

[stresspoint]

distributor cap cracked ?.
dizzy not grounded well enough.
weak battery.? did you replace older battery's with new or used newer ones were they load tested.
again ? , how fast is the motor spinning over.