Starting issue with a 1991 Cat 3208T-thoughts?

[Prhugret]

My 1991 Jefferson 43 Marlago has twin 3208’s with approximately 2700 hours each. Both engines when cranked roar to life immediately, even after their winter nap. However, the starboard engine won’t crank until the port engine has run for a few minutes. Then she to starts immediately. Things I have don;
1. Replaced the starter 2 years ago when the old one died.
2. Replaced the safety switch associated with the gear shift.
3. New 8D batteries this year
4. Rewired the cable ends with new connectors

I continue to believe i5 is an electrical issue and am thinking of installing a new key switch. Any thoughts other than that would be most appreciated Thank you.

 

[TowLou]

Hrmmmm..... first id see what volts you have at the starter to your starbord.

Same battery for both motors?

Starboard motor will not start first?

Check grounds to starbord engine. Check that all terminal connections are clean.

Verify switch operation when you turn the key at the starter to eliminate that switch.

 

[High Wire]

It will be easier to troubleshoot since it is repeatable at will. Try not to jump to conclusions.