twin dt 140's, '99 . starting issues

[Solarman]

Problem I have it's with both starters engaging the flywheels. the only common link between both motors and both batts is trim tilt. I replaced the switch on the throttles that ties the tilt/trim to one motor, or two. All was fine and working for two, or three trips into the river, so we decided to go offshore fishing. Launched the boat tired to start, and neither motor would do more than spin the starters. Not fast enough to engage the flywheels. Pulled our vehical batt, and jump started both motors. Everything working fine again. Went 35 miles offshore fishing, came back late so cleaned up boat next morning, both motors worked fine. the following week prepped the boat for the river, and motors didn't engage flywheel again. Replaced both batts with higher amp batts, same problem.tried charging batts, jump starting, and still not working.
We have no dual battery switch, and the only common is trim tilt?
Any thoughts would be helpful? All connections at batts, checked and rechecked.

[NealTrombley]

Problem I have it's with both starters engaging the flywheels. the only common link between both motors and both batts is trim tilt. I replaced the switch on the throttles that ties the tilt/trim to one motor, or two. All was fine and working for two, or three trips into the river, so we decided to go offshore fishing. Launched the boat tired to start, and neither motor would do more than spin the starters. Not fast enough to engage the flywheels. Pulled our vehical batt, and jump started both motors. Everything working fine again. Went 35 miles offshore fishing, came back late so cleaned up boat next morning, both motors worked fine. the following week prepped the boat for the river, and motors didn't engage flywheel again. Replaced both batts with higher amp batts, same problem.tried charging batts, jump starting, and still not working.
We have no dual battery switch, and the only common is trim tilt?
Any thoughts would be helpful? All connections at batts, checked and rechecked.

have you tried to just isolate each engine to one battery and..you could still have a bad ( new) battery or something is draining them..

pretty easy to find the issue with taking each motor and trying on each battery and then the other...your TNT should have nothing to do with battery drain..not sure why you are not putting the STB motor and stbd TNT on the stbd battery and same on the port side..I would invest in a battery switch and charger...make life easier on the poor batteries we have today

[Solarman]

starter issues, '99 dt 140's

As I stated the only common connection between stbd & port motors is that one switch at the throttles that allows you to TNT one or both motors at same time. So each TNT for each motor is on it's own battery. Maybe I should wire both TNT units to the same /one batt?