On Sunday, July 12, 2020 at 3:13:50 PM UTC-7, wrote:
For those who own Ventus Cm: have you ever measured the voltage on the starter when it is running?. Mine, with fully charged battery, while electric starter is running, voltage on battery fall out to 10volts, and on starter I measured only 6 or 6.5 volts. I have a voltage lost of aprox 2 volts over the positive wire and 1.5 over the negative one. Is that normal? I have starting troubles sometimes and i think it is because of it. What can you tell me about it?

The inrush current demand of a starter can be as much as 150 amp. Obviously, any resistance in the circuit (and I do mean any) will result in a substantial voltage drop, but not 3 - 3.5 V. You have a corroded connection somewhere. Replacing the cables WILL NOT solve the problem (unless they are damaged). You must find the bad connection(s). Taking everything apart and polishing them down to bright metal is the solution.

Your battery is bad and needs to be replaced (no surprise there). Typically they have 10 milliohms of internal resistance which means a 1 V drop at 100 amp. Any more means the internal resistance has gone up to the "toss it" level.

Tom