That's a very difficult question to answer. It depends on the tightness of the engine, compression, the internal resistance of the starter, and several other factors. I've seen current draw in excess of 300 amps at times when doing a diagnosis of a 6 volt starting system. Very few ammeters exist that can measure current that high, but there's a work-around. Use a voltmeter to measure the battery terminal voltage during cranking, and then use a carbon pile battery load tester to pull the battery down to the same voltage and check to see what amperage that requires. If a starter ever bogs down where it can't spin up to full speed for whatever reason (usually low battery voltage) the amperage draw skyrockets and can do major damage to a starter in just a few seconds. Never, ever keep grinding on a starter as the cranking speed slows down- - - - -stop beating that dead horse and find out why the cranking speed is dropping.
Jerry
