1999 200 ocean pro wont turn over continuous

[jewl]

Im very stumped. Ive replaced the starter, batteries, cables to the battery switch. Took switch apart and it was fine. Have not replaced cables from switch to solenoid or the solenoid. If I install a 1000 amp battery it turns over fine. If I install 850 amp brand new charged battery it will only turn over about 3 o 4 revs then stall and then 3 or 4 more. I thought a solenoid is either totally bad or totally good. Can the inside of the solenoid be corroded and only let some voltage through?

 

[Docksidemarineservices]

You need to check for voltage drop and amperage draw at the starter.