Re: 25 hp starter spins but wont pop up/engage
First off make sure that battery is fully charged, 12.65 volts. Then make sure all connections are clean, make them SHINE!! Check all wiring for kinks, nicks, abrasions, etc.... or buldges, that is a sign of inner corrosion. Most of these problems are wiring or connection related. Try turning the starter by hand 1/4 turn, if that sorts it out, the brushes may be shot, and the starter needs a rebuild, done by most starter repair shops, and alot cheaper than buying new. But charge that battery first and let us know what you find. Just another test. Get yourself a multimeter and measure the voltage at the starter (+) terminal while somebody turns the key over to "start" - if you get within half a volt or so of the battery voltage, the starter is faulty.
Bad voltage at starter (with clean tight connections), measure the voltage at the solenoid small terminal with the yellow/red wire with the key turned over to "start" you should read within a half-volt of battery voltage, otherwise you have a wiring fault beween the keyswitch & solenoid. Good voltage at solenoid but bad voltage at starter means faulty solenoid.