1999 Johnson - Starter spins but doesn't turn over engine

[Codfather]

This morning, I was starting the boat when I heard a "pop" sound coming from the motor. First thing look at the motor and nothing was burning, not even the wires. When I tried to start the engine, it seems like the starter is making a "spinning sound" but doesn't start.
I took the starter and solenoid to a starter mechanic and in front of me, it worked on his bench. He told me your starter and solenoid works and maybe somewhere else.
If someone has seen this or knows what I should try, please let me know. My batteries are fully charged and it worked the other day so I'm not sure what could of done it.

[Codfather]

I fixed it

Just fixed the problem and want to let the community know. Well I went back to basics...I have my boat wired for 2 batteries like most boats but I rigged it with one battery. Well it started and with relief; so I disconnected it and switched over to the other battery and it didn't start. So I dug up a leftover battery that is about a few years old and wired it up, ran the battery charger and now both batteries work. You have to watch out for AGM batteries like mine which is a 800CCA West Marine battery since I guess the gel in the battery popped. There was no visible signs so the pop was internal. I guess the gel or plates gave away.

[Solarman]

Thnx for letting us know.

How old was gel battery, warrantied still? I was thinking of using them?

Again thnx for the input.

[Codfather]

AGM battery

The AGM batteries lasted me 6 years so I got my moneys worth. In fact, I bought 2 more for my boat and they are safer than the batteries with plates in them plus they are self sealed so you don't have to worry about spilling.