2001 san gt-40

[SAN4Fun]

We were out skiing and tubing today, and I stopped the engine as usual to let someone board the tube. However, when I tried to restart the engine, all I heard was a fast spinning noise, like the starter is not engaging with the flywheel. I had started and stopped the boat several times earlier with no issues. Given that the battery tested fine, the terminals are clean, and the lights and bilge are all working, I suspect the starter might be the problem. Is there any other way to confirm that the starter is the issue? If it turns out to be the starter, how difficult is it to replace in the GT-40? Since the boat is currently in the water at our slip, I guess I would have to tow it to the ramp to get it out.

Edit: I found some videos on replacing the starter but of course the engine is out of the boat, but looks like fairly simple other than having to squeeze into the starboard storage compartment to get to it. Hopefully the starter is the issue and not a tooth on the flywheel. I believe I need a left hand(ccw) starter. Any brand recommendations? (Arco, GT40 Marine?)

[Jonny Quest]

It sounds like the starter is not engaging the flywheel. ARCO is a good brand and a good value typically. Yes, the GT40 is a standard rotation engine (marine). The marine industry and auto industry look at rotational direction differently. Automotive looks at the engine from the FRONT and marine looks at the engine from the REAR. Hence, a clockwise turning marine engine is a "reverse rotation" and CCW is a standard rotation (when viewed from the rear of the engine)

ARCO 70200 is the part number for their starter.

JQ

[SAN4Fun]

Thank you for the information and the part number. I was not sure on the rotation. I am going to attempt to change this out on my own with the boat in the water. We will see how it goes.

[SAN4Fun]

New news. I replaced the battery and it worked. It started and I drove to the marina to get gas and back. I thought the problem was resolved by just replacing the battery, but I got back in the boat today and had the same problem. I tightened all the connections on the starter and on the relay and used another brand new battery that I had bought for a backup and this time it didn't work. Does this working intermittently still sound like a starter problem?

Edit: I noticed that the starter solenoid relay bracket only had one mounting bolt. I assume the mounting plate on the relay serves as the ground. I couldn't get the relay turned to the correct orientation to align the other bolt, so I just tightened the one. I noticed that the plate is not touching the engine on one side. Is one side of the bracket touching sufficient for grounding? Also, are either of the two relays mounted in front of the solenoid relay used for the starter? Could one of those plug-in relays be causing the issue?

Please forgive my ignorance and any incorrect terminology. I'm new to fixing this and all engines.

[SilentSeven]

If the starter spins every time you turn the key, your starter relay is fine.

This short video will help demonstrate how the starter system works: https://www.youtube.com/watch?v=kFsl5r34lCI
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The problem you describe is typically due to one of two issues. Either the starter motor gear is not advancing correctly to engage the flywheel (most likely) or you have section of flywheel with teeth missing (less likely). The starter motor problem can be intermittent which would lead to what you described above. Ground off flywheel teeth is typically caused by repeatedly engaging the starter when the engine is running.

If it was my boat, I'd pull the starter motor and inspect the gear section. It's likely crusty and old. Best bet solution will be a replacement starter motor.

Be sure to disconnect the ground strap at the battery before doing ANY work - there's a massive amount of amperage on the starter and relay cables and an inadvertent short circuit caused by a wrench is no bueno!

[SAN4Fun]

Thank you for the advice and information. The video was very informative. It looks like I'm back to installing the new starter as I initially thought. Fortunately for me as a novice, I can order the exact same Arco starter that's currently on the boat, so wiring and fit shouldn't be a problem. I don't anticipate any issues other than possibly holding the starter in place to align the mounting bolts.

[SilentSeven]

Fingers crossed this solves your problem. Post a follow-up!

[Jonny Quest]

It could also be your starter switch — sometimes referred to as a starter solenoid switch. Under $50 and cheap insurance—and as you are already doing the starter motor…

JQ

[SAN4Fun]

I installed the new starter yesterday, and it was surprisingly easier than I expected. I have previously replaced a starter on car, which was pretty difficult mainly due to accessibility. I just assumed this one would be even more challenging. Fortunately, I was wrong. The new starter seems to have resolved the issue, but since the problem was intermittent, I'm cautiously optimistic. Just in case, I went ahead and ordered a starter solenoid/relay to have on hand.

Thanks for everyone's input!