Starter Diagnosis confirmation and replacement help

[LaborOfLove]

Hi All - Thought this was finally gonna be the year where everything started smoothly...nope. lol. My 2900 just launched this week. Got her all cleaned up, spent days on the waxing, painted the seats with SEM(which came out AMAZING btw), new vinyl for the cover, made a mahongany table for it over the winter, changed out the engine trim lines and mercathode system for the Bravo II's, and went to fire up the 4.3L carburated engines today. Port side was perfect. Started right up. Had me feeling good, then the starboard took all my good feelings away.

I can hear the engine crank for about 1 second, then no crank and just a whirring sound. It wont crank long enough to start up. Every time i turn the key it cranks for about 1 maybe 2 seconds and then whirrs. Has me thinking the starter teeth may be worn and slipping off after a couple seconds. Does that sound about right? Anything else that could cause it?

I don't think its hydrolocked or short on battery or bad solenoid as the starter spins and the engine cranks for 1-2 seconds every time. Can we rule those out based on that condition? Further, the PO supposedly replaced that starter 3 years ago right before I purchased the boat, but I'm not 100% sure they actually did what they said they did, that said, I assume they did what they said they did.

Assuming I need to replace the starter, its on the starboard side so a total nightmare to get to. I'm tall but flexible, but still looks like a nightmare. Any tips from anyone on if this is doable and how without pulling the exhaust off? Looks like there are some water cooling lines running infront/ontop of the starter, cant even really see the starter right now. Can I pull those lines while shes in the water and just squeeze in there and have at it?

Sorry for all the vague details, but hoping someone might have some practical advice for me. Let me know if you have any other questions that need answering to help.

Thanks in advance!

[mmwjr]

The starter is disengaging either due low voltage or the mechanism that pushes out the starter gear is bad. The hoses you mention are the raw water coming in from the transom to raw water pump then from the pump to the power steering cooler. Removing the exhaust manifold will provide the best access.

[LaborOfLove]

Wow. Fast response. Thanks Mike! I guess it could be low voltage, as the battery was disconnected all winter, but had been charging for the past day. Also was a new battery last year, so I was kind of ruling that out. Would be great if that was the issue, but surely not my luck. At any rate, I'll give it another day of charging and try again.

[speedysprocket]

Yeah, start with making sure the battery is good, then all the cables are solid with clean connections. Remove the connection at the starter to clean it or at least loosen the terminal and wiggle the wire around then tighten again.
I recently worked on a boat where the solenoid would click but starter wouldn’t crank the engine. I removed the two starter mounting bolts and put them back in and it worked like a champ! So the starter had some corrosion or dirt that caused the ground to be very weak.

[LaborOfLove]

Excellent. Thanks for the tip! I’m eager to head down in the morning and see if this clears things up. Had the battery disconnected all winter so maybe wasn’t put back on tight enough.

[LaborOfLove]

Quick update. Went down yesterday and tightened up the battery connections. Battery was a little low, around 12.3 v. But still the engine cranks for a second and then disengages. Going to get a new battery if this one doesn’t charge back up all the way to completely rule that out.

[mmwjr]

Originally Posted by LaborOfLove

Quick update. Went down yesterday and tightened up the battery connections. Battery was a little low, around 12.3 v. But still the engine cranks for a second and then disengages. Going to get a new battery if this one doesn’t charge back up all the way to completely rule that out.

You need to measure the battery voltage while cranking to do a real test. Also try removing the battery cables and cleaning them at both ends.

[LaborOfLove]

Thx. Actually did that. Voltage dropped to the 10.5v range while cranking. Is that bad? Also cleaned the connections with sandpaper just to be sure.

[mmwjr]

Originally Posted by LaborOfLove

Thx. Actually did that. Voltage dropped to the 10.5v range while cranking. Is that bad? Also cleaned the connections with sandpaper just to be sure.

Yes that would indicate a bad cell on the battery. To verify you could try swapping the port and starboard batteries.

[LaborOfLove]

Good idea. I’ll be down tomorrow and give that a shot if need be. I am I correct in assuming by your comment that I can’t just use the switches and set both batteries to the “both” setting? Thanks again for all the advice. You guys are great!

[mmwjr]

Originally Posted by LaborOfLove

Good idea. I’ll be down tomorrow and give that a shot if need be. I am I correct in assuming by your comment that I can’t just use the switches and set both batteries to the “both” setting? Thanks again for all the advice. You guys are great!

Yes you can try the switches in both and it may work but what this does is put the two batteries in parallel and the bad battery will pull down the good one however it may work.

[jrsick]

Mike, are you sure that 10.5V on this test indicates a bad battery? As I understand the cranking volt test; you put a multimeter on the battery terminals and engage the starter. If that's the test he conducted then any reading above 9.5V indicates the battery is providing sufficient power. The 5.0 Manual (#24) has a good section on testing starter motor voltage and voltage drop on page 4A-10. These tests measure voltage between the battery and starter solenoid, and, between the solenoid and the starter. Any reading above 9.5V is a good battery output.
I think his battery has passed the voltage test.

[mmwjr]

I guess we’ll find out when try’s swapping the batteries. A better test would checking the voltage at the starter while cranking.

[LaborOfLove]

Swapped the batteries. Unfortunately no difference. The batteries are good. Leaves me back at the starter. At this point I’m going to have it replaced and will report back.

[mmwjr]

Originally Posted by LaborOfLove

Swapped the batteries. Unfortunately no difference. The batteries are good. Leaves me back at the starter. At this point I’m going to have it replaced and will report back.

Have you verified the voltage at the starter when cranking? Using the engine block as the return? While it may be the starter corroded or loose battery connection of either positive or negative at the engine could be the issue.

[jrsick]

The 5.0 manual has testing procedures to isolate the problem to starter, solenoid, or battery. Not sure if the 4.3 manual has same info.
Do you see the crankshaft turn when the starter is first engaged?

[LaborOfLove]

I haven’t gone so far as to troubleshoot the solenoid. It’s so hard to access my thought it to just replace the whole thing and not have to deal with it again. The engine turns, but the starter slips/disengages after a second or two every time. Every time it turns for a second then disengages. Makes me think it’s not a bad tooth on the flywheel(which seems like that would be worst case scenario), not battery, not a locked engine. Could be a bad solenoid or loose ground but i tightened what I could. I’m thinking the teeth may be worn on the starter, but guess we will see once it’s out. I struggle to fit down there so unfortunately going to have the marina tackle it.

[mrt214]

Sounds like the Bendix drive in the starter is shot. You can replace the Bendix if you have ever rebuilt a starter. if not just replace the starter.

[LaborOfLove]

So marina pulled the starter. Telling me a tooth is missing on flywheel so whole engine needs to be pulled To properly replace. They are reluctant to just put a new starter back in and telling me it will be a ton of labor to replace the starter since it’s hard to access and the engine may not run after the fact anyway. What do you all think? How many labor hours from a professional mechanic to replace the starter?

It’s only one tooth missing, but I don’t know anything about that. The engine ran fine last year, so I’m thinking we had this problem last year also. Any advice out there? Trying to post the picture they sent me too.

[LaborOfLove]

Pic attached