Engine slow cranking diagnosis-RESOLVED

[muskyfins]

So on my sig boat-1995 Rinker, 5.7, carb (4 barrel) bravo 2. Cranks slowly. All electrical systems checked-connections good, brand new battery fully charged, brand new plugs, cap, timing etc. Has what I would consider to have high but good compression (135-150 psi). Can't find an hour meter, but PO claims boat had less than 400 hours. I've put on about 6 this year.

But the starter cranks slowly. RrrrR.................RrrrR.............RrrrR..... .....RrrrrR.....RrrrrR....RRRRRRVRoom.

Worse when hot. When I checked compression at the beginning of the season, I thought she cranked a little on the slow side for having all plugs out, but never gave it much thought.

I am heavily leaning toward starter. I don't mind replacing it, but I'd hate to overlook something else and buy a starter for no reason.

Any other ideas? Thanks to all.

 

[Bt Doctur]

solenoid contacts, starter brushes/corrosion, corroded battery cables/cable connections.

 

[Watermann]

Is it the original 1990's huge field coil starter? If so you can't go wrong with a new gear reduction perm mag starter that's high torque and 1/3 smaller. Another reason starters drag like that is the old cable to the battery, they can loose amperage to the starter with age.

 

[muskyfins]

I checked all cable connections and lugs. All good there. This is one of the large case size starters. Was leaning towards bad brushes. Also been looking into the high torque models. So we're all thinking starter. I have some 2 gauge wire (like 100 feet). I might make a brand new cable up and test.

 

[alldodge]

I checked all cable connections and lugs. All good there. This is one of the large case size starters. Was leaning towards bad brushes. Also been looking into the high torque models. So we're all thinking starter. I have some 2 gauge wire (like 100 feet). I might make a brand new cable up and test.

Take a jump box and attach it direct to the starter terminal and engine block ground. If that fixes it you may need new cables or a bigger battery

 

[muskyfins]

Take a jump box and attach it direct to the starter terminal and engine block ground. If that fixes it you may need new cables or a bigger battery

That's an awesome way to do it. Thanks.

 

[Watermann]

If you end up popping for a new small starter, just a heads up the smaller ones take shorter bolts and the originals will bottom out before getting tight. (50 Ft Lbs)

 

[muskyfins]

So, I purchased a new gear reduced Sierra starter from iBoats. After my initial freak out because the new starter has 11 teeth on the pinion and the old one has 9, it worked like a charm. Never had a boat crank so fast and start so easy. Literally, click-vroom. Probably easier on the battery too. Not going to lie, that was a b!tch job. If it wasn't for my college age son with a small bone structure, I would have had to pull the motor. The way it was, we almost couldn't get her done. The kid was contorted and bent in un-natural positions. But in the end, this was the culprit. Thanks to everyone for the support.

PS-the old starter still had a masking tape tag on it with a part number and some fitment info and a $29.99 price tag. Swap meet starter. Not surprised it was starting to fail. But I will have it re-wound and new brushes and keep as a spare.

 

[Watermann]

Thanks for the update. Those new GR starters are simply put ... AWESOME! Glad you're all water ready now with no worries! So I'm wondering if were you able to put in the front starter motor support?

 

[muskyfins]

Been in the water for about a month. We did this job in the slip!

Didn't add the support brace. Next time I replace the water pump impeller, I plan on pulling the motor. Will add it then. Or Maybe during winterization. How many folks actually add them?

 

[Watermann]

I've had 2 Chev trucks 5.7's, same 2 bolt pattern with the big old field coil starters and they din't have a brace. For the small starters you would have fab a new one. I didn't on my 4.3 with the new smaller GR starter.

 

[Bondo]

Swap meet starter. Not surprised it was starting to fail. But I will have it re-wound and new brushes and keep as a spare.

Ayuh,..... Yer kiddin',..... Right,..?? The permanent magnet motors are Waayyy ahead of that antique,.... Scrap it out,....

 

[muskyfins]

Well, I'm kind of a junk collector. I keep a lot of "spare" stuff around. Never know what you're going to need.

So,........ maybe I'll scrap her. One less thing around for the admiral to complain about.

 

[muskyfins]

So it's been about 2 months (and maybe 20 "starts")since the starter was installed, but we haven't used the boat for about 3 weeks. Went down to the slip and she turned over very slowly about one and a half cranks and stopped. I thought maybe the battery was discharged (although it shouldn't have been since it was switched off), so I put her on the charger for about 4 hours. Came back and when I turned the key, you could hear the click of the solenoid, but the starter won't move? It was late and have had a packed schedule so we put the cover back on for now. Tomorrow I'm going down with some tools and I guess the first thing is to check if she's some how seized up. My next guess is the damn starter. Any other guesses? Don't have time to do much diagnostic work this weekend as my brother is getting married.

 

[Watermann]

Resolved? I'm a bit confused here... Ok, so did you put a new starter in and that fixed the issue but now it's not turning the motor over? How old's that cranking battery again?

 

[muskyfins]

Sorry for the confusion. It WAS resolved. Put the new starter in back in June everything was great.........until last Saturday. That's when I got the symptoms above.

Starting battery and the house battery are brand new (June 1). Shows about 12.5V on the dash gauge. (didn't have tools with me or I would have checked with voltmeter). Connections are all good. Cables are all good. I'm pretty meticulous about that stuff. I'm basically convinced it's either the starter or the solenoid. I guess there's an outside chance that the engine could be hydro-locked. But, she hasn't been started for 2-1/2 weeks. I'm thinking any water in a cylinder would have leaked down by now??

 

[alldodge]

Since were guessing I'll take a WAG at the battery. The switch might be off but thinking something is draining it

 

[muskyfins]

Resolved Again---Called iBoats about how to get replacement starter under warranty. They referred me to the manufacturer-Sierra. I was very surprised but Sierra sent me a replacement starter with no hassle at all (especially since I hadn't yet sent them the defective starter) My son and I put the starter in over the weekend and without any additional charging of the battery, she popped right off. In fact, we had removed spark plug wires 2,4, and 6 and she still started right up!!! After realizing our mistake, we shut her down, installed the spark plug wires and all is good.

They say the happiest day in a boat owner's life is the day he sells it, but I was pretty happy yesterday. While I'm satisfied at the outcome, I am disappointed it had to happen in the first place. Yes, Sierra warranted the product and handled it very well, but this was a b!itch of a job. Having to do it a second time was no fun and I lost the use of my boat for two weekends. And of course, now I'm skeptical of how long before this starter fails???