Perkins 4108 starter bad?

[tradrockrat]

Originally Posted by tradrockrat

First thing I'm going to do is buy a solenoid to have a spare because that's just smart anyway (maybe a whole new starter and make this one a spare?)

Second thing I'm going to do is jump the solenoid with a screwdriver to see what happens. This is also where I'll GENTLY tap the starter with a wood handle (swinging metal wrenches near a starter seems....risky...to me)

Third I'm going to spend money I might not need to spend to replace the negative cables and maybe terminal blocks as well with new ones from the engine block all the way to the battery - those cables could be anywhere from 1-42 years old - piece of mind by replacing them is worth the cost to me.

If it isn't fixed, I'll check for hydrolock, re-read the Perkins manual, and then break out Caulder and get to work.

Ok folks - update.

Jumped a good battery to the starter and then jumped the solenoid with a screwdriver- nothing except a really hot jumper cable. That pretty much says bad solenoid or starter, correct?

Just to be sure, I put a big ole wrench on the crankshaft nut and she turns - not hydrolocked.

I'm by myself, so trying to tap the solenoid while turning the start key might be the funniest looking dumb thing I've tried in a while...lol

I've decided to pull the starter and see where I can get it looked at, AND buy a new one. I'll get the original refurbed / fixed if possible and have it as a spare.

NEW/SAME/TANGENTAL issue: I swear to you all I looked everywhere and the only ground wire I see on my engine goes to the alternator. Well...except for a tiny gauge wire running from a hose clamp on an oil pressure gauge to the top of the engine...sigh...

Hook a fella up and tell me where the ground to the engine block on a 4108 usually is????? I've got to be missing it. Any ideas? I kinda need to know because I'm still going to swap out all cables in the starter motor circuit with new ones - that includes the engine block ground...which I can't find...because why would it be easy to see?

[Cadence]

Originally Posted by tradrockrat

Ok folks - update.

Jumped a good battery to the starter and then jumped the solenoid with a screwdriver- nothing except a really hot jumper cable. That pretty much says bad solenoid or starter, correct?

Just to be sure, I put a big ole wrench on the crankshaft nut and she turns - not hydrolocked.

I'm by myself, so trying to tap the solenoid while turning the start key might be the funniest looking dumb thing I've tried in a while...lol

I've decided to pull the starter and see where I can get it looked at, AND buy a new one. I'll get the original refurbed / fixed if possible and have it as a spare.

NEW/SAME/TANGENTAL issue: I swear to you all I looked everywhere and the only ground wire I see on my engine goes to the alternator. Well...except for a tiny gauge wire running from a hose clamp on an oil pressure gauge to the top of the engine...sigh...

Hook a fella up and tell me where the ground to the engine block on a 4108 usually is????? I've got to be missing it. Any ideas? I kinda need to know because I'm still going to swap out all cables in the starter motor circuit with new ones - that includes the engine block ground...which I can't find...because why would it be easy to see?

The starter does not need to be energized when you tap it to try and seat worn brushes. It is only a stop gap but identifies the problem.

[rbk]

When you say jumped you just connected a good battery directly to the starter and re-used the existing ground? Ground is most likely on the back of the engine but can be to any bolt on the block. I would verify your ground first before buying a new starter. If its the original starter they are very robust and heavy so watch your fingers when removing as it weighs a lot. New planetary starter is 1/4 the weight.

[tradrockrat]

Originally Posted by Cadence

The starter does not need to be energized when you tap it to try and seat worn brushes. It is only a stop gap but identifies the problem.

Than that is probably not the problem. I did tap it a few times, but I was pretty gentle - maybe I'll try it again.

[tradrockrat]

Originally Posted by rbk

When you say jumped you just connected a good battery directly to the starter and re-used the existing ground? Ground is most likely on the back of the engine but can be to any bolt on the block. I would verify your ground first before buying a new starter. If its the original starter they are very robust and heavy so watch your fingers when removing as it weighs a lot. New planetary starter is 1/4 the weight.

I actually uses jumper cables. I connected the + battery to the starter and the - ground to the engine block

EDIT: And I see no ground connected to the back of the engine block. I'll keep looking.

[jkishel]

Originally Posted by tradrockrat

I actually uses jumper cables. I connected the + battery to the starter and the - ground to the engine block

EDIT: And I see no ground connected to the back of the engine block. I'll keep looking.

On 4-108s I’ve seen the ground cable connected at one of the starter mount bolts or under the forward engine mounting bracket, but it could be anywhere on the block. Maybe all you have is the connection on the alternator case which would work but isn’t best practice.

[Cadence]

Originally Posted by tradrockrat

Than that is probably not the problem. I did tap it a few times, but I was pretty gentle - maybe I'll try it again.

I said rap not tap. It may tell you nothing but worth a try. Worn brushes often will not seat all the way. Too much ware and the springs are marginal at getting them the the commutator all the way. JMHO

[tradrockrat]

Found the engine ground cable! It was actually obvious and I just missed it. I will take it off and get a replacement today.

However, I still think I need to pull the starter and try to refurb it. I think it is the culprit at this point, so after lunch and few hours of "work" work, I'll get back to working on the boat.

[Cheechako]

A bad starter is likely the LEAST possibility. Compared with cars the starter is used what... one 50th as much?
-#1 is often a ground cable attached to the engine that is dirty, rusted or oily, making poor connection.
- Of course hydrolock may be an issue, but the low voltage likely indicates something else.
-Beware that there is a plastic multi wire connector on the back of the 4-108 (at least mine had one) maybe 8 wires? Every once in a while it would not connect well either from moisture or engine vibration. Unplugging and plugging it back in cured the problem.
-I removed my starter before going cruising thinking I would rebuild it. It was like new inside other than dust. Zero noticeable brush wear etc.

[Scubaseas]

Jumped a good battery to the starter and then jumped the solenoid with a screwdriver- nothing except a really hot jumper cable. That pretty much says bad solenoid or starter, correct?

Just to be sure, I put a big ole wrench on the crankshaft nut and she turns - not hydrolocked.

Sounds like you armature in the starter is shorting to the field. Rebuild yours or get a new one. If it was bad brush you would not have heat in the cables as you are clearly completing a circuit. Do let us know what the rebuilder says or what you find on opening up the starter.

[Bycrick]

So, you take a good battery, attach it to the starter, and jumper it. Starter does nothing, but wires get hot. Odds are that the starter is mechanically locked up. The little starter motors for our Yanmar engine once came with what was alleged to be a test report. No-load current: 85 amps. Normal starting current: 240 amps. Locked rotor current: 450 amps.

Before I worried about electrical defects, I’d take it off and see it it turns easily by hand.

[tradrockrat]

Update -

The starter came out (that was...fun...) and I took it to a starter / alternator shop just down the road. Didn't even think to try turning the gear. I expect a call from them today with news. I ordered a NEW starter from good ole Amazon and that is due tomorrow at my house, so won't be on the boat until Sunday.

Today I am switching ground from engine to busbar with new cable, and both starter cables - from battery to switch and from switch to starter with new cables.

So... the project will have no resolution until Sunday. My hope is that it was the starter, and the starter gets rebuilt. Then I have a spare.

I'll let you all know the results as I get them.

[Cheechako]

Originally Posted by tradrockrat

Excellent advice everyone. Thanks again. As I said earlier, I'm headed down tonight and I'll make this my Tuesday project.

First thing I'm going to do is buy a solenoid to have a spare because that's just smart anyway (maybe a whole new starter and make this one a spare?)

Second thing I'm going to do is jump the solenoid with a screwdriver to see what happens. This is also where I'll GENTLY tap the starter with a wood handle (swinging metal wrenches near a starter seems....risky...to me)

Third I'm going to spend money I might not need to spend to replace the negative cables and maybe terminal blocks as well with new ones from the engine block all the way to the battery - those cables could be anywhere from 1-42 years old - piece of mind by replacing them is worth the cost to me.

If it isn't fixed, I'll check for hydrolock, re-read the Perkins manual, and then break out Caulder and get to work.

It's also possible that your starter drive was stuck in the flywheel. Loosening the starter may clear that. You didn't try it to see if it turns fine when loose?
I wonder what starter you got on Amazon? There are many non spec starters out there now days. It may be fine but I would expect a real Perkins type of starter to be a lot of money.

[tradrockrat]

VICTORY!!!!!

So here is the the final update. -

The engine is running! I got a call from the Starter repair shop and they said the starter was good, but there was an odd thing - the solenoid is held on with two bolts and a third bolt goes through the "lever" that shoves the starter pawl /gear - that bolt was BENT. I talked to a marine mechanic who was here on the dock today and he said that could indicate it got stuck (que the quote!)

Originally Posted by Cheechako

It's also possible that your starter drive was stuck in the flywheel. Loosening the starter may clear that. You didn't try it to see if it turns fine when loose?
.

The repair shop said this starter works. They inspected and put the starter back together with new bolts for only $20 - so shout out to A-Alternator and Starter in Kemah Texas.

He recommended checking and replacing: new battery, new cables, new switch. - just like all of you said. I told him the battery was good - he said check it anyway (It's good).

So I went and bought all new cables from battery to switch, switch to starter, and engine block to ground. She runs!

[Wotname]

Originally Posted by tradrockrat

VICTORY!!!!!

So here is the the final update. -

The engine is running! I got a call from the Starter repair shop and they said the starter was good, but there was an odd thing - the solenoid is held on with two bolts and a third bolt goes through the "lever" that shoves the starter pawl /gear - that bolt was BENT. I talked to a marine mechanic who was here on the dock today and he said that could indicate it got stuck (que the quote!)



The repair shop said this starter works. They inspected and put the starter back together with new bolts for only $20 - so shout out to A-Alternator and Starter in Kemah Texas.

He recommended checking and replacing: new battery, new cables, new switch. - just like all of you said. I told him the battery was good - he said check it anyway (It's good).

So I went and bought all new cables from battery to switch, switch to starter, and engine block to ground. She runs!

Thanks for the update - great result