LT1000 starter solenoid getting hot

[bkenobi]

My project tractor sometimes is a bit hard to start. The battery is relatively new and when it's running, the motor runs strong. I don't think the issue is the starter because once it starts spinning it will go for a while if need be. Today I spun it for around 20 seconds hoping it would kick over. I stopped when I noticed a little wisp of smoke from the right side of the hood which I had raised. Upon investigation, the hot/red side of the solenoid was getting hot. The lead to the battery was warm, but the stud on the solenoid was hot enough that it had melted a hole in the rubber cover of the hot lead.

I'm wondering if the solenoid could be the problem or just a symptom of cranking for too long? I've checked other things (plugs, compression, etc) but this is the first I thought of the solenoid. They are fairly cheap and easy to source so if it's a possibility I'll swap it out. Other threads here suggest grounding, corroded contacts, wire gage, etc. I haven't tried those yet but they sound like good options to look into before swapping parts, too.

 

[jaxs]

Two most likly things to cause post and cable end getting that hot is high resistance contact/connection or starter pulling more amps than it should. Since the possability of high resistance is cheapest to eliminate,we'll do that before replacing starter. You cantry everything following except replacing solenoid but contact inside is very likly burned.
If replacement starters DON'T come with new solenoid I would first replace the existing solenoid to see if everything works normally then. In the process of replacing solenoid clean all 4 battery cable ends and make sure all connections are tight. Examine wire inside insulation where solenoid eyelet lug clamps onto cable to make sure it isn't loose,broken or corroded. Ground cable should be connected to a cleaned spot on engine NOT to sheet metal nor accessory. As insurance,remove starter and clean contact points between starter and engine block.
Engaging starter for a normal leingth of time might make cable lug warm but not too hot to hold a finger on. If it does get hot I believe the starter is pulling too many amps.. You can find specs for starter amps and test if you have an amp meter with enough capacity.

 

[Lstlk2hi]

Stuck bendix (throws gear forward to crank flywheel) gear could do it. Or hidden corrosion generally on ground side is more common. Hot side grounds out there are usually signs like smoke, crackle, fire, and finally starter brushes. Stranded cable the corrosion works in both directions so it can hide in the middle and only has like 3 to 5 strands still working. If you can get to it take a jumper cable from positive terminal and clamp or hold it on the starter body copper button. If same then look to wires. If cranks fine you've eliminated the starter and bendix as problems. Be careful of moving belts, open gears and any wiring.

 

[rScotty]

Solenoids get hot. That is normal and completely expected. So do starters. Both run hotter than one would expect. They don't have cooling, they just get away with so much heat because they don't run for long.

Corroded contacts inside the solenoid could definitely make even more heat...but just the solenoid's internal coil by itself is turning a lot of current into heat. Starters get even hotter, in fact. Both have to really gulp down amps to create enough power to crank an engine.

I used to rebuild starters and solenoids... it was easy bonus money for a mechanical shop owner just starting out. When either solenoids or starters fail it is usually because they got too hot and burned the insulation off of the internal coil windings which shorts those windings together - which effectively means that the motor then has less windings and less resistace a combination that draws even more current.
That quickly makes enough heat to burn through the coil-wrap outer insulation and shorts the whole coil pack directly to the case (ground).

The reason why starters and solenoids last as long as they do is because normally the engine starts before the solenoid and starter motor get too hot. They are primative that way. Don't crank too long and give them several minutes to cool off between cranking sessions.
luck,
rScotty

 

[Gator6x4]

The starter is dragging. Remove the starter and take it to a starter repair facility and have them test the starter then repair it. Or buy a new starter and transfer the solenoid. I personally would replace both since you have got the solenoid hot enough to melt connectors.

You can also use a amp meter to check the amperage draw as the starter is spun over and trying to start the engine.

 

[CobyRupert]

20 seconds doesn’t sound like a lot, but I just stared at the wall clock and made a cranking “wrrr wrrr wrr “ sound for a full 20 seconds (ignoring the strange looks from the dog).

That’s a long time!

 

[tomplum]

No, these solenoids should not get hot. Are you experiencing this issue when the starter is attempting to crank over the engine? You didn't say what engine you had. IE if it is a Briggs OHV, you could have a compression release issue.

 

[bkenobi]

It's a 20HP opposed twin Briggs. The tractor started out with a 25HP V-twin Briggs. I don't know the story for the swap, just know how it sits today. The smaller motor seems inline with the other LT1000 of the era having a 42" deck and similar transaxle. Being a smaller engine I assume the solenoid would be ok if it was from the original tractor. Also, I'm assuming the starter is from this engine when it was swapped.

When I try to start it, sometimes it takes a while. It will crank a fraction of a turn (based on the visible top case cover) with a turn of the key. I'll release and try again. Repeat several times and it will eventually turn one or more turns. After a few more times, it will start cranking away. At that point, I may have to fiddle with the throttle and/or choke to get it to fire up. When I say it was cranking for around 20 seconds, that was once I got it spinning so the whole process may have been a couple minutes. Based on comments, it could have heated up the solenoid pretty good in that time.

Sounds like the recommendation is a potentially faulty starter and now a possible start solenoid? The battery is around a year old and claims 300 CCA so I'm assuming it should be good enough. I moved it over from my other tractor before selling it and it worked great there.

TITAN 12-Volt U1 Tractor Battery U1R-3T - The Home Depot

Exide TITAN garden tractor/utility batteries are designed to deliver consistent starting power and reserve capacity (RC) in every season. Whether it's 3 acres of new fescue that needs cutting in the spring,

www.homedepot.com

 

[tomplum]

Yes, I would agree with the starter and a possible solenoid. These starters did get tired and new one is frequently the fix. 497596 If you determine that it's a oil burner, you may have to go a little further.

 

[jaxs]

No, these solenoids should not get hot. Are you experiencing this issue when the starter is attempting to crank over the engine? You didn't say what engine you had. IE if it is a Briggs OHV, you could have a compression release issue.

After I read op's follow up post I feel confident you nailed it tomplum.
OP you should adjust the valves before doing anything else. A perfect battery and starter can't start the engine while valves are out of adjustment.