Finding a strong enough solenoid..... help

[Shadow_storm56]

Again with perkins lol.... few years ago the original starter solenoid burnt out and they put a new one on but the new ones my starter guy have just aren't strong enough. They burn up the contacts in a few starts.
So then I'm left using a steel bar to make the contact.

I attached a picture with the new one and a picture of my other perkins with the original style.

I'm gunna look online too.. maybe ebay

 

[Shadow_storm56]

I'm gunna try adding a 500A 12v Dc starter relay in line. That should do it lol

 

[GreensvilleJay]

If red( 1st pix) is new, you should replace all the wires going to it... ANY corrosion on those wires is bad news....

 

[Shadow_storm56]

If red( 1st pix) is new, you should replace all the wires going to it... ANY corrosion on those wires is bad news....

True although it's not a wire issue as if I cross the terminals in a way that engages the solenoid but also sends power to the starter to spins the engine no problem. With just the solinoid the starter just engages the flywheel but can't turn it. Put a new solinoid on and it works for a while but then you end up back at burnt up contacts inside the solinoid again and no start.

 

[jaxs]

True although it's not a wire issue as if I cross the terminals in a way that engages the solenoid but also sends power to the starter to spins the engine no problem. With just the solinoid the starter just engages the flywheel but can't turn it. Put a new solinoid on and it works for a while but then you end up back at burnt up contacts inside the solinoid again and no start.

You might think wires aren't an issue but if cables are in poor shape or too small to carry full load that will cause contacts to get hot and eventually fail. Cleaning up and replacing cables isn't expensive so doing it it might be good insurance.

 

[GreensvilleJay]

When was the actual starter serviced and rebuilt ? If never , how many hours on it ?
'Little' details like worn brushes, weak field coils, worn bearings ,bad armature can keep the starter motor from actually spinning the engine over. A fraction of an ohm can prevent the 100s of amps needed to turn over the engine.
'burned up the contacts' means a LOT of current is going through,so I suspect the actual starter needs to be professionally rebuilt.

 

[Shadow_storm56]

When was the actual starter serviced and rebuilt ? If never , how many hours on it ?
'Little' details like worn brushes, weak field coils, worn bearings ,bad armature can keep the starter motor from actually spinning the engine over. A fraction of an ohm can prevent the 100s of amps needed to turn over the engine.
'burned up the contacts' means a LOT of current is going through,so I suspect the actual starter needs to be professionally rebuilt.

Professionally rebuilt a year ago, brushes checked over the winter and when I looked inside at the brushes nothing was corroded or burnt.

 

[Shadow_storm56]

You might think wires aren't an issue but if cables are in poor shape or too small to carry full load that will cause contacts to get hot and eventually fail. Cleaning up and replacing cables isn't expensive so doing it it might be good insurance.

Fair enough I'll double check as I'm pretty sure they were ok but why not check. I know my ground is fine as that originally was a bad cable... so I went to my local electrical/machine shop and all they had was some massive braided cable that with casing is like 3/4 inch . I said perfect put ends on it. So that's the ground

 

[Shadow_storm56]

I know the engine is a bit extra tough to turn over because of the valve guides... perkins engines seem notorious for wearing them. So when it starts after sitting for a day or 2 there's a small amount of oil in some cylinders. Nothing substantial but enough to raise compression a bit which would create more load on the starter. Had them fixed before but it dosen't last.... plus it makes it start really easy in the cold!

Can't imagine that would cause a super huge increase in starter load though. I did look up that solinoid online and found ones that looked exactly the same, they were only rated at 2Kw which is 170 amps or so. That dosen't seem like alot for that huge starter......

 

[DustyRusty]

Have the valve guides knurled next time and it will save you a lot of grief.

 

[Shadow_storm56]

Have the valve guides knurled next time and it will save you a lot of grief.

Good to know thanks

 

[DustyRusty]

The knurling slows the oil from running down the valve stem since it has to traverse the ridges. I used to work on Chrysler engines that had terrible valve seals. The knurling solves the problem. First, the guide is knurled and then reamed to size, and valves are installed with new springs, umbrellas, and keepers.

 

[Shadow_storm56]

The knurling slows the oil from running down the valve stem since it has to traverse the ridges. I used to work on Chrysler engines that had terrible valve seals. The knurling solves the problem. First, the guide is knurled and then reamed to size, and valves are installed with new springs, umbrellas, and keepers.

Perkins are thoes old style tough as hell engines but.... they have bad valve seals. Or atleast mine all do. Anyways it's kinda funny how it starts in the cold because one cylinder .... likely the main one getting oil in it... will start firing first and it will run like a hit an miss engine for a couple seconds until the other cylinders start firing . Not unusual for a diesel to do this when in cold start... it's just not usually this defined haha.

Anyways as far as the solinoid thing goes idk whare to get a strong solinoid that fits this profile so I ordered a 500A starter relay that I'll put in parallel with the solinoid so when it engages the starter the relay will close at the same time so theres enough current to spin the engine. So it'll have 2 sets of contacts to do the job. The original solinoid worked for quite a long time and actually only failed from water as water was getting onto the flywheel from the attached pump and into the starter. I since fixed that but the original solinoid was already toast.

I'll keep searching for an adequate solinoid in the meantime.... need like a 5Kw rather than 2