Kubota B7300 hard to start

[finz1975]

I have a B7300 that is very difficult to start. I just put a new battery in it and it still does not want to turn over. Any suggestions? Thanks.

 

[85Hokie]

I have a B7300 that is very difficult to start. I just put a new battery in it and it still does not want to turn over. Any suggestions? Thanks.

make sure that ALL the connections are BRIGHT and TIGHT! A poor connection anywhere in the circuit will "look" like a weak battery

 

[North Idaho Wolfman]

More info needed.

Is it cranking slow?
Is it smoking out the exhaust while it cranks?
Is it smoking out of the crankcase breather tube?
Color of the smoke?
When was the last time it had a full service?
How old is the fuel?
How long are you running the glow plugs?
What is the temp outside?

 

[finz1975]

It is slow cranking.
It does not smoke while cranking.
It had a full service about 50 hours ago. Beginning of summer.
The fuel is about a month old.
Running the glow plugs 5-10 seconds.
The outside temp is about 50 degrees F.

 

[finz1975]

Connections at battery are all bright and tight.

 

[85Hokie]

Connections at battery are all bright and tight.

before the new battery, was it hard to start? HOW did you get it started before?

Do you KNOW the glow plugs work? How many hours on the tractor?

this new battery......what is the exact voltage with a "good" VOM?

here is what I would do - jump the existing battery with your car/truck, with throttle at 50% and glow the plugs for 30 seconds or more.....

does it spin faster?

is there any smoke?

 

[finz1975]

before the new battery, was it hard to start? HOW did you get it started before?

Do you KNOW the glow plugs work? How many hours on the tractor?

this new battery......what is the exact voltage with a "good" VOM?

here is what I would do - jump the existing battery with your car/truck, with throttle at 50% and glow the plugs for 30 seconds or more.....

does it spin faster?

is there any smoke?

Before I pout the new battery in, I had jump started it.

I'm not sure if the glow plugs work.

I will have to check the battery voltage.

When I try to jump it, it does not really spin faster.

There is no smoke.

 

[85Hokie]

If you place another battery in the circuit, and there is no change in spin rate, either the wiring to the starter is "weak" or the starter itself is weak. There could still be a bad ground.

To test you glow plugs, you can test them via an GOOD VOM, their resistance is very low.....you can also hit the glow plug switch and see the spot in head increase with a Digital Infrared Thermometer - it might take 30 seconds or more.

You can test the starter by bypassing all the wiring but ground.

Make sure you are in N and have someone sit in the seat with foot on clutch/brake what ever it has.....

Take one end of your jumper cable and place it right on the starter pos. post, hook the negatives up, and then place the remaining hot to the known good battery.....

if there is a change in the starter behavior then you have found your problem (wiring), if it still spins slow - I would suspect a starter problem.

 

[lugbolt]

Probably starter, or ground. Have had to replace several starters over the years. But before buying new starter, I'd highly suggest doing a voltage drop test in the wiring, then test the ground as well. You want to eliminate as much other stuff as you can before buying that expensive starter.

 

[Dave_eng]

Go to this site with starting system troubleshooting tips by DENSO a big name in electrical items.
It shows you how to check for voltage drops in cables and other components and may help narrow down your problem.
http://densoautoparts.com/sites/default/files/tech-tips/DENSO Starter troubleshooting tips.pdf
Dave M7040

 

[finz1975]

I put on a new ground. I pulled the starter and tested it. It appears to be fine. The tractor still turns over slow. I have also jumped it at the starter. The tractor has about 900 hours.

 

[North Idaho Wolfman]

If it's turning over slow and you have made sure the battery load tested good, you either have a bad starter, or bad bearings (seized bearings).

Most likely you have a bad starter, worn bearings in the starter or a bad field will still spin fine without a load on it.

 

[sitdwnandhngon]

I think bad starters tend to sneak up on people, they don't really just go out, they tend to just get slowly worse over time.

In a gas engine it usually doesn't matter too much, once it gets to that point in your diesel, and you swap it out the first thing you think of is "Wow, I can't believe how much faster this one spins"

Lots of load on the starters with those higher compression engines.

 

[farrelmh]

I put on a new ground. I pulled the starter and tested it. It appears to be fine. The tractor still turns over slow. I have also jumped it at the starter. The tractor has about 900 hours.

Mine also started slow.. i removed the ground. and Positive from tractor, prepped the ground location with a wire brush and put new wires on both, and found a loose connection on starter.. spins fine now with a good battery.. also if you have a decompression knob.. you can pull that so the motor spins a little faster and then let it go... ( read that on this form )

 

[finz1975]

Mine also started slow.. i removed the ground. and Positive from tractor, prepped the ground location with a wire brush and put new wires on both, and found a loose connection on starter.. spins fine now with a good battery.. also if you have a decompression knob.. you can pull that so the motor spins a little faster and then let it go... ( read that on this form )

Where would the decompression knob be?

 

[farrelmh]

Where would the decompression knob be?

Mine is located to the left of the steering wheel, its a 1985 L235 so its different.. i'm not sure if your's even has one... some of the other guys on here would be able to answer that for you

 

[North Idaho Wolfman]

The B7300 does not have a compression release, that's only on older model tractors.

Are you pushing the clutch in when you are trying to start it?
If the clutch safety switch was bypassed that could cause it to have unwanted drag on start.

 

[finz1975]

Yes, I was pushing in the clutch. I pulled the stater and took it to the parts sore for testing. They said that it functioned, but probably didn't have the strength to start the tractor. Taking it tomorrow to get rebuilt.

Thanks for all the help.

 

[finz1975]

Put on the rebuilt starter and it fired right up. Thanks for all the help.