[JonathanP]

I have a vn750 2004 that has trouble starting with only the battery, it has a brand new 14amps battery, but when i try to start it, it sounds like the battery is discharged, but the battery shows 13.4v on off position, 13v in the on position, and it drops to 12 when i hit the start button, but it sounds like the battery is discharged and doesnt starts, i have to put Jumper cables on it to start it, but even if i put the Jumper cables directly to the starter engine it sounds that way, and the battery Charger deliveries 20 amps, it only starts if i put the starter directly to the battery, i have checked and replaced the wiring harness, the regulator, the stator, fuse box, starting relay, and checked the starter engine, everything seems fine, also when it's running sometimes one of the Cylinder goes off and on randomnly.

 

[Spockster]

I have a vn750 2004 that has trouble starting with only the battery, it has a brand new 14amps battery, but when i try to start it, it sounds like the battery is discharged, but the battery shows 13.4v on off position, 13v in the on position, and it drops to 12 when i hit the start button, but it sounds like the battery is discharged and doesnt starts, i have to put Jumper cables on it to start it, but even if i put the Jumper cables directly to the starter engine it sounds that way, and the battery Charger deliveries 20 amps, it only starts if i put the starter directly to the battery, i have checked and replaced the wiring harness, the regulator, the stator, fuse box, starting relay, and checked the starter engine, everything seems fine, also when it's running sometimes one of the Cylinder goes off and on randomnly.

Sounds like the starter could be dragging.

Does the positive cable on the starter get hot?

Did you open the starter and check the brushes and bushings?

 

[JonathanP]

Sounds like the starter could be dragging.

Does the positive cable on the starter get hot?

Did you open the starter and check the brushes and bushings?

Yes i did, i checked the brushes and bushings and it doesnt have anything wrong, not even debris, the starter does get hot but not the cables

 

[Spockster]

Yes i did, i checked the brushes and bushings and it doesnt have anything wrong, not even debris, the starter does get hot but not the cables

Everything seems to point at the starter.

Check to see if the plugs are wet before trying to start. Also see if the oil is overfull. Check the vacuum line to the petcock (center port) to see if there's gas in it. Should be dry.

With the above I'm trying to see if gas could be filling the cylinders, which will make it hard to turn over.

Any reason the cylinders would be rusted?

 

[JonathanP]

Well i just changed the oil taking advantage that i had to take it to remove the starter.
The Cylinders are good, i just did an ring replacement and it was working just fine.
The vacum line is good as well, i just replaced it yesterday also and it was everything good.
I haven't checked the plugs nor the plugs cables.

I did tought that it deffo was the starter, but i checked it, cleaned it, put some grease on the bearings and everything seems just fine in the starter, but it keeps doing the same thing

 

[Spockster]

Well i just changed the oil taking advantage that i had to take it to remove the starter.
The Cylinders are good, i just did an ring replacement and it was working just fine.
The vacum line is good as well, i just replaced it yesterday also and it was everything good.
I haven't checked the plugs nor the plugs cables.

I did tought that it deffo was the starter, but i checked it, cleaned it, put some grease on the bearings and everything seems just fine in the starter, but it keeps doing the same thing

I would load test the battery to make sure that's not the problem. Any parts store can do a load test, it should hold 200-250 amps for a few seconds.

 

[Thorn]

You can get it to start when jumping the starter directly to the battery? That's an oddity. Have you checked the volts at the starter's contacts? or before and after the starter solenoid?

 

[JonathanP]

You can get it to start when jumping the starter directly to the battery? That's an oddity. Have you checked the volts at the starter's contacts? or before and after the starter solenoid?

No, not even jumping the battery directly to the starter i can get it to start, only if i'm using the battery Charger and the battery i'm able to start it.
Yes i have, everything goes as expected

 

[JonathanP]

I would load test the battery to make sure that's not the problem. Any parts store can do a load test, it should hold 200-250 amps for a few seconds.

I Will do that tomorrow at the shop, but again, the battery is literally new, i bought it last friday, because i first tought that the one i already had was the problem, and again, even if i jump the battery Charger directly to the starter seems like theres not enough Charge, and the battery Charger gives 20-25 amps

 

[Spockster]

I Will do that tomorrow at the shop, but again, the battery is literally new, i bought it last friday, because i first tought that the one i already had was the problem, and again, even if i jump the battery Charger directly to the starter seems like theres not enough Charge, and the battery Charger gives 20-25 amps

Sometimes new is not always good. There's a recent thread involving a new DieHard not delivering the amps. It sounded like the second new battery was also weak, but I don't we've heard back on that yet.

That's where the problem is, either the starter is pulling too many amps or the battery isn't delivering. If it's neither of those then the amps are getting lost at the cables.

The next test I would do is seeing how many amps the starter is actually drawing. The same battery tester can do that test.

You said it started ok after the new rings, correct? So we can rule out a tight ring end gap.

If there's not excess gas in the cylinders, everything is pointing to amps.

 

[JonathanP]

Sometimes new is not always good. There's a recent thread involving a new DieHard not delivering the amps. It sounded like the second new battery was also weak, but I don't we've heard back on that yet.

That's where the problem is, either the starter is pulling too many amps or the battery isn't delivering. If it's neither of those then the amps are getting lost at the cables.

The next test I would do is seeing how many amps the starter is actually drawing. The same battery tester can do that test.

You said it started ok after the new rings, correct? So we can rule out a tight ring end gap.

If there's not excess gas in the cylinders, everything is pointing to amps.

Yeah, thats My guess also, but i ruled out battery issues when i jumped the starter with the battery Charger and it did the same thing, and usually we use that battery Charger to start every other bike without any trouble.
How can i use the battery tester to se how many amps is the starter drawing?

 

[Spockster]

Yeah, thats My guess also, but i ruled out battery issues when i jumped the starter with the battery Charger and it did the same thing, and usually we use that battery Charger to start every other bike without any trouble.
How can i use the battery tester to se how many amps is the starter drawing?

It has to be a load tester, a simple volt/ohm meter won't do it.

If a battery is too weak, a boost charger can't do it on its own. The battery has to have a certain level of amperage.

 

[JonathanP]

It has to be a load tester, a simple volt/ohm meter won't do it.

If a battery is too weak, a boost charger can't do it on its own. The battery has to have a certain level of amperage.

The battery Charger is an 30 years plus tungar that gives 20-25 amps, we used it to start bikes without battery, so it's odd that it doesn't do it on this one.
Yeah i have a load tester, but i haven't used it for.that matter thats why i am asking how

 

[Spockster]

The battery Charger is an 30 years plus tungar that gives 20-25 amps, we used it to start bikes without battery, so it's odd that it doesn't do it on this one.
Yeah i have a load tester, but i haven't used it for.that matter thats why i am asking how

Obviously I haven't seen your tester, but usually you just connect it then push and hold the test button for about 4-5 seconds while watching the the needle. If it's an electronic tester it will just show good or bad. There may be some settings that need adjusted first.

I've never seen a boost charger that could start something without a battery, mine is 100 amps and can't do it.

 

[JonathanP]

Obviously I haven't seen your tester, but usually you just connect it then push and hold the test button for about 4-5 seconds while watching the the needle. If it's an electronic tester it will just show good or bad. There may be some settings that need adjusted first.

I've never seen a boost charger that could start something without a battery, mine is 100 amps and can't do it.

Nevermind, i rechecked the starter and its grounded, i'm taking it to a specialized shop by now

 

[Spockster]

Nevermind, i rechecked the starter and its grounded, i'm taking it to a specialized shop by now

I'm not sure what's going on, but if it's bolted to the engine, it should be grounded.

 

[JonathanP]

The s

I'm not sure what's going on, but if it's bolted to the engine, it should be grounded.

The starter was drawing 120 amps, and i tested the cable of the starter to ground and it had continuity, so i disconected it from the starter and tested it again and it didnt showed continuity this time, so.i tested the positive from the starter to ground, and it showed continuity, i took it to an electrical shop that specializes i'm starters engines, so let's see what they Say about it, cuz from everything You've said and what i've seen, the problem has to be on the starter, i already did a load test like You suggested (My tester is one of those with the needle and the pushbotton btw) and it was good, and even tested the battery on a vulcan 1500 that i have as well, and it worked as spected, so it has to be the starter for sure

 

[Spockster]

The s
The starter was drawing 120 amps, and i tested the cable of the starter to ground and it had continuity, so i disconected it from the starter and tested it again and it didnt showed continuity this time, so.i tested the positive from the starter to ground, and it showed continuity, i took it to an electrical shop that specializes i'm starters engines, so let's see what they Say about it, cuz from everything You've said and what i've seen, the problem has to be on the starter, i already did a load test like You suggested (My tester is one of those with the needle and the pushbotton btw) and it was good, and even tested the battery on a vulcan 1500 that i have as well, and it worked as spected, so it has to be the starter for sure

The stud for the positive cable on the starter is supposed to be insulated from contacting the starter body (ground). So it's possible that insulation isn't right.

120 amp draw is about normal, but the extra amps must be going to the short (positive terminal and starter body).

Sounds like the starter is probably ok, just the terminal lug needs insulated.

 

[JonathanP]

The stud for the positive cable on the starter is supposed to be insulated from contacting the starter body (ground). So it's possible that insulation isn't right.

120 amp draw is about normal, but the extra amps must be going to the short (positive terminal and starter body).

Sounds like the starter is probably ok, just the terminal lug needs insulated.

Hopefully you're right, i'll come back with an update once i know what's going on with the starter, meanwhile, thank you so much for your help

 

[Spockster]

Hopefully you're right, i'll come back with an update once i know what's going on with the starter, meanwhile, thank you so much for your help

You're welcome, keep us posted.