2015 VFR800DLX No Start…

[SgtMarbles]

Good afternoon,

 

A few weeks ago I was riding my 2015 VFR800DLX back home from a long day. I was sitting at an intersection when the bike died. The bike did not even engage the starter when I attempted to start it back up, just clicking. So I attempted to bump start but with no success. 
 

I checked all the fuses including the 20 and 30 AMP fuses on the starter relay and all are intact. I put in a fresh starter relay last season, and I put in a new fully charged battery once I bought the bike home and started to try to diagnose it.
 

When the ignition is turned on the fuel pump does prime. Once I click the starter the dash and lights turn off and the bike just clicks, no crank at all. The battery drops from 12.7V to 6.8V when I engage the start button, the fuel pump does re-prime itself almost every time I let off starting button.

 

I went through all the gears and with the clutch in and spinning the tire by hand, I can hear the cylinders moving which means it is not a mechanical issue.

 

How would you guys recommend proceeding? I suspect it may be the regulator rectifier or stator but that still would not explain why the bike would not be able to bump start. Could it be a fuel delivery issue and that is why the starter motor won’t crank? 
 

Either way, the bike won’t let me bump start so I am just not entirely sure what the issue could be.

 

Cheers! 

[Presson]

If you had a Reg/Rec problem on your 8 Gen you would be the first to do so. As the late Grum used to point out those components were where Honda had finally made the improvement needed to prevent failures.

On bump starting, my experience is that doing that with an 8 Gen is a 2 person job (or a very steep hill).

 

Have you got the manual from the download section? I've put the link to the latest version of the manual below. Page 6-3 gives you the troubleshooting flow. You say you've tried a new battery, but the original symptoms - especially dying at idle - do sound like they could be due to a duff one; simple voltage checking won't tell you if the new battery can produce the cranking current - an auto store may be able to check for you. I recently purchased a new battery but had to exchange it 2 days later because it was duff, so it does happen.

 

Once you've confirmed the kill switch is set to run and you're dealing with a good battery, but the problem  persists, it sounds like you need to check the starter motor is working by applying voltage directly using a thick cable. That will help indicate if your starter is faulty, there's a cable fault on the feed to the starter, or the relay/solenoid needs investigating.

 

 

 

[SgtMarbles]

9 hours ago, Presson said:

If you had a Reg/Rec problem on your 8 Gen you would be the first to do so. As the late Grum used to point out those components were where Honda had finally made the improvement needed to prevent failures.

On bump starting, my experience is that doing that with an 8 Gen is a 2 person job (or a very steep hill).

 

Have you got the manual from the download section? I've put the link to the latest version of the manual below. Page 6-3 gives you the troubleshooting flow. You say you've tried a new battery, but the original symptoms - especially dying at idle - do sound like they could be due to a duff one; simple voltage checking won't tell you if the new battery can produce the cranking current - an auto store may be able to check for you. I recently purchased a new battery but had to exchange it 2 days later because it was duff, so it does happen.

 

Once you've confirmed the kill switch is set to run and you're dealing with a good battery, but the problem  persists, it sounds like you need to check the starter motor is working by applying voltage directly using a thick cable. That will help indicate if your starter is faulty, there's a cable fault on the feed to the starter, or the relay/solenoid needs investigating.

 

 

 

I put the battery on the trickle charger last night and got the same result, I will be checking the starter motor later today.

One other thing I remembered was the horn sounding rather “derpy” and off key the day before the bike died on me. If the RR is bad it would explain why it sounded like it did. Just another symptom I am noting…
 

Cheers!

[Captain 80s]

Just because the trickle charger (or a multi-meter) might report "charged", it doesn't mean the battery can withstand a load.  Even if the battery is new, it may have been damaged from being ran down due to a failing charging system or just a bad battery from the get-go.  It happens.

 

If you have a car handy, run some jumper cables to the bike without the car running and see what happens just for giggles.

[Presson]

If you look in the manual, you can easily check the reg/rec. At 5000rpm you should be seeing 14.5v at the battery. Clearly you need to get it started first and Captain 80s has explained how to do that simply.

 

As I said before, the 8 Gen is not known for the reg/ rec problems of earlier generations. I'd do the checks before assuming the worst.

[SgtMarbles]

On 9/25/2025 at 12:08 PM, Captain 80s said:

Just because the trickle charger (or a multi-meter) might report "charged", it doesn't mean the battery can withstand a load.  Even if the battery is new, it may have been damaged from being ran down due to a failing charging system or just a bad battery from the get-go.  It happens.

 

If you have a car handy, run some jumper cables to the bike without the car running and see what happens just for giggles.

I hooked up some jumper cables to the car and bike, still the same result. No start, no crank, just a click.

The bike died while it was running so im just trying to grasp why the starter motor would have any confliction? I also don’t understand why the bike wouldn’t bump start, I have done it countless times before.

 

 

[Captain 80s]

There is a chance that the battery is so damaged that it is impeding a good battery from making a difference.  I've had that happen multiple times over the last few decades.

 

If it was me, I would eliminate the bike battery and jump right to the battery cables (carefully) to absolutely take that possibility out.

 

Then I would apply voltage directly to the starter, or the starter side of the relay to see if the starter is operational.

 

The click is likely telling you that the relay is working.

 

How does your oil level look? 

 

Maybe remove your plugs and see if you are hydro locked for some reason.

 

Grasping, but these are all still possibilities.

[SgtMarbles]

4 hours ago, Captain 80s said:

There is a chance that the battery is so damaged that it is impeding a good battery from making a difference.  I've had that happen multiple times over the last few decades.

 

If it was me, I would eliminate the bike battery and jump right to the battery cables (carefully) to absolutely take that possibility out.

 

Then I would apply voltage directly to the starter, or the starter side of the relay to see if the starter is operational.

 

The click is likely telling you that the relay is working.

 

How does your oil level look? 

 

Maybe remove your plugs and see if you are hydro locked for some reason.

 

Grasping, but these are all still possibilities.

Jumped the cables with the same result.
 

Oil level is at the same level the service manual instructs. The motor is not hydro locked.

 

I pulled out the regulator rectifier and found that it is not stopping current from the wrong direction. It also will not allow me to forward bias the diodes. 
 

I will still be inspecting the starter motor itself. 

 

Cheers! 

[Presson]

You switch on, the fuel pump primes, press start and you get a click but no start. This sounds like a battery or  starter fault or a fault on one of the switches ( clutch/ side stand) or one of the diodes ( clutch/ neutral) or on a relay. I suppose you could have a problem on the charging circuit but as Terry pointed out, that is not going to prevent the engine starting and running if the battery is good.

 

I would:

1. Check DTC codes to eliminate confusion from problems there.

2. Do as Captain 80s suggested by trying the starter from a car battery but eliminating the bike battery. If the starter turns you'll know it's a bad battery problem. I wasn't absolutely clear that you've done this already.

3. If no starter function, try 2 with clutch pulled in and side stand up - worth giving the side stand switch a good clean. If you get a get a starter motor function at this point you can be sure it's a switch problem.

3. If no solution, follow the diagnostic procedure for the starter system on page 6-3 of the manual that will work through every part of the system down to the switches and diodes. You'll need a good battery.

4. Do the checks on the charging system from page 19-4 of the manual.

 

Good luck

 

 

[Presson]

I knew it was there somewhere. The 8 Gen MOSFET reg/rec has a self test function for the complete charging system at each switch on but the codes are not stored so you have to read them off immediately. Page 19-7 of the manual refers.

[SgtMarbles]

On 9/26/2025 at 4:20 PM, Captain 80s said:

There is a chance that the battery is so damaged that it is impeding a good battery from making a difference.  I've had that happen multiple times over the last few decades.

 

If it was me, I would eliminate the bike battery and jump right to the battery cables (carefully) to absolutely take that possibility out.

 

Then I would apply voltage directly to the starter, or the starter side of the relay to see if the starter is operational.

 

The click is likely telling you that the relay is working.

 

How does your oil level look? 

 

Maybe remove your plugs and see if you are hydro locked for some reason.

 

Grasping, but these are all still possibilities.

Alright,

 

I removed the starter and checked it. The starter is in good health.

 

I checked the side stand switch, however I was a little confused because when I attempted to check the pins they were reading 0 in the diode mode. Side stand up, side stand down, it read zero both ways.

 

I will check the clutch and neutral switch later this evening.

I decided to drain the oil in the bike and inspect it to see if there might be anything out of the ordinary. No metal flakes or coolant, so I can rule out the engine for now. 
 

Making some progress so far! 

[Presson]

Side stand switch. Test in ohms mode at the black connector under the LHS middle cowl. Zero continuity when down, continuity when retracted (up).

[SgtMarbles]

7 minutes ago, Presson said:

Side stand switch. Test in ohms mode at the black connector under the LHS middle cowl. Zero continuity when down, continuity when retracted (up).

I checked using ohms this time, still no continuity… 

[Presson]

Well that's a problem. Zero continuity means the system thinks the stand is down. It should not stop a start but will definitely kill the engine when you put it into gear. 

 

You say the starter motor is okay. Have you been able to get it to turn the engine over even if jumped to the battery leads from a car battery without the bike battery in the circuit?

[SgtMarbles]

3 minutes ago, Presson said:

Well that's a problem. Zero continuity means the system thinks the stand is down. It should not stop a start but will definitely kill the engine when you put it into gear. 

 

You say the starter motor is okay. Have you been able to get it to turn the engine over even if jumped to the battery leads from a car battery without the bike battery in the circuit?

I haven’t been able to attempt to get the starter motor to turn over on the bike, I will have to pick up smaller battery leads for that.
 

 

I am going to check the clutch and neutral switch and see if there is any sort of issue in that realm. 

 

 

 

[Presson]

Possibly a silly question, but you're sure the multimeter battery is ok? Switched to ohms it should read 1 with probes apart and 0 with probes crossed ( connected together).

 

Pretty sure the neutral switch will be okay if the green N symbol lights in the dash with the gears in neutral 

[SgtMarbles]

12 minutes ago, Presson said:

Possibly a silly question, but you're sure the multimeter battery is ok? Switched to ohms it should read 1 with probes apart and 0 with probes crossed ( connected together).

 

Pretty sure the neutral switch will be okay if the green N symbol lights in the dash with the gears in neutral 

The multimeter is fine, it has an auto setting so it only displays 0.00 unless it detects a connection or current. 

[airwalk]

I know you’ve checked the associated fuses but why not replace them, it wouldn’t be impossible for a fuse to look/test ok but still not pass power, even though the meter says otherwise. I’ve seen it happen more than once over the years..

[SgtMarbles]

18 hours ago, airwalk said:

I know you’ve checked the associated fuses but why not replace them, it wouldn’t be impossible for a fuse to look/test ok but still not pass power, even though the meter says otherwise. I’ve seen it happen more than once over the years..

I will more than likely do that tomorrow.
 

However the part that isn’t making sense to me is the matter that the bike cannot be bump started. When I engage the start button, the starter itself does not even make a noise.
 

This means that voltage is not getting to the starter itself. But if that is the case, why am I not able to bump start it? The kill switch is fine, even if the clutch or side stand switch were bad the bike should still start in neutral if the neutral switch is fine. The neutral indicator is displayed so I wouldn’t see it as an issue, but I will still test it just in case.

 

The only weird thing to note is the rear wheel when in 6th gear with the clutch out, it will not turn. Like, there is the normal front-back play, but the tire itself will not spin forcefully by hand…

 

I am debating if I should remove the crank case cover and try to see if I can turn the motor, but all these clues are pushing me towards it being an electrical issue.

[Presson]

For god's sake mate. Put a new and good  battery in the thing. Everything you described points that way but you seem to be looking for deeper problems.

 

If the battery is completely knackered you won't be able to bump start it.

 

A charger saying the battery is full is simply saying it's got top voltage. Not ability to current draw.

 

You've said a number of times about bump starting. Is this a clue about a problem coming on. I've pointed you in the direction of the diagnostic tree. 

 

I'm done

[SgtMarbles]

2 minutes ago, Presson said:

For god's sake mate. Put a new and good  battery in the thing. Everything you described points that way but you seem to be looking for deeper problems.

 

If the battery is completely knackered you won't be able to bump start it.

 

A charger saying the battery is full is simply saying it's got top voltage. Not ability to current draw.

 

You've said a number of times about bump starting. Is this a clue about a problem coming on. I've pointed you in the direction of the diagnostic tree. 

 

I'm done

The thing is, I did put a fresh, out of the box, new battery in it as my first step to diagnosing this issue.
 

After the bike died I ordered a new battery and switched it out with the exact same result. The voltage drop is 5 volts, it goes from 12.7 - 6.8

 

With the old battery before I replaced it as per your instructions it was 12.1 - 5.8

 

I can try and swap yet another battery, but I do not think in any way that this is the source of said issue. 

I appreciate the input I have received from all of you. 

[Presson]

Ok, despite what I said:

 

Your starter motor is fine - checked off the bike or via a jump to the +ve side.

You have a new or good battery.

You get normal indications when you switch on

You get a click but no engine rotation when you press the starter.

The bike is in neutral and the side stand is down 

 

The problem has to be between the battery and the starter motor surely?

 

Reg/rec stuff is irrelevant if the battery is good.

 

Check replace fuses.

Check starter relay and wiring to starter motor.

Follow the starter diagnostic tree from the manual 

 

 

 

 

[Captain 80s]

30 minutes ago, Presson said:

Your starter motor is fine - checked off the bike or via a jump to the +ve side.

 

Did I miss the post where it said this was done?

[Presson]

On 9/28/2025 at 8:34 PM, SgtMarbles said:

Alright,

 

I removed the starter and checked it. The starter is in good health.

 

I checked the side stand switch, however I was a little confused because when I attempted to check the pins they were reading 0 in the diode mode. Side stand up, side stand down, it read zero both ways.

 

I will check the clutch and neutral switch later this evening.

I decided to drain the oil in the bike and inspect it to see if there might be anything out of the ordinary. No metal flakes or coolant, so I can rule out the engine for now. 
 

Making some progress so far! 

Here 

[Crusty1]

On 9/29/2025 at 3:13 PM, SgtMarbles said:

After the bike died I ordered a new battery and switched it out with the exact same result. The voltage drop is 5 volts, it goes from 12.7 - 6.8

The battery should never drop below 10v when cranking.  The electronics need at least that to work. That may be why it wont bump start.  Put it in neutral when cranking and that will eliminate the side stand and clutch switches. It should crank in neutral regardless of the side stand or clutch switch positions.  Be sure you are testing at the actual battery posts and not the connectors bolted to the terminals. If you are only getting 6.8V at the starter that is a big problem usually caused by a poor connection at the battery or a failing starter relay.