Vfr750 Cutting Out

Morning all

I went out for a nice run yesterday, got some nice high speed runs on a private stretch of road.  Everything was hunky dory.

Just before this, I installed a Delkevic stubby exhaust, sealed nicely, no blows etc - sounds great and seems to have freed up a flat spot at 6krpm.

Anyway.  I started the bike this morning, choke on full as it was freezing.  It burped into life, instead of jumping to around 2000-2500rpm is sat just around 1500.  If I gave it a bit of throttle it didn't do much, just seemed to rev a tiny bit, as though the throttle cable was really slack or something, best way I can describe it!

I let it sit for a few minutes and it eventually went a bit higher up the revs but not massively.  I turned the choke off and it idled at around 1000rpm (I have it set to 1200), again the throttle didn't seem to do much.

To make things worse, traffic was awful due to an accident and the bike cut out three times.  Once when I was sat at idle and I gave it a bit of throttle to see if it was still lagging (which it wasn't) but as soon as the revs came down it cut out.  Fired up fine and carried on.  It then cut out again while in gear, idling, with the clutch pulled in.  Again it fired up fine.  It then did exactly the same thing a few metres down the road.

I got to the indoor carpark and parked up.  Gave it a blip and a bit more of a handful and it seemed ok, didn't cut out.  I don't know if it's just me but the exhaust sounds a little different to yesterday, not quite as smooth.

I'm finishing work at 4pm so I'll see how it fires up.

I'm thinking the following though:

reg/rec is duff?  If I buy a voltmeter, how do I actually test the voltage, by simply putting the voltmeter against one of the battery terminals?  I believe it should be between 12-15v at idle?  Correct me if I'm wrong, some steps to follow would be appreciated. If I put the bike in neutral and turn on the headlights (normal beam) and give it a rev, they should go a bit brighter, if they don't, is that a dead set reg/rec issue?

carb issue?  I know the bike was sat for a year or two before I bought it, the guy I bought it off had it serviced and it's always fired up fine (although it's required a smidge of throttle on occasion).  So maybe they need a clean.

Is there anything else I should check?  I'm not very mechanically minded with electrics and what not.  I'm not shy though and will give it a go.

http://www.vfrdiscussion.com/forum/index.php/topic/78599-troubleshooting-1995/?p=957305 

Thanks Dutchy, did have a read of that :)

Some questions about it: 

The Drill
Go through all your connectors for burnt leads, dig deep. Crispy wires? Not good. The stator connector is the number one burn it up connector on the bike. - Your gonna have to fix that!  Even if they look good, time to GENTLY pinch all female connectors to ensure a tight fit.

Female connectors? I'm assuming this is anything that simply clips together?

Then---Go through this starting point quick list. You will need a multimeter too.

Steps: ---
- Recharge battery overnite - then to take it to Autozone or similar to load test. -- Good? Bad? – An iffy battery can fake you out and act like a bad R/R. Buy new if needed.

- With good battery fire it up, warm up for a minute or two.

I don't have a charger nor the time to do this due to working very early mornings so wiring it all back up is too much effort (just take this for what it is, I literally have no time), wouldn't doing this after a ride be enough?

These are R/R quick checks---
--- With voltmeter at battery posts get voltages -- idle volts? 5000 rpm volts? What’s the numbers? Should be in 13ish min idle and in 14s at revs. (if in the 12s at idle, check at about 1900rpms instead. Its not unusual for the system to be in discharge at idle. )

13-13.75 at idle on a warm bike

9.5-11 with the lights on at idle

9-11 with the lights off but the fan turned on at idle

12.8 with the bike turned off

10-11 at around 5krpm

- Check stator - These tests are done checking the connector that goes to the stator. (Engine off)
1. Pull connector apart. Set meter to resistance. Check pin to pin, 3 yellow wires, A to B, B to C, C to A. What’s the numbers? 3 separate readings --Should be less than 1.0 ohms.

Isn't the stator under the engine casing?  Not doing this until the weekend, I need my bike for transport.  Seems like an epic effort but will do it if I have to.

- 2. Check continuity from each A,B,C pin to ground, -- -should be infinity - nada nothing. no continuity. -- 3 separate checks. (Connector still apart, engine off)

- 3. Crank it back up. Do another pin to pin thing, but set meter on AC volts. idle and 5000 rpms. What's da numbers? Should start 15 -20ish and climb 60ish and more. Again – 3 readings- (Again, connector apart) Repeat hot.

Do this on the stator with the bike turned on and idling?

Also, I bought a temperature laser gun.  Front down pipes are about 145-150 each, rear down pipes are about 200-210, the RR was around 20-21 (all in degrees celcius) so at least I know it's firing on all four.

Thanks Dutchy, did have a read of that :)

Some questions about it: 

The Drill
Go through all your connectors for burnt leads, dig deep. Crispy wires? Not good. The stator connector is the number one burn it up connector on the bike. - Your gonna have to fix that!  Even if they look good, time to GENTLY pinch all female connectors to ensure a tight fit.

Female connectors? I'm assuming this is anything that simply clips together?

Then---Go through this starting point quick list. You will need a multimeter too.

Steps: ---
- Recharge battery overnite - then to take it to Autozone or similar to load test. -- Good? Bad? – An iffy battery can fake you out and act like a bad R/R. Buy new if needed.

- With good battery fire it up, warm up for a minute or two.

I don't have a charger nor the time to do this due to working very early mornings so wiring it all back up is too much effort (just take this for what it is, I literally have no time), wouldn't doing this after a ride be enough?

These are R/R quick checks---
--- With voltmeter at battery posts get voltages -- idle volts? 5000 rpm volts? What’s the numbers? Should be in 13ish min idle and in 14s at revs. (if in the 12s at idle, check at about 1900rpms instead. Its not unusual for the system to be in discharge at idle. )

13-13.75 at idle on a warm bike

9.5-11 with the lights on at idle

9-11 with the lights off but the fan turned on at idle

12.8 with the bike turned off

10-11 at around 5krpm

- Check stator - These tests are done checking the connector that goes to the stator. (Engine off)
1. Pull connector apart. Set meter to resistance. Check pin to pin, 3 yellow wires, A to B, B to C, C to A. What’s the numbers? 3 separate readings --Should be less than 1.0 ohms.

Isn't the stator under the engine casing?  Not doing this until the weekend, I need my bike for transport.  Seems like an epic effort but will do it if I have to.

- 2. Check continuity from each A,B,C pin to ground, -- -should be infinity - nada nothing. no continuity. -- 3 separate checks. (Connector still apart, engine off)

- 3. Crank it back up. Do another pin to pin thing, but set meter on AC volts. idle and 5000 rpms. What's da numbers? Should start 15 -20ish and climb 60ish and more. Again – 3 readings- (Again, connector apart) Repeat hot.

Do this on the stator with the bike turned on and idling?

Also, I bought a temperature laser gun.  Front down pipes are about 145-150 each, rear down pipes are about 200-210, the RR was around 20-21 (all in degrees celcius) so at least I know it's firing on all four.

Female contacts: Yes, like in the picture of the main reg/rec connector, below:

[image: 5P250-305K_1.jpg]

Good battery:  The battery is the heart of the VFR charging system, so until you KNOW you have a good battery (by testing it or replacing it), running the other tests is somewhat pointless.  Could you swap the battery from your other bike?

Voltages:  Not good at all.  But it could just be a duff battery.

Ciao,

pm sent!!  :beer:   :fing02:

Thanks Dutchy, did have a read of that :)

Some questions about it: 

The Drill
Go through all your connectors for burnt leads, dig deep. Crispy wires? Not good. The stator connector is the number one burn it up connector on the bike. - Your gonna have to fix that!  Even if they look good, time to GENTLY pinch all female connectors to ensure a tight fit.

Female connectors? I'm assuming this is anything that simply clips together?

Then---Go through this starting point quick list. You will need a multimeter too.

Steps: ---
- Recharge battery overnite - then to take it to Autozone or similar to load test. -- Good? Bad? – An iffy battery can fake you out and act like a bad R/R. Buy new if needed.

- With good battery fire it up, warm up for a minute or two.

I don't have a charger nor the time to do this due to working very early mornings so wiring it all back up is too much effort (just take this for what it is, I literally have no time), wouldn't doing this after a ride be enough?

These are R/R quick checks---
--- With voltmeter at battery posts get voltages -- idle volts? 5000 rpm volts? What’s the numbers? Should be in 13ish min idle and in 14s at revs. (if in the 12s at idle, check at about 1900rpms instead. Its not unusual for the system to be in discharge at idle. )

13-13.75 at idle on a warm bike

9.5-11 with the lights on at idle

9-11 with the lights off but the fan turned on at idle

12.8 with the bike turned off

10-11 at around 5krpm

- Check stator - These tests are done checking the connector that goes to the stator. (Engine off)
1. Pull connector apart. Set meter to resistance. Check pin to pin, 3 yellow wires, A to B, B to C, C to A. What’s the numbers? 3 separate readings --Should be less than 1.0 ohms.

Isn't the stator under the engine casing?  Not doing this until the weekend, I need my bike for transport.  Seems like an epic effort but will do it if I have to.

- 2. Check continuity from each A,B,C pin to ground, -- -should be infinity - nada nothing. no continuity. -- 3 separate checks. (Connector still apart, engine off)

- 3. Crank it back up. Do another pin to pin thing, but set meter on AC volts. idle and 5000 rpms. What's da numbers? Should start 15 -20ish and climb 60ish and more. Again – 3 readings- (Again, connector apart) Repeat hot.

Do this on the stator with the bike turned on and idling?

Also, I bought a temperature laser gun.  Front down pipes are about 145-150 each, rear down pipes are about 200-210, the RR was around 20-21 (all in degrees celcius) so at least I know it's firing on all four.

Female contacts: Yes, like in the picture of the main reg/rec connector, below:

[image: 5P250-305K_1.jpg]

Good battery:  The battery is the heart of the VFR charging system, so until you KNOW you have a good battery (by testing it or replacing it), running the other tests is somewhat pointless.  Could you swap the battery from your other bike?

Voltages:  Not good at all.  But it could just be a duff battery.

Ciao,

Thanks buddy, My other bike's battery is dead as a dodo.  Don't suppose you have a charger I could borrow?  Also, watch this video for voltages and what not, might paint a better picture than I've written haha

[video: http://youtube.com/embed/7qhU4heMTfA?html5=1&fs=1]