Misfiring - No power (Help needed)

Hello VFR gurus,

I am having a problem with my VFR 800A5 and your help will be much appreciated.

The bike runned perfectly and all of a sudden while running at mid range had a misfiring, something like a loss of power momentarily.
Then I rode the bike for about 60 Km without any problem. After that and while riding the loss of power was dramatic. Misfiring was continuous, the bike could hold the proper rpm in idle and sometimes shuts off.

I had to ride the bike like this for about 50-60Km at 60-100Km speed to get back home. When I finally stopped the exhausts and the catalytic converter were hot red!
Just to mention I have a plastic hugger that melted.
Engine temperature never exceeded 76 celsius degrees.

Any thoughts about the problem?

Any thoughts about the damage I have done from riding in these conditions?

You may have a bad spark plug, coil, or wire to the plug. The misfiring may be due to raw gas being exhausted into the exhaust system from the non-working cylinder and igniting there.

Check the easy stuff first like the plugs. If one has failed, it should be wet and black with soot.

.... When I finally stopped the exhausts and the catalytic converter were hot red!


Any thoughts about the damage I have done from riding in these conditions?

Probably picking up heat off the soon to be dead R/R. :biggrin:

Seriously, run the diagnostic routine on it with a volt meter. If you don't have the manual, I'm sure you can find the procedure and specs here or online.

Water in your fuel will cause erratic running and as was said before unburned fuel left over can cause the glowing exhaust especially if you have a cat. and I agree, change the plugs they are cheap. good luck

First off download the Service manual if you don't already have one here:
http://www.vfrdiscus...service-manual/

Then check the ECU(computer) for error codes, it could lead to right to the issue.

As mentioned after checking the codes, check the plugs. The coil is a Coil on Plug type so the only wires going to them are two small trigger wires. The problem cyl with show on the plugs for sure!

BR

Motorcycle troubleshooting is a form of problem solving... It is a
logical search for the source of a problem so that it can be solved...
it ain't about jumping to 10 conclusions at once... always eliminate
the battery first... because you find that 90% of the time it proves
to be the weakest link of your bike... and so much depends on correct
voltage that it's pays to have your battery tended to a charger at all
times...

Start with the battery for it's the weakest link in the whole system... To
determine the condition of an Maintenance Free battery give it a
refreshing charge... wait 30 minutes... measure terminal voltage...

12.8 or higher is a good battery...
12.0 to 12.8 is a insufficient charge... recharge...
12.0 or lower... battery unserviceable...

Water in your fuel will cause erratic running and as was said before unburned fuel left over can cause the glowing exhaust especially if you have a cat. and I agree, change the plugs they are cheap. good luck

I got the tank completely empty and tried already. No issue with the fuel.

12.8 or higher is a good battery...
12.0 to 12.8 is a insufficient charge... recharge...
12.0 or lower... battery unserviceable...

No issue with the battery. Battery is new and working fine. Also the charging system is ok. Measurement at idle is 14.6 - 14,8 volts. Stator and R\R OEM brand new.

Have you verifired the connections to the coils and the coild are good?

Worked on my friends car and a coil was causing the car to mis-fire. Eventually caused the brain to fry. :angry:

Just try to voltage test per manual and rule it out. You could also swap coils around to see it the problem then goes to the other cylinder. Just make sure you keep good notes.

Is the bike stock or does it have a power commander on it?

Rollin

Is the bike stock or does it have a power commander on it?

Rollin

Completely stock.

Not sure if they make em for motorcycles, (I am a car mechanic) but you can go to autozone and get one of them cheapo spark testers to connect inbetween your spark plug and coil wife / coil to see if they are firing. If they are then you at least narrow that part down. Is it overheating? Head gasket maybe?

EDIT: just reread the red hot exhaust.. kind of rule out Head gasket as the gas is heating up your exhaust. Sounds like you have a dead cylinder.

[image: View Post]Infidel, on 27 January 2011 - 04:28 PM, said:

Not sure if they make em for motorcycles, (I am a car mechanic) but you can go to autozone and get one of them cheapo spark testers to connect inbetween your spark plug and coil wife / coil to see if they are firing. If they are then you at least narrow that part down. Is it overheating? Head gasket maybe?

EDIT: just reread the red hot exhaust.. kind of rule out Head gasket as the gas is heating up your exhaust. Sounds like you have a dead cylinder.


Are you talking about the inductive ones? I don't think these work for coil-over-plug wires like a VFR has.

6thgen has direct fire coils on top of plugs, theres no coil wire

[image: View Post]RobertoDiavolo, on 26 January 2011 - 03:10 PM, said:

The bike runned perfectly and all of a sudden while running at mid range had a misfiring, something like a loss of power momentarily.
Then I rode the bike for about 60 Km without any problem. After that and while riding the loss of power was dramatic. Misfiring was continuous, the bike could hold the proper rpm in idle and sometimes shuts off.

Your description sounds like exactly the same symptoms I had on my '01 a while back. I'd be riding along, and it was like someone had flicked the kill switch momentarily. I never found exactly what caused it, but after doing lots and lots of forum browsing (particularly the UK VFR forum, as I found nothing the same on VFRD), I decided it had to be related to the ECU. I disconnected the ECU, cleaned all the pins, checked them and the wires to them very carefully. However, I wasn't totally sure that was the fault, so I rewired the ground cluster, removing the plug where all the green wires congregated, and crimped/soldered them together in a big bunch, with some wires from there direct to the frame. For good measure, I also made sure there was a decent separate ground source for the ECU itself, by finding the ground wire there and running a wire from there to the frame. Then I fitted a new battery, as the problem was still there.
Dunno which thing fixed the problem, but it's been fine for the last year or so.
Interestingly (or perhaps not...), I found nothing worng with any of the things I checked: no obvious looseness in the connections, no corrosion, nada. And each of the things I tried didn't seem to make much of an immediate difference on its own.

The best thing is the rate of crashing, dying, bursting into flames, exploding and dying all over again (I *HATES* that) :pissed: has dropped to approximately zero since then. :fing02:

Must be time for something else to "pack a sad", as they say here in Noo Zilund... :blink:

[image: View Post]Ryanme17, on 27 January 2011 - 05:09 PM, said:

[image: View Post]Infidel, on 27 January 2011 - 04:28 PM, said:

Not sure if they make em for motorcycles, (I am a car mechanic) but you can go to autozone and get one of them cheapo spark testers to connect inbetween your spark plug and coil wife / coil to see if they are firing. If they are then you at least narrow that part down. Is it overheating? Head gasket maybe?

EDIT: just reread the red hot exhaust.. kind of rule out Head gasket as the gas is heating up your exhaust. Sounds like you have a dead cylinder.


Are you talking about the inductive ones? I don't think these work for coil-over-plug wires like a VFR has.


Yeah I was.. I got one off the Snapon truck that works wonders on Cars. I hate part swapping so I tend to buy any and every tool I can get my hands on that will troubleshoot. :D

Come on folks, this sounds exactly like a cylinder has just dropped spark.

Give the guy some time to check his ECU error codes and if any of his spark plugs are wet before throwing five million possible causes at him, eh?

[image: View Post]kaldek, on 27 January 2011 - 08:13 PM, said:

Come on folks, this sounds exactly like a cylinder has just dropped spark.

Give the guy some time to check his ECU error codes and if any of his spark plugs are wet before throwing five million possible causes at him, eh?


He was suggested that already. Should have been the first thing he checked, eh?

Having said that... any luck yet on your problem?