Hunting between 4000 - 6000 rpm

[Dan Filetti]

Thanks for all the help, looks like it was a voltage thing after all, when the lights are on she hunts way more than when the lights are turned off, read about putting the relay into the curcuit so will be doing it this weekend and seeing if that solves it, will keep you posted, Once again thanks for all the input.

Keep the rubber side down

Uh, how do you turn the lights off without dissconnecting them?  Do you mean high-beams?

Just curious.

Dan

[Pat Conlon]

Relays are good. Do both the light relay and coil relay...getting full voltage works wonders for lumens and spark.
However, I'm unconvinced that low voltage from the oem wiring harness, is the root cause of your symptoms.
Something else is going on...

Thanks for all the help, looks like it was a voltage thing after all, when the lights are on she hunts way more than when the lights are turned off, read about putting the relay into the curcuit so will be doing it this weekend and seeing if that solves it, will keep you posted, Once again thanks for all the input.

Keep the rubber side down

[Pat Conlon]

Pull the fuse.

Thanks for all the help, looks like it was a voltage thing after all, when the lights are on she hunts way more than when the lights are turned off, read about putting the relay into the curcuit so will be doing it this weekend and seeing if that solves it, will keep you posted, Once again thanks for all the input.

Keep the rubber side down

Uh, how do you turn the lights off without dissconnecting them?  Do you mean high-beams?

Just curious.

Dan

[Dan Filetti]

Is this what you did, pull the fuse?

Like Pat, I'm dubious that this is the root cause of your issue.

Dan

[rktmanfj]

Is this what you did, pull the fuse?

Like Pat, I'm dubious that this is the root cause of your issue.

Dan

Unless the light circuit has a short in it...

Randy T
Indy

[Pat Conlon]

How would this be the case Randy?  The light circuit is a different circuit than the coil/ignition circuit...

Unless the light circuit has a short in it...

Randy T
Indy

[rktmanfj]

How would this be the case Randy?  The light circuit is a different circuit than the coil/ignition circuit...

Unless the light circuit has a short in it...

Randy T
Indy

Damned top posters...     

If he has a short in the light circuit (not necessarily to ground), it could cause all sorts of weirdness, and not pull enough current to smoke the fuse, especially if a DPO put the wrong fuse in it.

If it truly does change when the light circuit is hot, I'd at least consider isolating the lights and trace them.

Randy T
Indy

[andyb]

Just an offhanded, idle question.  How old's the battery, and what odds on the r/r feeding it a pinch aggressively?  It's happened once or twice before on the FJ, I understand....

[rktmanfj]

Just an offhanded, idle question.  How old's the battery, and what odds on the r/r feeding it a pinch aggressively?  It's happened once or twice before on the FJ, I understand....

I guess anything is possible, but I don't see where overvoltage to the coils is going to do anything but throw a fatter spark at the other end, and if the battery starts the bike okay, don't know what the problem could be there.

But if the light circuit really is causing a problem when it's energized, then tracing that would be my first step.

Randy T
Indy

[andyb]

I'm thinking more to the extent of torching a "reasonably good" battery and giving problems if the overvoltage situation is transient, i.e., when the r/r or other portions of the generation circuit are too hot.  If nothing else, on nearly any mysterious electrically related fault, a new, known good battery is a reasonably easy troubleshooting step, and a good foundation to build from for further troubleshooting.

[Dan Filetti]

I'll preface this by saying I'm not an expert, and am willing to be educated.  However, I will say that the reasoning for my doubt that "hunting between 4-6K RPM" is a spark issues, is rooted in the firm belief that a spark plug either sparks and lights the gas, or it does not.  

This idea that a 'fatter spark' being important has always annoyed me.  For the same reason, I never buy expensive, fancy, multi-tipped, titanium spark plugs I also think that an awful lot of time and energy goes into this, yet it may only be important for the folks that are dealing in that last .05% of the performance tuning -not even certain there.

So, the spark is either there or it's not, the cylinder is either firing or it's not, and, it seems to me, the plugs should show this.  Read the plugs: is there any indication that any/ all of them are rich/ carbonized?  If so, you may have an issue where you need to look at whether/ if you have spark issues.  Note: these could just as easily (more likely in my mind given the symptoms) be a carburetion issue.

I know a weak battery can cause wonky behavior, and that may be worth doing prophylactically if it's older, but "hunting between 4-6K RPM"  just 'feels' like a fueling issue.  All that being said, my opinion, and $1.75 will buy you a cup of coffee at Starbucks.

I'm still curious whether you actually pulled the headlight fuse to test this.  Seems an odd/ random test if so.  What made you consider this?

Dan

[rktmanfj]

I'm thinking more to the extent of torching a "reasonably good" battery and giving problems if the overvoltage situation is transient, i.e., when the r/r or other portions of the generation circuit are too hot.  If nothing else, on nearly any mysterious electrically related fault, a new, known good battery is a reasonably easy troubleshooting step, and a good foundation to build from for further troubleshooting.

True, but IME, if the battery voltages (with and without load) are nominal and constant, it already is a known quantity, IMO.

Overvoltage has not been mentioned here as a symptom here, BTW, though it is an FJ, I guess it can be assumed.

Randy T
Indy

[fugly]

Hi, Guys

Just a reply to some of the comments made regarding my questions, Firtsly it is easy to turn the light off I use the light switch on the right hand handlebar controls it has three settings off/ park and on. If I am riding and turn the lights off she runs a lot smoother as soon as I turn th elight switch to on she starts to hunt. We have checked for bad connection or earthing did not see anything. we have tested all possible voltage points battery etc and all is OK, she starts fine even if you leave her standing for a week or so, The battery is only a year old pushes 13,6 Volt, we are doing the relay thing over this weekend and will take her for a ride and give feed back. Thanks for all the interesting posts.