Neutral light varying intensity with RPMs - could it indicate some potential problem?

[Norway]

Today I noticed that the neutral light on my 250R had a varying intensity with the engine speed / RPMs. Since I can't remember having seen this before (even though it might have happened), I am wondering if anyone has noticed this on their own, or other, 250Rs?
Could it be a sign of a weak battery or some other potential problem outside my own head? ;-)

[Triple Jim]

It depends on how it varies with speed. If it gets a little brighter when you go from idle to a little higher RPM, that's normal. If it continues to get brighter with further increase in RPM, that might indicate a failed regulator.

Measure the battery voltage at various engine speeds to see if it stays steady around 14-ish volts, except for a little drop at idle.

[Bob KellyIII]

it also may indicate that the idle is too low in RPM.... I think Kawasaki says 1500 RPM at idle and that is way, way too fast for my liking so I lowered mine to around 800 RPM..... these altenators only put out 12VDC at above 1200~1500 RPM so it may well indicate the battery is getting bad and the difference you are seeing is the difference between 12vdc and 14vdc and yes you can see that difference easily. But why guess ? put a volt meter on the battery, start it and see what it is doing ! above 2000 RPM you should see 13.5~14.0 Volts dc below that 12.5 or what ever your battery is putting out.( your voltage may veri a bit)
if you run the bike for about 30 minutes at road speeds and the battery isn't at at least 13.volts it's time for a new battery !
Motorcycle batteries have come a long way sense I was a Kid back then you could not find a battery that would last over a year...... now that is not the case but you can't expect them to last like a car battery ! 2 ~3 years in my experience is tops
....
Bob

[ducatiman]

IF testing reveals a faulty RR, I strongly recommend a genuine (only) Shindengen FH020 Mosfet. Incedibly reliable, long lasting, cool running.

[Bob KellyIII]

things that Kill regulators.... for a while back in the 1960's the regulator could be fried just by jumping the bike you know jumper cables correct polarity to a good car battery.... Not that is not so much the case you can do that and get away with it with no problem.... SHOCKS to the electrical are the biggest Killer
so if you Jump your bike do these things... make sure the key is off...
hook up the jumper cables and make darn sure the polarity is correct one Touch with the wrong polarity can fry the regulator.
once the jumper battery is hooked up you can start the bike like normal
if you hit the starter and nothing happens or you just get a real slow turning over stop turn the key off and then work on the electrical connection between the jumper battery and the bike you don't want to do that with the key on
once a good electrical connection is established the bike should start like ...normal ...... then leave the bike running and disconnect the jumper battery.....( positive first) if the bike dies like you turned off the key the voltage regulator is already fried.... and it needs replaced if it continues to run the voltage regulator is probably ok. and obviously just the battery needs replaced....
....
it's a good practice to remove the battery, charge it and then try starting if the bike has been sitting a long time 3~4 Months or longer.... if Sta-bul360
was put into the gasoline before hand the bike should start ... if you didn't put a fuel stabilizer in the gasoline the gasoline should be drained and the carb bowls drained as well....
you do NOT nessarally have to clean the carbs on a bike if a gas stablizer was used prior to storage ! just because it sat for some time does not mean the carbs will be crusty..... the gas stabilizer is a yearly thing on my bikes
I swear by it ! ....
be aware that you can fry a voltage regulator easily by Jumping the bike to start it.... that is why alot of guys won't jump a bike ! but if you do it correctly there is no problem
....
the biggest cause of voltage regulator failure is Shorts and shocks to the system.... they will not survive a intermittent connection very long in any part of the system.... a dirty headlight switch took out the regulator in my VT700 Honda one time.... and there was no other problems with the wiring
you could turn on the headlight and it not come on , hit a bump and it come on.... that intermittent connection is what took out the Voltage regulator
and it cost over $120.00 at the time.
tearing apart the switch and cleaning up the switch contacts cured the problem.

Bob.....

[ducatiman]

most common cause of RR failures...loose/dirty terminals, eventually culminating in totally burnt mid-connectors are quite common (and not limited to EX's)...frankly, are posted all over the I'net in model specific forums....check your mid-connectors guys! Better yet....eliminate them...rewire as necessary.

[Norway]

Originally Posted by Triple Jim

It depends on how it varies with speed. If it gets a little brighter when you go from idle to a little higher RPM, that's normal. If it continues to get brighter with further increase in RPM, that might indicate a failed regulator.

Measure the battery voltage at various engine speeds to see if it stays steady around 14-ish volts, except for a little drop at idle.

Not having to remove the seat, I connected to one of the wires (probably) connected to some rear light. Before starting the engine I read about 11.5 V. After starting it, it seemed to stabilize at around 12.8 V, when increasing the RPMs well above idle. Guess the positive / + voltage should be more or less similar for any rear bulb as at the battery (?).
Just tried it..
I had expected a higher voltage, more like 13-14 V...

[Bob KellyIII]

Pull the battery and charge it to full... and see if it holds it's charge ...if not the battery is toast.... it should read 12.5 fully charged and should hold that charge for weeks..... if you charge it up and it goes back down to 11.5vdc over a few days...the battery is on it's last leg and needs replaced.
.....
Bob.....

[Norway]

Originally Posted by Bob KellyIII

Pull the battery and charge it to full... and see if it holds it's charge ...if not the battery is toast.... it should read 12.5 fully charged and should hold that charge for weeks..... if you charge it up and it goes back down to 11.5vdc over a few days...the battery is on it's last leg and needs replaced.
.....
Bob.....

Thanks. I went out in the shed and this time I took the time to remove the seat and what was needed to access the battery directly. Now I measured 12.5 V on the battery, and about 13.7 V when the engine was running.
So, hopefully things are ok.

[Norway]

Originally Posted by ducatiman

most common cause of RR failures...loose/dirty terminals, eventually culminating in totally burnt mid-connectors are quite common (and not limited to EX's)...frankly, are posted all over the I'net in model specific forums....check your mid-connectors guys! Better yet....eliminate them...rewire as necessary.

Thanks for sharing your knowledge. Luckily, measurements indicate that the battery and charging system are working ok.

[Norway]

Originally Posted by Triple Jim

It depends on how it varies with speed. If it gets a little brighter when you go from idle to a little higher RPM, that's normal. If it continues to get brighter with further increase in RPM, that might indicate a failed regulator.

Measure the battery voltage at various engine speeds to see if it stays steady around 14-ish volts, except for a little drop at idle.

Thanks. It stayed around 13.7 V without high RPMs. Just measured it..

[Triple Jim]

Originally Posted by Norway

Thanks. It stayed around 13.7 V without high RPMs. Just measured it..

The point is that if the regulator is bad and you rev the engine a bit, like 3,000 rpm or so, the voltage could keep climbing higher. That would be bad, since it will make light bulbs and the battery fail.

[Norway]

Originally Posted by Triple Jim

The point is that if the regulator is bad and you rev the engine a bit, like 3,000 rpm or so, the voltage could keep climbing higher. That would be bad, since it will make light bulbs and the battery fail.

Thanks. I may check that. I revved the engine somewhat, without looking at the counter, but suspect that the voltage remained on the "safe side".

[Bob KellyIII]

Originally Posted by Triple Jim

The point is that if the regulator is bad and you rev the engine a bit, like 3,000 rpm or so, the voltage could keep climbing higher. That would be bad, since it will make light bulbs and the battery fail.

I've never seen a electronic voltage regulator fail like that Jim .... just the old selenium rectifier type I know that happens on cars but does it also on bikes ???
Bob.......

[Triple Jim]

Originally Posted by Bob KellyIII

I've never seen a electronic voltage regulator fail like that Jim .... just the old selenium rectifier type I know that happens on cars but does it also on bikes ???
Bob.......

A regulator can fail in one of two ways. One is that it won't pass current to the battery, so the battery runs down. The other it that it quits regulating, and passes all the alternator output to the battery, ruining the battery and if not fixed, eventually a lot of light bulbs.

[superkain]

I've hear that the 300's at least had issue with popping out of gear. on Mine it was 5th gear. Try changing to a different type of oil, and just put some miles on it; this resolved a lot of my issues.

[Norway]

Originally Posted by Bob KellyIII

Pull the battery and charge it to full... and see if it holds it's charge ...if not the battery is toast.... it should read 12.5 fully charged and should hold that charge for weeks..... if you charge it up and it goes back down to 11.5vdc over a few days...the battery is on it's last leg and needs replaced.
.....
Bob.....

May have been the battery, yes.. It was empty, and I had to jumpstart it when going to work recently. Drove for about 40 km, and it didn't start when I should return either, without jumpstarting it again. I have charged the battery (CTEK charger) and now it runs fine again.
Guess the battery might be near the end of it's life.
It's the 2nd battery after I bought the bike new in February 2012. Think the original battery lasted 8-9 years. (The bike has just passed 68 000 km / 42500 miles).

[Bob KellyIII]

in the 1970's you had to replace the battery in a motorcycle every year or at best every other year..... now days the batteries are much better.... but they will rarely last more than 4 years in a row !!! so when in doubt just replace the thing ! nothing worse than going to the bike after work and finding your battery deader than a door-nail !
also be real careful about jumping the battery so you can start it... I've done it and got away with it several times but other times I have fried the voltage regulator !
it is better to remove the battery , charge it and put it back in than jump start a bike
and never jump start a bike with the car running to charge the battery just use jumper cables to the battery on the bike and to the car battery....(car not running) and you SHOULD be fine.... no guarantees by any means !
.....
Bob......