Bad stator or bad volt reg or is everything ok?

Buying a 2003 VFR. The owner says battery is dead. I buy new battery and bring it to the test ride. The battery store I bought it from said to keep it on a tender as he didn't think the battery was fully charged (why the hell are you selling non-charged batteries??) He said it was at 12.3 and liked them at 12.5. Whatever. Put new battery in, bike won't start. Check voltage. 11.3. Jump start the bike to do the test ride. Get back after 15 min and shut bike off. Bike still won't start. I figured 15 min should have charged the battery. Decide to leave it with the owner so he can charge it and try again tomorrow. I advise him to jump start bike and check voltage while the bike is running. He texts me a pic of the bike with it running idle at 13.79. Ok, so that's enough to put a charge on the battery right? Now I'm convinced, "hey nothings wrong". The owner however is concerned because the Haynes manual says it should read 15 volts when rev'd to 5 or 7k rpm and he said it stayed at the 13.8 range. Am I being too picky? BTW, it's been cold here in Seattle. Low 20's at night.

Oh, and looking forward to officially owning my first VFR

Thanks!!

Jordan

 

You need to have a fully charged battery. 12
78 or up to 13.02 or so. The charging system will not be adequate to bring it up if its drained. You could bring it by a bike shop that has an appropriate battery load tester. The car ones are no good.

 

Oh this is a tricky one in a way, yes at idle that's a good number at above 2000rs I'd like to think you would see close to14 something in the environment your in. Yes it's been cold up here. Getting kinda tired of it myself , 20 this morning. Yes the VFR likes good voltage, my turn on the key shows the voltage is 12.8.v, once it fires up it goes 14+, then after like 5 minutes it settles down to around 13.8-14.0

 

13.8V is plenty to charge a battery and within the "normal" range, and suggests no issues with stator or RR. I'd be checking the wiring connections for any corrosion especially the 3-yellow wire connector between the stator and RR. These get dirty, resistance increases and the heat generated can melt the plug and let the conductors touch. Many of us have cut the connector out and hard-soldered that joint.


Sent from my iPhone using Tapatalk

 

Hi Jordan and Welcome to the MadHouse from the other side of the pond:welcome:

It sounds like you have not yet committed to purchase this VFR - so before you do you really should spend time to plough through the following thread. Yes it was initially written for 5th Gen models but much the same issues, and tests arise with 6th Gens too.

http://vfrworld.com/forums/showthread.php/39277-How-to-fix-common-regulator-Stator-failures

To be honest 13.79v at idle is not too worrying, but the RR should indeed be delivering significantly more (approaching 15v) once the revs are at 5k. It does sound like the RR is failing or one leg of the stator is in trouble - hence if you are not familiar with charging system fault diagnosis - I strongly advise you read through that thread - yes the same thing is covered several times - and yes the 2003 models are prone to issues.

Inherently all 4 elements of the charging system(battery, RR, Stator and loom) need to be in good order and a fault in any one can quickly damage some or all of the others. To really understand what is happening you need to get a multi-meter and a healthy fully charged battery and then do the tests explained in post #9 TWICE - once with the bike cold and repeated as soon as possible after the bike has been for a 15minutes plus ride by which time the charging system should be fully warmed up and intermittent heat related faults may become detectable. Sometimes a stator will work fine whilst cold but insulation on windings may fail when hot so instead of charging the bike it can start to drain the battery leaving you stranded.

If you do find a component is faulty please do not automatically assume that simply replacing it will mean the problem is solved. The stator-RR connector, and main fuse by the battery on early vtec's are prone to melting and can then short out the stator, and potentially kill the RR and battery too. So whilst it may seem a chore it is always a good idea to repeat those tests once you think you have identified the problem just in case something else needs attention. Once you get clear cold and hot test results you should be good to go.:vtr2:

As for "jump starting" the motorbike - it can be done - but please make sure the engine of whatever vehicle you take a jump start from is not running, or you risk killing expensive electrical circuits in the motorbike. Charging systems on motorbikes are not like cars where it is usually recommended to boost start with an engine running.

If you do decide to buy that VFR don't forget to come back and post up some pictures - or people will be raggin on you fairly soon!!!

Also check out the R3 event post - which may be of interest and a great way to discover how well VFRs can cover huge distances - and you can be sure to meet up and ride with some of the folks on here.

Take care - ATGATT



SkiMad

 

Yup, looks fine to me... Mine does not even pass from 14.2v but my case could be different as i'm using a fa012ab reg/rectifier from a triumph... But hey, my bike holds the battery charged and everything works fine