86vmax battery or charging issues

[purekb]

Ok little history. This is my first bike a 1986 vmax. I have been running the bike for the past 2 weeks with no issues at all other than getting used to the freaky amount of power it has. Ok on to the problem. I noticed over the weekend it was having problems starting. To me sounded like a weak battery. then monday morning it would not start at all. So I put a jump box to it and it started right up. Went and removed the battery and charged it up. 12.7 was all she would take. put it back into the bike and she started right up. So I went for a ride. got about 4 miles from where i started on the highway and she died on me and would not restart. got a friend to bring the jump box and started up again. made it about 4 miles and she died again. 2 more jumps and im back at work. battery reads 12.16v with bike off. start bike and reads 12.25v. rev to 2500rpm reads 12.39v. rev to 5000rpm reads 12.21v. got a new battery coming today cause from what i have ready here it should be in the 13v range fully charged. but shouldn't the bike stay running just from the stator?
please any ideas would be greatly appreciated....

 

[maleko89]

The problem is with your rectifier/regulator. If that's bad it doesn't matter how much your stator produces. If you go to the electrical section you'll see a sticky with the charging system fault finding .pdf. Use that to pin point the problem. 12.7 - 13.0 volts is about all your battery can hold. At idle you should be getting between 13.5 and 14.8 volts.

 

[Akatora]

Hello,

Yeah, see for example this thread: http://www.vmaxforum.net/showthread.php?t=1599

Typical points of problem are:
- bad regulator/rectifier unit (especially with the models older than -96)
- bad grounding
- "crimp fix" not yet done (this probably not the biggest thing)
- battery not in good shape
- alternator coils (charging coils) gone bad

If you end up to get a new regulator/rectifier unit, I warmly recommend to get one aimed for newer model (from 1996 on). This is bolt on and is much better than the old type that you probably have there.

Regards,

AT

 

[Buster Hymen]

On the left hand side of your bike, by the rear part of the frame there is a bundle of wires. Look in the bundle for a white connector that has 3 white wires coming out of 1 side. This is the connector that connects the stator to the rectifier/regulator. This connector is notorious for melting/burning or corroding causing a non charge situation. Take it apart and check it out, this is a good place to start. Keep us up to date on what you find and we can help you out.

 

[lankeeyankee]

I disagree, I have seen many chase down rectifiers stators etc. If a battery has a collapsed cell it will pull down the reading. Wait till you get your new battery. Test the battery once installed, than start the bike and check the voltage of the battery.

 

[cjmeg]

As you already have a new battery coming, that (should) isolate the battery fault.
On my '85, the reg was new, electrical grease on the connections to the frame, and I was told by the previous owner stator was U/S.
Battery wouldn't charge, 12.8v at idle
The crimp fix had not been done, so I did that.
Also ran a direct earth to the reg and a heavier to the frame from the battery.
I also replaced the plug that the 3 white wires from the stator uses.
Now it runs the magic 14.0 at idle. No more dramas.
Next battery I will replace with the Panasonic guys rave about for these animals.
I would take your time and persist- each of these guys makes a good point. You will beat it.

 

[purekb]

ok worked on it some last night. I first followed the flow chart and according to the chart i had a bad connection to the pos side of the battery. now the sodering had already been done. so i cleaned all connections i could find having to do with the red wire coming from the R/R going to the pos battery terminal. after that is was charging at 13.4 at 2500rpm. so i though cool should be all fixed. well drove around town for about 1 hour and thought man i got it pegged. just then I could feel it wanting to die. and it did. battery should be here tomorrow but it load tested fine cca were at 300. not exactly sure what its supposted to be cause it says nothing on the battery itself. well i push started it and after 2 tries and alittle choke she started up and ran fine home. I think just to do something today I will run a direct line to the battery with an inline 30amp fuse.(to big?) and a direct ground wire also. just to stay proactive. will probably order a new R/R soon. need to work another week before i can.
funny thing was that when i went to start it this morning it started right up did not even sound like the battery was weak or drained in the slightest.
i want to thank everyone who has responded to me. Thank You.

 

[purekb]

OK Update. i ran a seprate wire from the R/R direct to the battery with an inline fuse (30amp). and now at idle its charging at 14.04v. will run the ground here sometime today. at work now so i have to space out the work.

 

[Bill Seward]

Running the positive wire drom the R/R directly to battery negates the need to do the "Crimp Fix", as the current does not go through the crimp any more.

I soldered all 3 of the wires from stator to the R/R. don't worry about which wire goes where, it's AC current at that point, and it does not matter , as long as you don't connect 2 wires from the stator together, you're OK...

 

[purekb]

Ok so i dont think it helped any. went for a ride and it still died on me. Think the R/R is dying when it gets hot. beleive it might be time for a new R/R. I will make sure to get the updated one from 1996 or above.

 

[maleko89]

Is the charging voltage going down just before it dies?

 

[purekb]

yeah its dropping. i let in run in my shop and watched it. went from 13.9-14 volts and suddenly dropped to 12.6v after about 20 minutes running. R/R was burning to the touch hot at that point.

 

[maleko89]

Before dropping $ on a R/R I would test the stator and the connection between that and the R/R.

 

[purekb]

ok so i checked the connection between the stator and the R/R and turns out it was kind of melted together. i will try and bypass the connection and see if that helps.

 

[purekb]

ok so i connected everything back up and cleaned the grounds for the R/R cause it goes to the frame. bike at low idle no choke was at like 13.05 +/-
choke it to about 2000rpm and bike is charging at 14.07 +/- . i then let it get to temp and the fan kicked on. still charging at about the same rate.
let it cool down. now bringing it back up to temp to see how it does.
Maleko i think you were right on the money this time. with the connetion from the stator to the R/R.

 

[maleko89]

Great! You are getting the same voltage at idle I did when running the early model R/R. It barely charges..probably because Yamaha didn't want the battery juice boiling at idle. I gained almost 3/4 of a volt just by switching to late model R/R. You can get those for about $70 after discount from Mondak Motors. Listing for this vendor is in VMF Links.

 

[purekb]

ok took the bike for a ride and guess what....
died again on me. im at a lose for words right now.....$%@#&^%#$*(
so i guess once i stop sweating from pushing the bike a mile or so i will go and check it out but i need to wait or i will run it over with a semi.

 

[lankeeyankee]

You will be fine with a 30AMP main fuse... UNTIL you have a short and than it should be easy to find just follow the melted wire.
What do you have on your bike that totals 30 AMP draw?

 

[Buster Hymen]

ok took the bike for a ride and guess what....
died again on me. im at a lose for words right now.....$%@#&^%#$*(
so i guess once i stop sweating from pushing the bike a mile or so i will go and check it out but i need to wait or i will run it over with a semi.

Can you make a short list of what you have done? I believe you said you have a new battery and the charge voltage is about 14V. Also what are the symptoms it displays when it dies or is dying.

 

[purekb]

OK all i will admit I AM RETARDED. I figured it out last night. It had nothing to do with the charging system or the battery. God im such a moron. It was so simple too. The fuel filter was clogged. Thats it $3.88 and about 4 minutes worth of time. Thought it was the battery cause apparently when thses things are hot the dont like to start all that well and espcially when theres no fuel....... See MORON. o well live and learn. i just bought the bike. and never changed it. Again to all that have tried to help me.
THANK YOU.