Electrical woes

[jby1999]

Okay we bench tested the stator so we think thats out of the question!

Problem:
If bike sits wont start even if trickle charged to peak with batt tender. New batt so thats not the problem. Somewhere theres a short that drains the batt if not kept on charger. Batt will die in days
First thought is volt regulator can anyone confirm. Over the summer the thing got really really hot while riding and the volts were about 13.3 running idle and dropped to 12.5 at the lowest at 5k. but crept back up a lil to 12.78. Now being winter it will crank and crank no fire till batt is dead unless i jump it with my 50amp charger. New newa is it wont even stay running with a load on the motor just stalls and gotta jump it again. Im not a big fan on fryin a battery so any input would be good. I found 2 aftermarket volt regulators on ebay wondering how they compare to the stock yamaha one. Also the vmax guru around my parts recommends grounding the volt reg straight to the battery for a few extra volts to the system.

Bike:
1990 Vmax lowered 2", redid trans built by someone who races these things. Very tight i might add. New batt custom paint 180 rear tire. I need to get her running!!!!!



ebay volt regulator 1
http://cgi.ebay.com/ebaymotors/ws/e...STRK:MEWA:IT&viewitem=&item=250187477401&rd=1

ebay volt regulator 2
http://cgi.ebay.com/ebaymotors/ws/e...STRK:MEWA:IT&viewitem=&item=180135398118&rd=1

 

[RagingMain]

I bought the first one you have up there. Very happy with it. I still cannot reach 14.5 +/- .5v but it does maintain 13.9 which is close enough for me. My lights are much brighter and the bike seems to run better since the install. One word of advice, this R/R is thicker than the original so make sure you have the right length bolts prior to swapping it out. :bang head:

Also I cut the plugs on both the stator and the R/R and hard wired them. Not sure if it is necessary but gave me piece of mind over the plug.

Cheers:cheers:

 

[jby1999]

Thanks for the info ragingmain just not quite sure if im hunting in the right county if you know what i mean. If someone could tell me if this sounds like a volt regulator gone bad from expierence i would atleast be on the map. Thanx guys!

 

[maleko89]

Check for battery draw even when key is off.

Mark
#1098

 

[OU812]

Been there... New stator, r/r, crimp fix, eliminated most harness connecters,soldered all, solid grnd straps,batt. tender, bla-bla-bla... This animal eats a batt. a year no matter what the flaver or $$$... Every spring, I drop $45.00 on a middle of the roader and don't sweat it all summer... Just my exp. Good luck...:ummm:

 

[RagingMain]

Thanks for the info ragingmain just not quite sure if im hunting in the right county if you know what i mean. If someone could tell me if this sounds like a volt regulator gone bad from expierence i would atleast be on the map. Thanx guys!

checking the draw with the battery off will tell you if you have a ground.

The first R/R on your list came with an awesome troubleshooting guide which is posted on this forum in a sticky in the electrical stuff. This is what I used. It works great and easy to read.

Cheers:cheers:

 

[Bill Seward]

I bought an Electrex regulator/rectifier unit online. I've posted on this topic a few months ago, but I can tell you it absolutely fixed the starting/charging problem. I did all the usual fixes, soldered everything, ran wires directly to battery, etc. Still, a crappy regulator is a crappy regulator, and all the "fixes" out there aint gonna work, if you have the old type R/R unit.

Expect to spend about $60.00 or so, and you will have to lengthen the output wires to reach the battery, but-by directly wiring to battery-you eliminate the need for the crimp fix. All the possibly corroded connections in the wiring harness are no longer a problem, as they are not used.

Be sure to SOLDER everything, including the connectors you attach on the ends of the wires to connect to battery.

The 3 wires from R/R unit to stator should also be soldered. There is no wrong way to connect them, being 3-phase AC coming from the stator - any way is the right way.

Of course, check the AC output of the stator, when disconnected. Run the bike at about 2000 RPM, and look for AC volts across any 2 of the 3 wirse from stator. Do all combinations. If you have zero volts at any point - your stator is toast. Do this before buying any parts you may not need.

I think you're looking for around 45 VAC at this point, but someone here can correct me if I'm wrong......

My Max is an '85. I had crappy starting for 20 years, but learned to live with it. I never got a real solid charge to battery - even after the "fixes".. I read about the aftermarket R/R units, and bought an Electrex. Cheaper than a stock one, fir like original, and really fricken' WORKS! Went from a 12.5 volt charge to a 14.4 volt, which is as good as it can get.

Hope this helped - Mail me if I can help you more on this.

Bill

 

[Bill Seward]

One more thing - I THINK the R/R unit has a diode in it to prevent the battery from draining through it. If this diode failed, you may get the discharge through the R/R unit.

I may be wrong here, but I think that's how it works...

 

[4gasem]

One more thing - I THINK the R/R unit has a diode in it to prevent the battery from draining through it. If this diode failed, you may get the discharge through the R/R unit.

I may be wrong here, but I think that's how it works...

Most rectifiers are nothing more than diodes...:thumbs up: