Charging issue/question

My 82 gpz750 is not charging enough. I purchased a new battery a few days ago, it shit the bed immediately, so I bought a new one yesterday and did the whole rain dance to make sure it was good. I installed it today after testing it, showing 12.6 volts. Installed and started, the bike was charging at 12.5 volts at idle. At 4k rpm, I was getting 13.2 volts.

I spent part of the day earlier pulling bullet connections and cleaning them. Essentially, if it was electrical, I pulled it and cleaned it with either electric cleaner or steel wool. After hooking it all up, I'm now getting 12.8-9 at idle and 13.9 at 4k rpm. I have the factory manual and I know it needs to be higher at idle but my question is basically what could cause this? Does it sound like a rectifier? Something else? Do I need to continue to focus on grounds?

The main ground to the between the engine and the battery is the most important one here, but yeah, clean and tighten them all. You may just need a new regulator. You can probably get a Chinese one for $30. Despite what people who haven't tried them will tell you, they're just as good as the $100 ones. At least having a spare will let you determine if the regulator you have is faulty.

I won't have anything Chinese touching my Jap bike, let alone fastened to it... :evil:

Bitter enemies :whistle: .
Steve

daveo wrote: I won't have anything Chinese touching my Jap bike, let alone fastened to it... :evil:

+1,000 ! I wouldn't even consider putting a Chinese tire valve stem cap on my bike! Everything they make is junk!

If you discover you need a new regulator, rectifier, or combo unit call the folks at the link below. There stuff is the best money can buy and their prices are quite reasonable. I'm one of their many happy customers. Ed

www.oregonmotorcycleparts.com/Products.html

If you truly want the best R/R available on the market today you need to get a Series type R/R like a Compufire or Shindengen SH775. The Shindengen is much cheaper. Polaris OEM # 4012941. You can find these brand new for about $70. To connect it to your bike Triumph sells a nifty harness which will provide the plugs you need...Triumph P/N T2500676

A series R/R will help protect your stator and the Shindengen is the standard OEM supplier for most of the Japanese motorcycles.

If not already done, would confirm the 4000 RPM voltage reading with a different volt-meter.

As jackleberry suggested, would assure that the connection where the negative battery cable attaches to the rear of the engine is in good condition and providing a good ground connection between the battery negative post and the engine. The negative battery cable terminal where it attaches to the engine is subject to corrosion and deterioration.

If the negative battery cable has been relocated to the chassis, put it back to the engine where it belongs (and may provide a better ignition ground), or add another ground to the engine.

Be sure that the engine connection is to raw aluminum and not to a painted surface.

Good Fortune!

I've done all of that. I sanded down the area where the ground is attached to the back of the motor, cleaned it, the wire end and the bolt, and I'm still getting 13.9 at 4k rpm. I checked the voltage with two different voltmeters yesterday. I'm pretty sure I'll need to Invest in a new regulator now. I want to ride so badly...

And now another question: all of the regulators I see have a different plug than mine. They claim to fit, but I don't see how unless I modify the plug or the female plug. Ummm.....

Before you spend money on an R/R try this experiment: probe into your + terminal at the R/R, and then put the other probe on the + battery post and rev the engine. If you get more than .2 volts that means you still have wiring losses. Next, do the same thing on the - output at the R/R and the - battery post.

BTW, 13.9 volts isn't the best but the bike will be rideable.

Nessism wrote: Before you spend money on an R/R try this experiment: probe into your + terminal at the R/R, and then put the other probe on the + battery post and rev the engine. If you get more than .2 volts that means you still have wiring losses. Next, do the same thing on the - output at the R/R and the - battery post.

BTW, 13.9 volts isn't the best but the bike will be rideable.

I recall seeing a post or two from you about this. I'm happy for the reminder. After lunch Iill get to this.

While 13.9 is rideable, I'm worried about that dropping and me being stranded. But I suppose I take that chance anyway on a 32 year old bike, yes?

Used to be 13.8vdc to 14.2v was a good 12v system.
What has changed, other then over charging the battery at 14.5vdc-15vdc and eventually boiling out the water?