My 82 Katana is running with an issue maybe

[roy826]

Charging system seems weak. It has a brand new well charged up AGM battery made by Yuasa sold by interstate batteries. It’s only putting out 12.62 at about 2k rpm’s, tach needle is broken off and the remainder piece is not moving much so I could be off on these rpm’s. At 5k it does get to 13 on output. When I cut bike off battery is showing 12.3 and when plugged back into my battery tender it stays on red for an hour or so until green.

Im not and expert on this but I think the rectifier is toast. I see the headlight getting brighter when I rev it up but on the meter it’s just not putting out enough juice. Bike has original stator and rectifier. Should I suspect the stator as well? I just got the bike cranked today after sitting the past 13 years in an old shop unseated or cooled. Carbs were a mess but I sorted all that out. It had several other oil leaks and issues I’ve sorted all out. Bike is running smooth and good but it’s the charging or lack of and I do not want to ruin a nice new $111 battery. I plan to order a Ricks rectifier for it. Suppose to be a direct plug in for $98 bucks.

Any help on this much appreciated. Thanks in advance.

 

[Rich82GS750TZ]

Your story is a common one, I?ve linked my charging system saga in my signature. It?s pretty typical. Read the whole thread, you?ll learn a lot. One of the electrical gurus, posplayr, isn?t on the forum anymore. But he did help me a lot. A have links to a lot of his writings in that thread.

Yes, suspect your stator as well.

No, I cannot recommend a Ricks RR. But I can recommend a used Shindengen SH775 for half the money.

Not sure why you?d pay that much for a battery.

 

[Redman]

///////////QUOTE
At 5k it does get to 13 on output. . . . . .
...
I see the headlight getting brighter when I rev it up
....
///////////EndQUOTE

So, it is charging, some, but not well. So, R/R is rectifying and regulating.
I would more suspect weak stator and/or bad connections somewhere.

Check the 3 voltages (AC) from the stator, disconnected, at about 4K rpm.
Look for heated-discolored connections, stator to R/R, and R/R to fuse block.

 

[roy826]

Understanding anything electrical I might as well be reading Chinese. I know how to read a multi meter to get voltage and that’s about it. My dad was the electrician in my family but he passed away sept 1st of this year. I never picked up any of his knowledge on it.

Sounds like all parts are not made of equal quality from my google researching this morning. How does one go about testing the stator and R/R? In the simplest terms possible for me. I’ve had that stator cover off in the past so I know how to remove it and put it back on. R/R is easy yo access on this bike. I’ve traced its connections down already. I’ve never messed with the stator with cover removed or never unplugged it. I had the cover off long time ago when it spun the stator/flywheel thing on the end of the crank. I repaired that without totally removing the stator cover or unplugging it. So where do I test the stator from? I do not have a service manual just the owners manual and google.

 

[Rich82GS750TZ]

Read 2 threads in my sig regarding charging. The info in the second one was dumbed down (for me), so you should be able to follow it as well.

You should create a signature of your own to include your bike year and model. Go to settings, top right of any page.

Check BikeCliffs website also linked below. Not sure if there’s a FSM there for your model or not.

 

[Redman]

Sorry about you recently loosing your dad.


Stator test are easy. See what Rich has referenced.

To test stator do not need to remove it, do not need to remove the stator cover.
Do need to find (and disconnect) the stator wring from the R/R. And do need multimeter (that you mentioned) (measure AC volts, and ohms).

Testing R/R is not so easy.

 

[roy826]

Ok I’ve managed to test the stator not running and getting inconsistent quick numbers flash up on all 3 leads. The numbers don’t stay on the meter long. Very confusing. I have not tested it running yet. I followed one of Ricks YouTube videos on the R/R diode test and it was consistent on all except the positive connected to ground wire and only one of the 3 leads posted a number. I think I need both stator and R/R based on the wild numbers or lack of I’m seeing.

 

[roy826]

Ok o tested running not sure if I had meter set right but at idle on ac it was 23-25 and revved up around 30. Wiring is getting warm to touch at stator connectors to R/R. Not sure if that normal or not. At 5k rpm’s it’s putting out 13.54 with meter on battery on volts. Little higher than yesterday but I cleaned the butt connectors at stator to R/R and the R/R ground connection. Still not charging enough for me.

 

[tom203]

Put your meter on 200 VAC spot??measure between the three stator wires?with stator disconnected from r/r? at least 4000rpm. Look for readings at least 60 volts AC between any two pairs .While your at it ,measure from each of the stator wires to bike ground. Anything much above 10 volts indicates your stator is grounding out.

 

[roy826]

Will do that, makes more sense that way.

 

[roy826]

Ok it’s putting out 60 on all leads disconnected from R/R at 4K rpm’s. Less than 5 on each lead connected to a ground.

 

[Nessism]

60 VAC is low. A strong stator will put out 80. Also realize that no load tests are not ideal.

If you have the money I'd get a new Rick's stator and a used Shindengen SH775. There are tons of threads on how to hook up the R/R. Hint: the best method bypasses the factory wiring.

 

[Nessism]

I looked around on ebay and couldn't find any good deals on used SH775's. There are quite a few R/R's that MIGHT BE SH775's, but the ad doesn't show the printing on the top fin.

Search Polaris, Sea Do, Can An, Regulator or retifier and then make sure you can see SH775 printed on the top fin. Also, make sure you can see the plastic tabs on the connectors. Hacks often break them off. Message the seller if you see a good looking unit that doesn't show a photo view of the top fin. I've found lots of good units this way.

Here is one as an example. A little spendy is all...https://www.ebay.com/itm/1249461774...75f5dd2:g:mMAAAOSw9tlhY3fo&LH_ItemCondition=4

 

[Nessism]

Here is another...https://www.ebay.com/itm/265438446349?epid=1834197494&hash=item3dcd5d430d:g:VAAAAOSw1aJhrXTC

 

[roy826]

Ok it was making more than 60 on the meter I just thought it needed to make at least 60 from the previous post. I saw 75 up to 80 on all 3 legs at only 4k rpms. Money is not a issue. I'm already a grand into this thing bringing it back to life and still have new tires/tubes and the freshen up paint job back to oem. I can do the Ricks stator but the SH775 R/R makes me nervous with the modifications I am not comfortable doing. Plus the R/R on the Katana is visible on the left side of the bike right next to the exposed fuse box. No side panel covers any of that area. I do think the oem R/R is bad based on my testing it using Ricks video.

 

[Rich82GS750TZ]

Roy, listed to Ed. Stop thinking about the modifications as “Rewiring” or “Electrical Work”, scary terms for most of us who’s fathers didn’t show him how to use a voltmeter. (Yes, me too. Dad taught me a lot before he passed, but not volts/ohms/watts). I was in your same shoes. Think of this work as improving what the factory made. These fellas got my bike and many others sorted better than stock. To attempt to keep the factory wiring “stock” around the GS’s charging system would be a mistake and an oversight. Don’t take my word for it. There’s enough documentation and testimonials here and elsewhere to prove it.

 

[roy826]

Roy, listed to Ed. Stop thinking about the modifications as “Rewiring” or “Electrical Work”, scary terms for most of us who’s fathers didn’t show him how to use a voltmeter. (Yes, me too. Dad taught me a lot before he passed, but not volts/ohms/watts). I was in your same shoes. Think of this work as improving what the factory made. These fellas got my bike and many others sorted better than stock. To attempt to keep the factory wiring “stock” around the GS’s charging system would be a mistake and an oversight. Don’t take my word for it. There’s enough documentation and testimonials here and elsewhere to prove it.

Oh I believe you but I am not sure I have the know how to make this any better or to make it even work. I am capable of many things when working on mechanical stuff with a motorcycle but wiring and plug in change outs and rerouting wiring is not one of my gifts. I have read about all this until my eyes have crossed the last 24 hours following links to old discussions and links to items needed.

This bike will rarely be ridden as is. I am just putting it back to a nice physical and running condition and of course that involves replacing a lot of stuff along the way because it'll be 40 years old come Feb 2022.

So is it safe to assume buying a new stator is the way to go if I tackle this R/R revised setup? Sure hate to rewire all that up and fab this R/R replacement on and the original stator kill it to.

 

[Nessism]

For a collectable bike where you won't be riding it much, I'd stay with the stock R/R. Worst case, it will take out your stator, but it won't happen quickly. One thing I'd do for sure though is rewire the system to cut out the stator loop. Basically, send the three stator wires straight into the R/R, bypassing the stock harness. This is easy and can be taken at face value.

 

[roy826]

The stator 3 wires go to the R/R as is now. From there the R/R has two other wires coming out of it one is red that plugs into the bikes harness and the other is a ground that is grounded to battery box back.

 

[Redman]

The stator 3 wires go to the R/R as is now. ...
...

I was going to say that the most of the "rewire" is to connect all three of stator leads directly to the R/R (rather than on leg thru a buch of connectors in woring harness), but now you say that has already been done.

. From there the R/R has two other wires coming out of it one is red that plugs into the bikes harness ...........

That is okay, in my opinion. But is often where might be loosing a volt or good fraction of a volt, where that connects into the wiring.

. ..... ....
the other is a ground that is grounded to battery box back.

That is okay, in my opinion, IF that point is well grounded. Problem is that the battery box is not itself well grounded (since is rubber mounted), and relys on a ground wire from the bike harness to ground it, and sometimes that wire is not a good ground (or maybe it was untill a R/R problem dumped a lot of current down it and melted it away where it does connect to frame above/rear of battery, I think). Anyway, so a typical recomentation is to run your own additional ground wire from that point on battery box (solenoid mounting bolt) to the frame or batteryNegitive.

Other comment: I think the fact that you describe this so well, shows that you will do okay with this.