Still over charging,getting frustrated!

I may have found the issue. When i last tested my rotor i got over 5,thats back when i had installed mikes unit approx a month ago but after going thru 4 tail light bulbs ect i finally realized that unit just would not work correctly and got the recommended vr-115,but as mentioned it seems to be working correctly till bike gets warm so i decided to check ohms on Rotor again,was not expecting any change there but its now down to 3.4 ohms .I removed both brushes to test and tried with 2 different testers.I guess i need a new rotor.To test the Stator for resistance do i remove brushes and use ohms setting from either slip ring to the Alternator case,if so what should the reading be. Whats quality like on Mikes rotor and stator?
 
Yes, at 3.4 ohms you are only getting partial charging. Mikesxs has a bad reputation for many different parts. Best to do a search for "alternator rotors" and see what you find. A much better choice would be to have your rotor rewound by www.customrewind.com down in Alabama. They have a reputation for first class quality. With a rewound rotor your alternator should be working 100%.

For the stator, you unplug the multipin connector,and measure across each of the pairs of white wires. 3 readings needed. Should be around 0.5 ohms. That small resistance can be difficult to read accurately. Take into account the resistance of the meter leads. Also, measure from any one of the white wires to the alternator steel frame.............this should be a very high resistance (unplug the yellow wire to do this test).
 
RT i did some testing,i put my tester on one off the slip rings and other to a good ground,regardless off
what ohm setting i get no reading,is that correct? The white and yellow wires u mentioned,is that the plug behind and yellow at the rear off the engine?
 
XS650D said:
RT i did some testing,i put my tester on one off the slip rings and other to a good ground,regardless off
what ohm setting i get no reading,is that correct? The white and yellow wires u mentioned,is that the plug behind and yellow at the rear off the engine?
Click to expand...

The slip rings are part of the rotor..............you already know the rotor is defective. Its the stator you want to test. Yes, its the only connector with 3 whites in that area. The yellow is a single wire all by itself.

When measuring from the rotor or the stator, to ground, you expect to see very high resistance (infinity ideally). I don't know what kind of meter you have. Search on Google to find an explanation of how to read your specific meter, maybe a Youtube video will be found.
 
Ok RT,Did some more testing for Stator,got .5 Ohms on all three white wire combo.I tried same test with bike running BUT plugs and yellow reconnected set to AC at idle and 2 whites show approx 13 and one shows 14 Volts AC.(As per testing info above attachment) Is that a sign that my Rec is not working correctly (Original Rec)
Plug wire connections are clean to Rec and Stator.
 
Just got back from a ride and got the motor got and hot,tested the white wires at idle (1500 rpm)
on AC and 2 white combos showed 14.5 and one combo showed 17.2 Wow!
What result will that have with a high reading?
 
According to step #6 in post #1 of the charging guide linked to in post 43 above, that could indicate your rectifier is bad. But, the readings were taken at idle. 1200 is idle. I don't know for sure but 1500 might change the readings?

That step #6 says AC volt readings should be about 10.5-11. He calls high readings 16 to 18 and if it happens on any of the legs (wire combos), the rectifier is bad. You have 17.2 on one of the legs. But, like I said, I don't know if RPMs will effect the reading. I'd test again with the idle turned down to 1100 or 1200 to be sure.
 
I would not be concerned about the AC voltage readings at this time. Your stator windings have the correct resistance so that looks good. Since you are planning to replace the rectifier, I would complete that job and then see what measurements you get as far as the DC voltage at the battery.
 
OK thx Guys,Should have new Rec and Rotor in few days.I do find it odd that one leg off the
white wires is much higher.Once my bike motor is really hot it will not idle under 1500 rpm.
Yes the readings were much lower when all was cold but one leg was still much higher.
Thx for your patience and stayin with me on this issue,As mentioned many times,electrical was never my strong suit but your training is paying off.
 
What do you mean by the bike won't idle any lower than 1500 when hot? Do you mean that if you do adjust it lower, it just stalls, or it won't go any lower even with the idle speed adjusting screw on the left carb backed out all the way so it isn't even touching the cable arm? If the later then your carbs are not in sync. If the carbs are properly synced, you should be able to turn the idle speed down to nothing, effectively shut the carbs off, and stall the motor.
 
5T i have a bad left carb and gettin it perfect is a problem,yes i can back off
the Idle adjuster completely but when really hot on stand in garage it will do this and
not come down any lower.I do have the oil filled Red neck Sync adjuster and have them
set up,my plug color is perfect both sides when on the road.My bike has always done this
regardless off what jetting is in it when hot.
 
As 5twins said, you normally should be able to lower the rpm down to less than 1000 rpm before the engine stalls. Its very important that both butterflys in the carbs are able to close fully. Regardless of what sync adjuster you have, I would recommend you remove the carbs, and confirm that both butterflys are able to close fully.Once you know they can close fully, I use a piece of paper as a feeler gauge under each butterfly as a bench sync, which has them just about perfect. Also make sure your ATU is free to rotate,and fly-weights snap back smartly. Any air inleakage around the carbs or manifolds will keep the idle speed high as you are having.
 
I think I recall reading in one of his past threads that he had the butterfly plates out, couldn't get one back in so he filed it. Basically, he has a bad plate now I think. Replacement is probably the only solution. Yamaha never did sell that part so scrounging one is the only option. I repaired a set of BS34s that way. The P.O. went hog wild with a file and really screwed the plates up. Even closed, they weren't closed. You could see light all around them.
 
5twins said:
I think I recall reading in one of his past threads that he had the butterfly plates out, couldn't get one back in so he filed it. Basically, he has a bad plate now I think. Replacement is probably the only solution. Yamaha never did sell that part so scrounging one is the only option. I repaired a set of BS34s that way. The P.O. went hog wild with a file and really screwed the plates up. Even closed, they weren't closed. You could see light all around them.
Click to expand...

Oh yeah 5T, if he took a file to a butterfly, that would like be the death of the butterfly. I think the butterflys are made to a very close precision dimension. If not a perfect fit in the bore then a high idle for sure.
 
Wow Guys,never took file to Butterflys,Not sure were u got that info.I did have them out,yes but
one did not slide closed perfectly so ever so slightly water sanded the mouth off the carb were it was catching
to get it to close.Reason i had a high idle was i had the pods off and bike was very hot.My left carb has always run a bit leaner than the right and have been thru them many times,i think its the air screw,previous owner may have really torqued it down and opened up the opening.(i believe this was a problem on 76/77 carbs) I find that i need to be 3 turns out on that carb and 1.5 turns out on other to get it to idle right.My main reason for posting is that i FINALLY got my bike to charge correctly after a long month of screwing with it.The VR-115 helped but a new Rectifier solved everything.Did not need a new Rotor or Stator.Bikes has never run so good!
Thx for all your help and stayin with me on this,especially on the Electrical,I have never used my Tester so much!
 
You previously said your rotor was only 3.4 ohms. Is that still true or not??
So what is the battery voltage when rpm is 3000 or greater?

If the butterfly drags on the side of the carb bore, it is remedied by loosening the butterfly screws and then allowing the butterflys to snap closed. That will cause the butterflys to aline themselves with the carb bore. Screws are then retightened (with some blue locktite). Sanding of carb bores or butterflys would be a bad thing to do, as they are both a precision fit from the factory.
 
RT,Actually kind of feel silly,when i last checked the slip rings i was doing it wrong,it is still 5 .5 Ohms!
With the new Rec the white wires are all showing 10.4 AC at 1200 rpm .Battery Voltage is now 14.3 Volts with engine hot or cold running and i dont have to hold the throttle for a while to have it run up to that voltage like before,just shoots right up and comes back down rite away with throttle.The change of both rec and reg solved everything,bike seems to run better also.I think my electrical problems are finally done!
Thx for tips on carbs.
 

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