low voltage on idle

[Guest]

hi guys,

I've put the multimeter across the battery with the engine running and i'm only getting around 12.5v.

if i rev the engine this goes up a little, 12.8v etc.

Should these old bike charge at around 14v when idling at 1100rpm?

(battery is new)

[Steve]

Only if your charging system is in IMPECCABLE condition.

It is not unusual to be a bit lower at idle, but should definitely rise with the RPM, if it is low.

.

[posplayr]

hi guys,

I've put the multimeter across the battery with the engine running and i'm only getting around 12.5v.

if i rev the engine this goes up a little, 12.8v etc.

Should these old bike charge at around 14v when idling at 1100rpm?

(battery is new)

if you want to know what your charging system should be doing do the Quick Test in my signature.

[tom203]

Do the quick test and correct things.
For comparison, I get about 12.8 to 13 volts at idle (lights on)-rises quickly and tops out at 14.2 volts.

[Oliverstrother]

So I've check the stator resistance, which is a good 1.3ohms per wire. Also no continuity between the wires and the frame.

but I'm only getting 12-14v AC out of the stator. Is this normal?

R/R is producing about 12-13v, between 1000-5000rpm

any thoughts?

[posplayr]

So I've check the stator resistance, which is a good 1.3ohms per wire. Also no continuity between the wires and the frame.

but I'm only getting 12-14v AC out of the stator. Is this normal?

R/R is producing about 12-13v, between 1000-5000rpm

any thoughts?

Yes do the Quick Test and thereby follow a more structured approach to your charging system diagnosis than you are are now.

[koolaid_kid]

So I've check the stator resistance, which is a good 1.3ohms per wire. Also no continuity between the wires and the frame.

but I'm only getting 12-14v AC out of the stator. Is this normal?

R/R is producing about 12-13v, between 1000-5000rpm

any thoughts?

What does the quick test say the AC voltage should be?

[posplayr]

What does the quick test say the AC voltage should be?

It doesn't, there is no point in having someone hardly qualified to do a test, try to draw logical deductions from inconclusive data or even erroneous data as to what the actual performance or suspect failures are.

The Quick test is usually something 99% of the people can do and if it is not and something they get wrong, it is immediately detectable by anyone looking at their data. Appropriate application of the diagnostic criteria, will yield a far more accurate, diagnosis of the behavior of the integrated charging system than most attempt I have seen people make with the traditional "stator pages". I'm not saying the stator pages are completely wrong. However most of the Phase B and Phase C tests are problematic in that most people are unable qualified to perform, don't understand the test and half the time don't even know how to read the meter.

In the case of the OP, you have another typical situation where an individual wielding a VOM performs their own set of tests not know why or what for and want help anything the results of their own ill conceived test procedure.

Having watched these regular occurrences here at the GSR as well as the typical endless questioning by the member trying to help them out, I developed the "Quick Test" as something that cut through 95% of the uncertainty of trying to make a diagnosis and leave the Stator Pages (especially the Revised Phase A) as a set of detailed test for verification of charging upgrade.

I would also direct every bodies attention to the link in my signature

GS Stators

for more discussion of the GSR and the legacy of support from Electrosport

[tkent02]

What does the quick test say the AC voltage should be?

It only tests DC. If it's good, the AC must be good enough.

If there are problems, you have to dig into it more.

[koolaid_kid]

Ah. Never ran the quick test, ran a different one on my bike.

[Oliverstrother]

Have measured the AC voltage across the stator output.

At 5'000rpm I can reach 63V. (idle voltage is between 15-17v)

The maintenance manual recommends replacing the stator if the voltage measures below 80V.

I was going to replace the stator, then continue to work through options at improving the rest of the charging system. Thoughts on this?

This was the stator I was interested in.

http://www.electrosport.com/street-bikes/suzuki/gs650e-chain-drive-81-82/stator-suzuki-gs450-gs500e-gs550-gs650-gs750e-2.html

Can anyone else recommend a good quality stator?

Other quick stats (after 5-10mins running from a fully charged battery)
1.) key off................Normal 12.7 volts-12.9 volts (Actual 12.3, 13 if I charge the battery first, battery is new)
2.) key on (but not cranking with lights for 10 sec).....Normal 12.2-12.5 volts (Actual 12.0v)
3.) at idle (1500 rpm).....12.6volts - 13.2volts (Actual 12.3V)
4.) at 2500 rpm 13.5 -14.0 volts (Actual 12.7V)
5.) at 5000 rpm.....14.0 -15.0 volts (Actual 13.0V)
6.) key off.....slightly higher than measurements # 1 (12.8-13.0v) (Actual 12.4V)

Appreciate the help guys. Always appreciated your thoughts.

[Steve]

This was the stator I was interested in.
http://www.electrosport.com/street-bikes/suzuki/gs650e-chain-drive-81-82/stator-suzuki-gs450-gs500e-gs550-gs650-gs750e-2.html

Can anyone else recommend a good quality stator?

Seems to be about the going price, but I can save you about $40.

I have stators re-wound and offer them for sale, and include a one year warrantee, all for $85, shipped.

I do ask for your old stator in return, but don't have to have it first. Just send it back when you get your 'fresh' one installed.

At the moment, I only have newer, 18-pole stators available, but can get the older 12-pole units when needed.

.

[posplayr]

Have measured the AC voltage across the stator output.

At 5'000rpm I can reach 63V. (idle voltage is between 15-17v)

The maintenance manual recommends replacing the stator if the voltage measures below 80V.

I was going to replace the stator, then continue to work through options at improving the rest of the charging system. Thoughts on this?

This was the stator I was interested in.

http://www.electrosport.com/street-bikes/suzuki/gs650e-chain-drive-81-82/stator-suzuki-gs450-gs500e-gs550-gs650-gs750e-2.html

Can anyone else recommend a good quality stator?

Other quick stats (after 5-10mins running from a fully charged battery)
1.) key off................Normal 12.7 volts-12.9 volts (Actual 12.3, 13 if I charge the battery first, battery is new)
2.) key on (but not cranking with lights for 10 sec).....Normal 12.2-12.5 volts (Actual 12.0v)
3.) at idle (1500 rpm).....12.6volts - 13.2volts (Actual 12.3V)
4.) at 2500 rpm 13.5 -14.0 volts (Actual 12.7V)
5.) at 5000 rpm.....14.0 -15.0 volts (Actual 13.0V)
6.) key off.....slightly higher than measurements # 1 (12.8-13.0v) (Actual 12.4V)

Appreciate the help guys. Always appreciated your thoughts.

1 and 2 indicate the battery is good, even if the battery voltage is a little lower than normal room temp. No news since it is supposed to be new.

3.) Show you are producing something
4.) Shows a little more
5.) Shows even a little more but in all three cases well below where it should be.

6.) confirms that you charged some but as noted well below what it should. The progressively increasing voltage says that it is not bad connections, it is lack of current (low stator output).

You AC voltage measures indicate an issue with the stator. There is a revised Phase B test to look for shorts to ground which is very reliable.

From the tests you can pretty much rule out at least the R/R diodes but you never got high enough to insure it is regulating. The stator on the other hand is low in the presence of low charging voltages.

The diagnosis is the stator is bad, you can further confirm with Revised Phase B tests.

Link to Revised PHASE B of Stator Pages with discussion of testing methods:
http://www.keepandshare.com/doc/3977...4-pm-649k?da=y

[Oliverstrother]

All of these stator checks are all looking for a stator which output less that 60v at 5000rpm. (with/without load on the circuit)

My stator will produce more than 60v, but I don't see more than 13V on the other side of the rectifier.

It is possible for a stator to produce 60v @5000rpm between any two of the three legs and still be defective?

Cheers!

Ollie.

[posplayr]

All of these stator checks are all looking for a stator which output less that 60v at 5000rpm. (with/without load on the circuit)

My stator will produce more than 60v, but I don't see more than 13V on the other side of the rectifier.

It is possible for a stator to produce 60v @5000rpm between any two of the three legs and still be defective?

Cheers!

Ollie.

Yes, read the link I provided. Phase B Stator testing is notoriously problematic. The Revised Phase B testing includes Leg to Ground tests.

The leg to leg testing is hit or miss. The Leg to ground testing is much better but only a necessary condition not a sufficient condition. That means you have to pass to not be BAD, but passing doesn't mean you are good. The leg to leg is similar, but even worse as a predictor.

I have done everything but read the revised tests for you, just review the updated links.

And I'm pretty sure the AC open loop tests are supposed to exceed 65V at 5000 being more typically 80VAC. Look it up in the manual.

Do the revised Phase B tests.