is my alternator knackered???

[stooster]

hi all..

my sv650s w reg wouldnt start the other day...

charged battery and still wouldnt go...battery dropping down to 5 or 6 volts when starting up...

fitted new battery today and started well...so i ran through charging sytem checks and got the following..


leak test 0.2
battery = 12.7dcv
battery at idle (lights on full beam) = 12.3dcv
battery at 5000rpm (lights on full beam) = 12.2dcv

I thought my R/R was knackered but went on to check ac output of alternator...and only getting 23v across each of three wires:(

I assume the stator is knackered but i find it strange when i measure coil resistance of alternator all 3 measurments are 0.6 ohms and none of them are down to earth...

is this normal.....do i need to order a new stator or would it be repairable..

cheers for any help

stu

[Spanner Man]

Good evening.

Did you do the alternator test at 5000 rpm? You should see around 75 volts. If you did test at 5000 rpm it's likely that you have a problem with the stator, despite getting continuity on the wires & having no continuity to earth.

If it tests ok at 5000 rpm it's probably the RR unit.

Cheers.

[Alpinestarhero]

Question: Why do we test at 5000 rpm?

Matt

[Spanner Man]

Good evening.

A permanent magnet alternator such as the SV's will continue to pump out increasing AC voltage the higher it spins.
I think you'll find that if all is well with the charging system after 5000 rpm the regulator will start to errrr regulate, & start to lose the excess AC voltage as heat. Therefore if the alternator is to specification at 5000 rpm it is capapble of supplying the bikes demand.

Cheers.

[stooster]

cheers for that spannerman.....was gonna strip down tomorrow but just measured it again at 5000 rpm and getting 80-90Vac...

retested the battery and got 13.2 at idle then 12.9 at 5000rpm so yes it seems my RR has gone....

whats my best option regarding replacement...

cheers

stu

[Biker Biggles]

I put a Honda CBR600RR one in mine and it's spot on.

[stooster]

I put a Honda CBR600RR one in mine and it's spot on.

i read on here that they are suitable.....does the year matter........my local breaker just told me hes got a 1995 cbr600 that he is ready for stripping.....would this be suitable...

how much should i be looking at paying...

cheers

stu

[mister c]

I used a GSXR one, it has been fine for the last few months. The unit is larger, but still sits under the bodywork fine. You may have to chop some wires & do some soldering, but it's dead easy.

[stooster]

ok ..cheers for the advice fellas....the cbr RR will costr me £25 and im gonna try it on the bike first so sound like jobs a good un...

what do i need to do excactly to try this....ill solder it and make it all nice and insulated when i get it home but as a quick test if the plugs dont fit im hoping i can just use a couple of wires between plugs...

i know i have three wires from alternator to reg and 2 from reg to battery....is the cbr600 the same and if not what is it likely to have...

cheers for the responses so far..really helped me out here...not nice when your bike dont start is it...dont like getting the lammy wet;)

[andywilson460]

I got a 2nd hand one from SV spares for £35 - which seems to work (since the weekend) - pain in the **** to fit into a pointy though

[Biker Biggles]

I used a much newer Honda one (2004?)and there were too many wires ,but I just spliced the duplicate wires together to make three.

[Spanner Man]

Good morning.

It sounds like your alternator is ok, good show.

The RR unit from a 1995 CBR600 is considerably different to the one fitted to the later CBR's. Namely it doesn't have separate input & output leads coming out of it. There's a single 5 pin plug on the loom which plugs directly into it, also the live & the earth terminals are 10mm wide, & 'female' connectors are difficult to obtain in this size.
In my opinion Honda RR units are amongst the worst around, for over the years I have changed more units on Hondas than on all other makes combined. Some of which I suspect is due to deficiencies in the alternator design, which leads to the alternator spiking. I know Pete at Electrex winds his Honda alternators in a different fashion to the originals to help prevent this.

Your best bet would be to go for a RR unit from a GSXR, as they seem to be reasonably reliable, or go for a new Electrex unit. They are around £75 & have a 12 month warranty. their number is; 01491 682369.

An RR unit from a later CBR as Biggles has fitted may be ok, I tend to stay away from Honda RR's full stop! But as some of the RR problems on Hondas are attributable to the alternator there's nothing to suggest that they wont work reliably when fed by an alternator on a Suzuki.
If the replacemant RR has multiple wires, just, as Biggles has done, splice the same colours together.

A point of interest, Honda RR units tend to fail more often on the smaller models with high revving engines. This suggests that there is a weakness in the units, for as I have said, over a certain RPM the RR has to lose excess AC voltage from the alternator in the form of heat, & obviously a CBR400 or 600 would have a higher average RPM than say a Fireblade or Blackbird.

Cheers.

[northwind]

Before I fitted the CBR600RR one I had a lengthy ask around, and didn't find a single failure of the reg/reg on that model... Loads of GSXRs, though, right up to the present day. Hardly an exhaustive check of course but it was encouraging.

I've got an SV one for a K2 for sale by the way ;)

[Spanner Man]

Before I fitted the CBR600RR one I had a lengthy ask around, and didn't find a single failure of the reg/reg on that model... Loads of GSXRs, though, right up to the present day. Hardly an exhaustive check of course but it was encouraging.

I've got an SV one for a K2 for sale by the way ;)

Afternoon all. & Windbag:D

I've changed two or three on CBR600RR's, but dozens on VFR800's & Fuel injected Blackbirds which use the same unit. Which somewhat contradicts my earlier statement regarding engine RPM being a contributory factor in a RR units life I know.
However these fail for a different reason or so it would seem.
Pete at Electrex had a theory that the excess current in the wiring loom, due to the injection control unit & the fuel pump etc was causing an electro magnetic spike to jump across from one part of the loom to another, thus causing current to enter the RR the wrong way.
It was actually for one of my customers VFR8's that had eaten two RR's that he developed a new unit fitted with clampdown diodes, that detect incoming current, & cut it off to prevent it wrecking the circuitry. It never ate another RR after the development one was fitted.
It may be that the 600RR has it's wiring routed in a different fashion, so as to keep the wires separate, & reduce the chance of spiking entering the loom elsewhere, hence the comparatively low failure rate.

GSXR units tend to fail due to the alternator wiring plug getting too hot & melting. More often than not the unit itself is fine. Just replace the plug, & hey presto!
Running another earth wire from the battery to the frame usually prevents this re-occurring.

Running another earth wire isn't a bad idea on any bike, for the Japs tend to run the earth terminal from the battery directly to the engine, therefore the battery earths through the engine mounts. Ok when the bike is new, but not so good when the mounting bolts have corroded a bit.

Cheers.

[northwind]

Yep, the VFRs and Blackbirds are legendary for it. I suppose they had to have at least one downside :)

[Spanner Man]

Yep, the VFRs and Blackbirds are legendary for it. I suppose they had to have at least one downside :)

Another downside apart from those Feckin horrible linked brakes that is!:D

[stooster]

Good morning.

It sounds like your alternator is ok, good show.

The RR unit from a 1995 CBR600 is considerably different to the one fitted to the later CBR's. Namely it doesn't have separate input & output leads coming out of it. There's a single 5 pin plug on the loom which plugs directly into it, also the live & the earth terminals are 10mm wide, & 'female' connectors are difficult to obtain in this size.
In my opinion Honda RR units are amongst the worst around, for over the years I have changed more units on Hondas than on all other makes combined. Some of which I suspect is due to deficiencies in the alternator design, which leads to the alternator spiking. I know Pete at Electrex winds his Honda alternators in a different fashion to the originals to help prevent this.

Your best bet would be to go for a RR unit from a GSXR, as they seem to be reasonably reliable, or go for a new Electrex unit. They are around £75 & have a 12 month warranty. their number is; 01491 682369.

An RR unit from a later CBR as Biggles has fitted may be ok, I tend to stay away from Honda RR's full stop! But as some of the RR problems on Hondas are attributable to the alternator there's nothing to suggest that they wont work reliably when fed by an alternator on a Suzuki.
If the replacemant RR has multiple wires, just, as Biggles has done, splice the same colours together.

A point of interest, Honda RR units tend to fail more often on the smaller models with high revving engines. This suggests that there is a weakness in the units, for as I have said, over a certain RPM the RR has to lose excess AC voltage from the alternator in the form of heat, & obviously a CBR400 or 600 would have a higher average RPM than say a Fireblade or Blackbird.

Cheers.

cheers for the help....should have read before i went to the breakers....the RR he had in was different like you say.....a single plug....i left it as i wasnt sure if it would work.....if i got the plug i could trim the wires and physically fit it easy enough....

but would it be suitable.....which models are suitable...will any 5 cable RR work....just getting ac in on the 3 wires and putting regulated dv out to the battery..or are some more complicated..

cheers again for your help

stu

[philipMac]

I got a 2nd hand one from SV spares for £35 -

Jaysus. 35stg???
Big window on that shop were there? I would bloody hope it works for that price. I think I payed less than 10 USD for my last one... $14 including shipping or something, which still seems ok.

[andywilson460]

Appears to be working at present, and has (probably - fingers crossed) solved the problem, so happy to pay it. - Will have to see over time though

[Spanner Man]

cheers for the help....should have read before i went to the breakers....the RR he had in was different like you say.....a single plug....i left it as i wasnt sure if it would work.....if i got the plug i could trim the wires and physically fit it easy enough....

but would it be suitable.....which models are suitable...will any 5 cable RR work....just getting ac in on the 3 wires and putting regulated dv out to the battery..or are some more complicated..

cheers again for your help

stu

Good morning.

If you could get the plug, the unit would work if it was wired in correctly. However, that particular unit is probably the most unreliable ever fitted to a Honda. When I had my place down south I used to keep two new Electrex ones on the shelf.
As I have stated, it may work reliably when fitted to a Suzuki.

Most five wire RR units will work, providing they're from a machine with a similar output alternator, & they're wired in correctly.

Cheers.

[chazzyb]

retested the battery and got 13.2 at idle then 12.9 at 5000rpm so yes it seems my RR has gone....


I just tested the regulated output on mine, having blamed my cheap battery last night. With main beam on at tickover I have 13.94V and this drops to 13.29V at 5K rpm. Is this the same regulator fault?

[stooster]

ok......finally the cbr 600 RR arrived....fitted it and now getting..

14.1 at idle
14.2 at 5k

i thought they would have been a bigger difference...but i would have though getting 14v would be fine so assume robert is my fathers brother...

cheers for all the help resolving this...special thanks to spanner man or id still have bike in bits;)

stu

[Spanner Man]

Morning all.

Good show Stooster, a pleasure to assist. It sounds like it's sorted, 14 volts average will do the job just fine, without the danger of overcharging.

Chazzyb Your regulator may be developing a fault, although it's not unusual to have the voltage drop a little as the RPM rises. Keep tabs on it, & if you get any sign of a flat battery (providing it's a good battery). You had better check the alternator & or change the RR.

Cheers.