Honda CBR 600F3 Rectifier Problems

[Breadsnapper]

Hi everyone, hope all's well. Right then riding for about one and half hours stopped for a brew. Come to start bike up and it turned over very slow as if the battery was flat. After 3 attempts the battery was completely flat. Anyway bumped started it and ran fine for 10 mins then I noticed that the Speedo was all over the place. Couple of minutes later the bike died. Started with a bump again then ran fine for the 30 minute ride home.

Switched engine off and it was dead again.

The wiring connector to the rectifier looks like it's been getting very hot as it's scorched. Particularly the middle of pin the 3 yellow wires. The rectifier itself.look like it's been getting hot too and the plastic shroud again around the middle pin is a bit melted.

Before I can do any checks I am charging the battery which seems to be charging ok for now 11.9 V .081 Amps.

So what tests do I need to do to establish the fault.

Cheers in advance Dave

[fastbob]

I know that they say " You get what you pay for " but sometimes you really do wonder .

[James in Brum]

[mention]Stu[/mention] pointed in the right direction to test my stator cool when my ref/rev was knackered. Having spent out on a proper grand ref Rev I then discovered it had not resolved the problem. There is a topic on here of me being talked through testing it. That way you only have to replace the actually knackered part

[Tiggie]

https://www.themotorbikeforum.co.uk/viewtopic.php?f=5&t=72075

[Breadsnapper]

Thanks for the replies everyone.

Dave

[WD-40]

Here's my understanding of it. It's a bit of a long winded explanation, might sound hard but it's an easy enough to do. You're basically measuring the DC voltage across the battery when the bike is running. Then measuring the DC voltage out of the Reg/Rec. Then measuring the AC voltage into the Reg/Rec. Then measuring for high resistance in the stator. Then checking if the stator is short to ground. You can have a fault in the wiring, the Reg/Rec, the stator or both the Reg/Rec and the stator. To accurately test the Reg/Rec the AC voltage going into it has to be good so the alternator has to be working correctly, so the stator in the alternator has to be good. You can't diagnose the Reg/Rec until the AC voltage going into it is good.

The procedure is. Start the bike. Measure the voltage across the battery. You should see around 13V DC at idle rising to around 15V when you rev the engine. That would show that the charging system is working properly. If you see less than that or more than that you have a problem with the charging system.

If you have a problem next measure the voltage at the Reg/Rec. There's usually five wires at the Reg/Rec. Three wires will be the same colour, they're the AC wires coming from the stator in the alternator, going to the Reg/Rec. They're the input wires going into the Reg/Rec. AC goes into the Reg/Rec and DC comes out to charge the battery and power the rest of the bike. So the other two wires at the Reg/Rec are the DC output going from the Reg/Rec to the battery. One wire which is usually red goes to battery positive. The other wire which is usually green goes to battery negative.

With your meter still on DC measure the voltage across the red and the green wires. That will tell you the DC output that is coming out of the Reg/Rec. You should see what you saw across the battery. If you see something different to what you saw across the battery it would mean there's a wiring problem between the Reg/Rec and the battery which is unlikely. Most likely you will see the same voltage as was on the battery. Good would be around 13V rising to around 15V when you rev the engine.

If the DC voltage coming out of the Reg/Rec is too low. Switch your meter to AC and measure the AC voltage on the three wires that are the same colour going into the Reg/Rec. You have to measure every pair of combinations of the three wires because they're all connected. The voltages across all connection pairs should be roughly the same. About 20V AC at idle rising to about 70V AC at 6000RPM but those numbers are just a guess. All bikes are different so check your manual for the exact number. If the voltage is low across any connection pairs you probably have a damaged stator winding and you will need a new stator.

You can confirm the stator is damaged by turning the bike off and doing a resistance test between the connection pairs. Set your meter to resistance and measure the resistance of every combination of the three wires. Your manual will give you the spec of what the resistance should be. If one pair of connections is higher resistance than the others it shows that one of the phases of the stator is burned and you need a new stator. If you take the engine cover off to check the stator you will probably see a burned or discoloured area on the stator.

You should also test if the stator is short to ground. It could look ok with no signs of burning but still be short to ground. That happens if the insulation coating on the stator has failed and the stator is touching the rest of the bike which it shouldn't do. It should be isolated from the rest of the bike. You test for a short to ground by measuring the resistance between each of the three wires that are the same colour and the green wire which is ground. It should show infinite resistance on the meter which shows that there is no connection between the stator and ground. Usually the meter shows OL or something like that. If a resistance reading comes up on the meter it shows there is a short to ground and you need a new stator. The voltage tests with the bike running are probably the best to do because sometimes electrical faults only show up with the bike running when things get hot and expand.

If you find that the stator is faulty replace it and do the tests again. That will confirm whether the Reg/Rec is faulty or not. If it is faulty and you don't replace it it could burn out your new stator and you're back to square one so make sure you test it after you install the new stator.

This guy has a good video on testing the charging system. He starts taking measurements at around 20 minute

You should check your workshop manual too for the proper procedure and the spec on what values to expect.

[skyrider]

I know that they say " You get what you pay for " but sometimes you really do wonder .

i would go for the £11.98 one

[fastbob]

I know that they say " You get what you pay for " but sometimes you really do wonder .

i would go for the £11.98 one

 

Save up to 8% with multi buy . Get ten , flog them for £89.99 and earn yourself a nice little holiday .

[skyrider]

that sounds good

[Breadsnapper]

Right, done some tests. Firstly battery is low charged and holding charge. Of I set my multi meter to ohm and test from each of the 3 pins that would have the the yellow wires connected to earth I get two that are OL and one that is 3k ohms. Ammi right in thinking that I shod.aee OL on all 3? And that this would identify as it being the rectifier? Also the battery is showing 13 volts when the bike is idling. Is this correct?

Cheers

Dave

[WD-40]

With the connector at the Reg/Rec unplugged yellow to green should all be OL when checking resistance. There should be no connection between yellow and green.

Yellow to yellow should show resistance. The spec for what the resistance should be is in your manual.

13V on the battery at idle is good. If it's 13V rising to around 15V when you rev it to 6000RPM it means the charging system is working.

If you don't know how the charging system works and the other video is too long have a look at this one.

[Breadsnapper]

Cheers[mention]WD-40[/mention] I will give that ago like I said one yellow to 3 gives a reading so that would indicate a fault if I understand you correctly

Dave

[WD-40]

Yeah if there's resistance between yellow and green with the connector unplugged from the Reg/Rec, that would show that the stator is touching ground which it shouldn't. Try taking the cover off the engine where the stator is and have a look at the stator. If one of the stator windings is burned it needs to be replaced.

[Breadsnapper]

Sorry if I've confused you but that is what I am seeing at the rectifier with it unplugged.

Dave

[WD-40]

Yeah you did that test correctly if you unplugged the connector from the Reg/Rec. The resistances means the stator is touching ground which it shouldn't. It should be separated from ground by the insulation that's painted over it. What happens is if the stator gets too hot it burns the insulation coating and that causes the stator to touch ground and that's a short circuit.

[Breadsnapper]

Must be me but this is all so confusing. If the stator was bad then wouldn't the bike run poorly. As soon as I start it it is ok. As in no misfires, light all work etc. Surely if there wasn't enough current from the stator then the bike would.run poorly. Even when the battery was completely flat it bump started and ran fine.

Dave

[WD-40]

It'll run ok off the battery for a while then as the battery goes flat the problems show up. I'm just going on what you've said. You said there is resistance between yellow and green. That's a short between the stator and ground.

Try starting the bike and measure the voltage at the battery. If it's 13V at idle and rises to around 15V when you rev it to 6000RPM the charging system is working

[WD-40]

I've explained it as best as I can, as simply as I can. If you're confused maybe wait for someone else and they can explain it in a way that makes sense to you.

[Breadsnapper]

I've explained it as best as I can, as simply as I can. If you're confused maybe wait for someone else and they can explain it in a way that makes sense to you.

 

Yeah cheers. I appreciate your patience. I was looking at it from resistance so the two open circuits I have from the rectifier were right and the one that shows there is resistance is faulty. What I need to do is run voltage across the circuit on the rectifier using the diode function on my meter. And test the stator which I haven't done. Think it's finally sunk in.

Again cheers

Dave.

[James in Brum]

My bike ran right up until it didn’t. No signs of failing or running badly just ran out of electric and wouldn’t get more. Plug battery into something and it runs, disconnect the supply and it runs out of Battery again.

[Breadsnapper]

Cheers for all the replies it was a faulty rectifier. Particular thanks to [mention]WD-40[/mention] The link to the video that was posted is excellent, it is long but excellent and gives you the info in a very usable, understandable way.

Cheers

Dave.

[WD-40]

Nice one. I had a F3. Was a brilliant bike. I loved it. I'd get one again or maybe the newer model RR