Curvy starting problems - SV650.org

Goldy69 · 24-05-20, 05:51 PM

My bike was having an issue where it would crank but not turn over. Bought a new battery and it fixed this but the battery wouldn't charge so bought a new reg/rec and it still persisted. The battery voltage would decrease as you rev. Stator tests ok and reg/rec tests fine. Went for a ride yesterday and midway through the bikes clocks went weird and the bike died. Had someone jump start it and the bike would run but the dash was still being weird and sometimes the bike sounded like it was about to die. Rode home and the bike would not start again.

After charging battery again the bike now would idle but die as soon as you have any revs. However now the bike won't even start. Have checked spark and fuel. These are both fine.

I really have no idea what to check, it seems I fix something then another thing goes wrong lol

Biker Biggles · 25-05-20, 07:50 AM

You need to do a systematic diagnostic exercise as per one of the guides on this site. It is pointless and expensive to just change bits without knowing what is wrong and a faulty charge system will destroy a battery quite quickly. You say you checked the stator and it was OK but did you check its output? That would be a good place to start if other checks show the battery is not charging.

Goldy69 · 25-05-20, 08:59 AM

Yes the stator was outputting approx 80v AC at 5k rpm. But the fact that the bike will no longer start at all baffles me.

R1ffR4ff · 25-05-20, 09:08 AM

If you have a Workshop manual there's a troubleshooting section. It's quite often overlooked but can be a useful tool for diagnosing problems. As per other poster you need to go through a diagnostic regime.

If as you say it dies and you've checked the main things start on Electrical block connectors which can become corroded over time and cause no end of problems.

HTH

Goldy69 · 25-05-20, 09:01 PM

Thank you for your reply, here's an update.

Bike is now running i think the cutting out was due to a vacuum leak on the front carb as the rubber bung had a small crack on it.

The bike still has a charging issue though.

New battery, it sits at 12.2ish volts when idling, even less with the headlight on, decreases slightly when you rev.

Reg/rec outputting 14.8v on pos/neg, and the diodes tested correct. (This is also a new one)

Stator voltage at roughly 80v AC at 5k rpm. Has no continuity to ground. I did a resistance check and its getting 0.7/8 ohms on each pair of pins.

I went for a long ride, when i got back the battery was very low, in the 11V range. The bike still turned over but struggled.

R1ffR4ff · 26-05-20, 09:10 AM

You say you have tested the R/R but have you done the full diagnostic as per the manual. If the Rectifier part(Diode tests) of the R/R is failing it will let AC current through which can damage the battery and would show as low voltage across the battery

Just in case,

https://cx500.000webhostapp.com/Mosf...sfetUniRR.html

embee · 26-05-20, 04:11 PM

Quote:

Originally Posted by Goldy69

.....New battery, it sits at 12.2ish volts when idling, even less with the headlight on, decreases slightly when you rev.

Reg/rec outputting 14.8v on pos/neg, …...

I'm confused by this. The voltage you measure at the output of the reg/rec should be near as makes no difference the same as at the battery (assuming they are actually connected together).

I'd be looking carefully at the continuity of the connection between the reg/rec out and the battery itself. Have you had a really good look at the main 30A fuse in the starter relay, and checked the wiring and connectors between the reg/rec and the battery, and of course the battery terminals and fasteners?

Goldy69 · 26-05-20, 04:38 PM

Quote:

Originally Posted by embee

I'm confused by this. The voltage you measure at the output of the reg/rec should be near as makes no difference the same as at the battery (assuming they are actually connected together).

I'd be looking carefully at the continuity of the connection between the reg/rec out and the battery itself. Have you had a really good look at the main 30A fuse in the starter relay, and checked the wiring and connectors between the reg/rec and the battery, and of course the battery terminals and fasteners?

Yeah I did think it should be the same, it seems that the new reg/rec must be faulty as on the original at idle u was getting mid 13v and on the new one it was in the low 12s. I decided to wire the reg/rec straight to the battery as it was recommended in the forum's. Its now getting above 14v at idle but does still drop slightly with revs (however this might be normal?)

I will double check the wires from the reg but didn't see anything abnormal.

SV650rules · 26-05-20, 05:17 PM

Quote:

Originally Posted by Goldy69

Yeah I did think it should be the same, it seems that the new reg/rec must be faulty as on the original at idle u was getting mid 13v and on the new one it was in the low 12s. I decided to wire the reg/rec straight to the battery as it was recommended in the forum's. Its now getting above 14v at idle but does still drop slightly with revs (however this might be normal?)

I will double check the wires from the reg but didn't see anything abnormal.

If you connected RR direct to battery and got higher voltage than you got before that confirms embee post that there is a high resistance joint between RR and battery when it is connected to normal wiring. As current flows from RR to battery some of the voltage will be dropped across the bad joint and never reach battery terminals...

Goldy69 · 26-05-20, 05:20 PM

Quote:

Originally Posted by SV650rules

If you connected RR direct to battery and got higher voltage than you got before that confirms embee post that there is a high resistance joint between RR and battery when it is connected to normal wiring. As current flows from RR to battery some of the voltage will be dropped across the bad joint and never reach battery terminals...

Yes I will investigate this. Do you think this could effect how the bike runs at all?

24-05-20, 05:51 PM	#1
Goldy69 Junior Member Join Date: May 2019 Posts: 11	Curvy starting problems My bike was having an issue where it would crank but not turn over. Bought a new battery and it fixed this but the battery wouldn't charge so bought a new reg/rec and it still persisted. The battery voltage would decrease as you rev. Stator tests ok and reg/rec tests fine. Went for a ride yesterday and midway through the bikes clocks went weird and the bike died. Had someone jump start it and the bike would run but the dash was still being weird and sometimes the bike sounded like it was about to die. Rode home and the bike would not start again. After charging battery again the bike now would idle but die as soon as you have any revs. However now the bike won't even start. Have checked spark and fuel. These are both fine. I really have no idea what to check, it seems I fix something then another thing goes wrong lol

25-05-20, 07:50 AM	#2
Biker Biggles Member Mega Poster Join Date: Jan 2005 Location: Barnet Herts Posts: 5,068	Re: Curvy starting problems You need to do a systematic diagnostic exercise as per one of the guides on this site. It is pointless and expensive to just change bits without knowing what is wrong and a faulty charge system will destroy a battery quite quickly. You say you checked the stator and it was OK but did you check its output? That would be a good place to start if other checks show the battery is not charging. __________________ On a clear day we stand there and look further than the ordinary eye can see.

25-05-20, 08:59 AM	#3
Goldy69 Junior Member Join Date: May 2019 Posts: 11	Re: Curvy starting problems Yes the stator was outputting approx 80v AC at 5k rpm. But the fact that the bike will no longer start at all baffles me.

25-05-20, 09:08 AM	#4
R1ffR4ff Member Mega Poster Join Date: Feb 2017 Location: JAMOADR(1999 Curvy) 36,000 miles Posts: 1,429	Re: Curvy starting problems If you have a Workshop manual there's a troubleshooting section. It's quite often overlooked but can be a useful tool for diagnosing problems. As per other poster you need to go through a diagnostic regime. If as you say it dies and you've checked the main things start on Electrical block connectors which can become corroded over time and cause no end of problems. HTH __________________ "Stultus est sicut stultus facit"

25-05-20, 09:01 PM	#5
Goldy69 Junior Member Join Date: May 2019 Posts: 11	Re: Curvy charging problems Thank you for your reply, here's an update. Bike is now running i think the cutting out was due to a vacuum leak on the front carb as the rubber bung had a small crack on it. The bike still has a charging issue though. New battery, it sits at 12.2ish volts when idling, even less with the headlight on, decreases slightly when you rev. Reg/rec outputting 14.8v on pos/neg, and the diodes tested correct. (This is also a new one) Stator voltage at roughly 80v AC at 5k rpm. Has no continuity to ground. I did a resistance check and its getting 0.7/8 ohms on each pair of pins. I went for a long ride, when i got back the battery was very low, in the 11V range. The bike still turned over but struggled.

26-05-20, 09:10 AM	#6
R1ffR4ff Member Mega Poster Join Date: Feb 2017 Location: JAMOADR(1999 Curvy) 36,000 miles Posts: 1,429	Re: Curvy starting problems You say you have tested the R/R but have you done the full diagnostic as per the manual. If the Rectifier part(Diode tests) of the R/R is failing it will let AC current through which can damage the battery and would show as low voltage across the battery Just in case, https://cx500.000webhostapp.com/Mosf...sfetUniRR.html __________________ "Stultus est sicut stultus facit"

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