Battery-Stator-Reg/Rec

200 vfr800- and I suck at electrical

Replaced Battery, replaced Stator, replaced Reg/Rec.

Battery 12.7 at start. Never dips below 12v at idle or rpm but never gets up to 13v +. Highest is around 12.8v. I'm I ok?

I did check output from Stator pin to pin. All around 17.

Glenn in San Diego

 

I'd be concerned at that voltage. Honda calls for 13.5-14.5V when running at 5000rpm. You will know soon enough if your battery starts going flat on you.
The stator voltage is questionable; you need to test AC volts and should see over 50V from pin to pin with the engine running at 5000rpm.

 

Thanks Terry - I just retested Stator AC volts. I'm at 17v at idle and get up to 48v at higher rpm pin to pin.

 

the usual high-rpm AC voltage is closer to 55, seems that yours may be undercharging. it is if you dont see between thirteen point 5 and fourteen point 5 across the battery terminals at 5OOO rpm.

inspect the connections between r/r and stator [three yellow wires] for signs of overheating, also wires going to starter solenoid.

 

Thanks guys... just re-tested with help from a bud to hold throttle. I did get into the 50 to 60v range at 5000. Still under 13v at battery when running. No visible burning with wires. Battery was fresh today it was 12.4 to 12.7 standing. I'll trickle charge just to eliminate that possibility.

 

signs point to a bad r/r

 

r/r seems right. But unless you fix the underlying issue, it'll just creep back in...usually in the rain...far from home...in the dark.

 

I'm inlcined to agree with my furry friend. If the alternator checks out but there's not enough voltage at the battery, the RR is the likely culprit.

I have attached a fault finding diagram that might be of some use.

 

Looks like regulator.... visit Roadster Cycle and upgrade to a modern mofset and bypass all those stock wiring paths.......

 

New Stator is putting out the 50 to 60v at 5000. New Reg/Rec passed resistance test. New Battery. (Old Stator was visibly burnt).

Still only 12v to 12.8 at battery. I held on to original Reg/Rec. Tried it just to compare. Both old and new Reg/Rec have same under 13v at battery, identical readings. Quick ride enough to get it up to temperature. Battery is drained.

 

What reg did you use? OEM? New or used?
If OEM, you better check all connections, including back to the starter relay and ensure clean and tight.

 

I swapped out Reg that has been on the bike since purchased in 2006. No marking on it not sure if it was the original. Hat it tested at a shop, they said it was good but couldn't fully test?

Decided to switch out with new aftermarket Reg. Still under 13v when running either one.

 

If the two RRs give the same result then either both are toast or your problem lies elsewhere. Did you try the diode tests in the fault finding diagram that I posted earlier?

The charging circuit is pretty simple, I'd suggest checking the continuity of the various wires from point to point, and especially things like earth connections are clean on the frame.

I know from personal experience that you will get 30-45 minutes of normal running out of a charged battery with no re-charging happening, but you will start to see bizare behaviour in the instruments when the voltage gets very low.

 

I feel your pain, as four hours ago I was running alongside a VFR in a parking lot in 2nd gear and slipping the clutch. I got it fired and eventually home. I'm not going to go in depth with my issues for your thread, but for reasons I'm troubleshooting with I'm digging into the wiring harness. There's a little more going on than that simplified diagram above. The troubleshooting flow chart in the service manual says to check DC voltage directly at the regulator connector if regulated voltage isn't meeting for the battery check. One of the possible faults is "loose or poor contacts of related terminal". There's a bunch of opportunities for that between the regulator and the battery.

 

This is today at operating temperature and 5K RPM. I charged the battery back up and the same stator, regulator are in place. I got back from two hours of mixed riding, everything seems stable. I bypassed the DC connector on the VFR's harness. Regulator is going directly to battery terminals.
https://www.vfrdiscussion.com/index.php?/forums/topic/88542-charging-system-performance-upgrade/