Hot day and volt meter reading

[Guest Ken8143]

Yesterday I traveled from a ride in and the day was hot hot hot, and to make it even worse got caught in horrific traffic back jam due to accidents or what ever. I noted my bike was getting on the hot side of things so cut engine off whenever I could.

 

Also noted the volt meter stayed at just above 12 volts at higher rpm rather than at 14 as usual. This morning it pops right back up to 14.

 

Any reason or explanation for this? I already cleaned the wire connectors from stator and put dialectric grease on it some time ago.

[starman]

I had the same problem yesterday on my roadstar. Ihpoe it is heat related.Every thing seems ok this morning

[dingy]

The extended use of brakes will help draw down the voltage on the battery on MKII bikes.

 

This is due to the electric anti dive units. They draw quite a bit of current.

 

The anti dive valves are actuated whenever the front or rear brake is engaged. This would happen when sitting in traffic for periods of time.

 

When I rebuilt my bike this winter, I made a modification to the wiring harness to disable the anti dive units when the rear brake is used. I have de-linked brakes now, so the rear brake does not need to engage anti dives. When I am stopped in traffic, I can use just the rear brake to maintain bike at stopped position.

 

Not an easy modification though, it required opening up the wiring harness casing to insert a diode at the required point.

 

Gary

Edited July 19, 2010 by dingy
clarified reason for wiring mod

[MiCarl]

The extended use of brakes will help draw down the voltage on the battery on MKII bikes.

 

This is due to the electric anti dive units. They draw quite a bit of current.

 

The anti dive valves are actuated whenever the front or rear brake is engaged. This would happen when sitting in traffic for periods of time.

 

When I rebuilt my bike this winter, I made a modification to the wiring harness to disable the anti dive units when the rear brake is used. I have de-linked brakes now, so the rear brake does not need to engage anti dives. Not an easy modification though, it required opening up the wiring harness casing to insert a diode at the required point.

 

Gary

 

Plus the cooling fan was probably running too. Not enough power to keep up.

 

I still wouldn't turn off the bike though. You might not have enough juice to restart.

[Snaggletooth]

 

Yep....between the two 1157 bulbs in the brake light and the cooling fan kicking in there is a noticable drop in the voltage. When I get hung up in the city stop and go traffic on a hot day mine will drop down to 13.2 with the fan and brake lights on. Get rolling again and it's back up to 14.3. The electric anti dives will add to that drop for sure.

 

I've got the uprade stator in mine to so it was worse before I changed that out.

 

As said, I'd keep the bike running also. If the battery is getting a low charge and the engine is hot, and the engine temp will climb a bit when you shut it down, the bike will actually have a harder time starting again. Let the fan do it's job on cooling and save the drain on the battery from doing a hot start.

 

Mike

[Condor]

If your battery is an OEM type wet cell there's not a whole lot of amps in reserve. With the fan on, hitting the brake lights, head light, and runing lights on, it put's a hell of a draw on the spare amps. Plus if you're listening to a tape, it'll be close to fatal. Especially when turning off the motor, and all those things still sucking amps. And turning off the motor will stop the coolant circulation causing things to get even hotter...not cooler. The temp guage will climb very close to the red zone, but the fan should kick in about that time, and it'll fall back down a couple of needle widths. But ya gotta keep the coolant circulating by keeping the engine running. You might also invest in a DEKA AGM battery from Bohanon....

[Flyinfool]

I have noticed that the volt meter on my bike reads high when the temp gets up near the red, it does drop a bit with the fan.

The dash meter does not have any marking to read an actual voltage but it was running up to about 1/8 from the top of the scale.

I checked it with my digital multi-meter and it was at 13.2 at idle and the fan running and 13.8 at 2500. So I am just assuming that the dash meter is being affected by the heat.

My voltages at all engine speeds are up since I went to the 35W headlight.

[jasonm.]

I have found the meter on the dash reads a bit low(calibration)...from my perspective. The fan draws about 5 amps...brake lights another 4 amps....and hell...you're idling. can you say discharge of battery? Always put the battery on a trickle charger if you can after a run like you had. Also the new AGM sealed batteries are great. I have one that is 8 years old. And it's still great.

Edited July 22, 2010 by jasonm.

[Sylvester]

Run LEDs and cut out most of the drain. With two 55watt pass lights and a headlight my RSMV is at 13 volts all the time (hot or cold).

 

[MiCarl]

Run LEDs and cut out most of the drain. With two 55watt pass lights and a headlight my RSMV is at 13 volts all the time (hot or cold).

 

 

He's got a MKII 1st gen. Electric anti-dives. Real power hogs. My pair of 55W driving lights don't move the meter at all, hit the brakes and it heads for the floor.

[6m459]

I have '84's, so of course don't have electric anti dives but you never know, I might have a younger one join the fleet some time:innocent:. I have to admit that am surprised to hear that the electric anti dives are full time current hogs.

 

These bikes are so well engineered generally, that it surprises me that the anti dives aren't de-energized again a short time after the brakes are applied. Much like the fuel pump is when the ignition is first switched on.

 

If this really is the case, I'd be tempted to modify mine (if and when) so that they are only energized for say 20 seconds per brake application. That should be long enough to take care of sudden stops but short enough to spare the charging system a coronary in traffic.

 

Have I missed something?

 

Brian H.

[GeorgeS]

Would be wise to Charge the battery, Check the---- " No Load Voltage "

 

Put charger on it for several hours, the let sit, and re-check the No Load Voltage.

 

Use a Real Charger, not a trickle charger.

[Guest tx2sturgis]

So I learned something new: Some of the 1st gens have electric anti-dives, and these apparently draw a fair amount of current, I'm assuming they activate on the closure of the brake light circuits.

 

Interesting, but is it possible to put in progressive rate front springs or cartridge forks (or cartridge emulators) and get pretty much the same result? Then you could deactivate or remove the anti-dive system...am I right?

 

Or is that system that good, or that hard to remove...making it not worth the trouble?

 

Hey I'm just askin'....

 

[dingy]

So I learned something new: Some of the 1st gens have electric anti-dives, and these apparently draw a fair amount of current, I'm assuming they activate on the closure of the brake light circuits.

 

Interesting, but is it possible to put in progressive rate front springs or cartridge forks (or cartridge emulators) and get pretty much the same result? Then you could deactivate or remove the anti-dive system...am I right?

 

Or is that system that good, or that hard to remove...making it not worth the trouble?

 

Hey I'm just askin'....

 

 

Someone on here did this to their bike after installing progressives

 

I believe they made a plate that covered the holes in the forks after removing the anti dives.

 

Gary

[MiCarl]

 

I believe they made a plate that covered the holes in the forks after removing the anti dives.

 

Gary

 

That would have the effect of the anti dive being in the "on" state. In normal operation oil flows through those holes and through the anti dive unit. When the anti dive activates the passage is closed off and oil can only move if it overcomes the spring pressure on the oil lock. Blocking the holes would result in a very harsh ride.

 

Disabling MKII anti dives is simple. Just unplug them.

[jasonm.]

He's got a MKII 1st gen. Electric anti-dives. Real power hogs. My pair of 55W driving lights don't move the meter at all, hit the brakes and it heads for the floor.

The anti-dive is just a solenoid...aka electromechanical switch. They really don't draw much miore than 1 amp. Your tail brakes light draw much more. But I have my anti-dive on a switch. Only use it on the interstates.