Hi fellows. It is a 99 Magna VF750. 10,500 miles on her.
I keep it constantly hooked-up to a trickle charger. Ride the bike twice a month, or aprox 50 miles/month.
averytime I ride, I disconnect the charger, and the bike fires right up. A little choke, warm up, and she is fine.
Ride 10 miles, stop for gas, remove key, fill her up, and try to start again....and here is the issue.
The started runs "as if" there is not enough juice going to it. can't start. almost running down the battery.
Put her on 2nd, and roll and release clutch....couple of tries and she runs. this has happened twice within the last month.
Removed seat and measured 12.4 V directly from the battery terminals.
Is the battery? Is the alternator not charging the Batt during the 10 mile run? Is it the starter?
what do you thing guys? thanks a lot.
I would be most suspicious of the starter. I'm guessing it will eventually start if you give it time to cool down. For example, you go somewhere for lunch and it starts up after siting for 30 minutes or more. Keep a volt meter handy and check the voltage on one of these occasions when it won't start. If you're showing 12-14 volts, that points toward the starter. If possible, ride it around then come back to your place and shut it down. If the problem occurs, test the starter by jumping from what you know is a good battery, say the one in your car. If it starts with a jump, then that points back to the battery.
Before you replace the starter or battery, check the connections to them. Could be as simple as a corroded ground.
If the starter is turning over it's probably not the starter how old is the battery? Does the trickle charger charge it all the time or does it turn off when it reaches full charge if its charging all the time the battery could be over charging which is not good for it. Next time it happens try jumping it from a good battery if it starts you have your answer.
ok guys,
I will check the ground and battery connections at the starter first, and let you know. Is it safe to use jumpers from a 750Amps car battery to the starter directly? I assume before doing that I have to disconnect the starter from the Bike's battery correct? thanks.
It's ok, I usually do not start the car though...
Clean the connections at the battery & cables.
There is also connections from the hot side of the battery to the starter relay (under left side panel), and from the relay going toward the starter, check all those connections as well...
I would suspect the RR. Since you leave it on the charger, initial startup is fine, but after riding the battery depletes from not getting enough charge from the RR, and then its slow, to no, start time. Check the battery with your multimeter with the engine running at about 2500-3000 rpm, if the battery isn't in the 13.5-14.5v range your RR is probably at fault. I suspect you will see a <13v reading. Note that a discharged battery can still read normal voltage when not running, but cannot deliver enough amps under load.
Also note that it you do need a starter, I have a used one that would go for much cheaper then new. I bought it a few years ago to diag a different problem, but ended up not needing it. But, as I said, I don't think it's your starter.
Thanks Lurkin.
I removed the battery and took it to a shop and they plugged it into a device that applies load to it, and the voltages were very low under load...The battery was 5 years old. So, I purchased a new one, but have not installed it yet as the bike is not near me.
However, please tell me what the RR is. is it a relay? what makes you think it is the RR? I agree that the problem is not the starter as it sounds and works well if the charge to it is correct. Thanks.
never mind responding what a R/R is. I searched the site and found plenty of info on this device.
Did the group reach a final conclusion on how to "remedy" this heat build up problem?
Was relocating the RR, or diverting fresh air onto it, or extracting hot air the solution? Or are we still working on a solution?
thanks.
Someone on this site developed a bracket to move the RR to the right side of the bike..
I build my own set up to do the same...
I still had an aftermarket RR fail...
I think it helps, but short of putting a fan on the RR, I Think it is likely to still be an issue...
What has been observed is that bikes 2000 and older tend to have RR failure relatively early (less miles) than the later bikes.
I've been through 3 regulators, two in the original location and one in the new location...
As is the case with many complex problems, there is no clear consensus on this issue. I have two 3rd gen Magnas. One of them has a relocated R/R and the other still has the original location under the battery box. I have not experienced an issue with either, so cannot conclude what is best. At least one aftermarket replacement uses power MOSFET's for the shunt devices instead of SCR's. One would expect less heat build-up with the lower "on" voltage of the MOSFETs , but I have no data regarding reliability of these devices.
It would be interesting to know what extra accessories are on bikes that experience high failure rates of this component. Does high current load contribute?
Bottom line, it is pretty much a crapshoot, in my view. You have no doubt already read how to test to see if yours works. If it does, as I suspect, then be happy with your new battery and the R/R you have until it dies -- if it ever does.
The Honda Magna is a very reliable machine, and it seems to me the R/R is the component most likely to fail. Not bad for 18 year old bikes...
Thanks Lawrence, and thanks again for taking my call the other day. regards.
In case you haven't figured it out...
Lawrence is our resident Electronic genius...
(http://i39.tinypic.com/30b0oap.jpg)
Just a couple more comments. I would still check your regulator-rectifier (RR) once you get the new battery in. While it may just be the battery going bad, you RR could still be causing it to go bad. The RR can fail low or high (my terms, you would need to get the resident electrical guru to chip in the right terms).
If the RR fails low, no/little current gets to the battery and it slowly dies, or it just gets minimally charged, then it sits for a while and the battery goes flat. Too many cycles of this can cause the battery to fail. Most RR failures that I've heard/seen are this mode.
If the RR fails high, the RR basically sends all/most of the current to the battery and the battery boils/expands/expodes(maybe...). Note that this can also cause electrical components to fail due to the high current. I've seen fewer reports of this mode, but it can cause much more damage then the low mode.
A simple multimeter check with the engine running and some rpms to it will tell you the story here though.
Right on, Lurkin. Hang a voltmeter across the battery, rev 'er up to 3000+ rpm, and read the voltage. If below 12.6 volts, indicates a "low" (undercharge) failure, and above 16 volts a "high" (overcharge) failure.
Odds are, he would have noticed the effects of a "high" failure -- swollen battery, fluid running over and eating away at connections, metal parts below, etc. I have seen one of these in person, during a MOOTMAG in OK, on Felicia's bike, as I recall. Not pretty.
Quote from: lragan on December 09, 2013, 10:28:03 AM
Right on, Lurkin. Hang a voltmeter across the battery, rev 'er up to 3000+ rpm, and read the voltage. If below 12.6 volts, indicates a "low" (undercharge) failure, and above 16 volts a "high" (overcharge) failure.
Odds are, he would have noticed the effects of a "high" failure -- swollen battery, fluid running over and eating away at connections, metal parts below, etc. I have seen one of these in person, during a MOOTMAG in OK, on Felicia's bike, as I recall. Not pretty.
Mine died on that same trip. You help me load it on Charles' trailer IIRC. I noticed a smell like rotten eggs beginning about 24 hours before the final melt down. Unfortunately, I didn't recognize the symptom for what it was.
Guy, I remember helping load yours, but was asleep on the seat, I suppose, when it died, so did not observe the failure until after the fact -- at which time it had cooled down, and the smell of Hades had subsided. That trip was my introduction to the R/R issue, but boy, it got my attention!
Quote from: lragan on December 09, 2013, 04:33:30 PM
Guy, I remember helping load yours, but was asleep on the seat, I suppose, when it died, so did not observe the failure until after the fact -- at which time it had cooled down, and the smell of Hades had subsided. That trip was my introduction to the R/R issue, but boy, it got my attention!
It got mine too. Two (2) R/R failures on one trip seem like something we ought to pay attention too. I was really great to have all the MOOT folks around to bail me out. A special thanks to you, Charles, and the others who helped load my Maggie up and haul her home.
I bought a used RR (It actually came out of an ATV, and I had to splice a ground wire.) I haven't had a problem since.
Here's a link to my post on my RR replacement.
http://www.magnaownersoftexas.com/forums/index.php/topic,5021.msg48120.html#msg48120 (http://www.magnaownersoftexas.com/forums/index.php/topic,5021.msg48120.html#msg48120)
food for thought: I bought my magna with a burnt up r/r. I purchased a new one on ebay for half the price and didn't notice the positive and negative pins were backwards and it kept popping the main fuse. make sure your pins are pinned in the proper terminal lol. cost me two hours before I solved it lol. :grin:
Well, at least fuses are cheaper than Regulator/Rectifier modules...
that is true lol, but i will tell you my stress level and frustation level was just as bad lol.