Topic: regulator heats up so hot it burns my fingers!!!

[cadaver]

I'm working on a 1976 honda 550f ...long story short is that it has some bugs to work out ...I'm not getting any spark , i think that i can fix that ..but the problem that I'm stumped about is the regulator coil on the out side of it is getting so hot that it burns my fingers just trying to touch it ...and that happens fairly fast, is that normal? i haven't read anything with that same problem ..or I'm not seeing it ..any help would be very awsome...soon ill have pic of bike when i paint the tank and find side covers for it .

[scunny]

it shouldn't get that hot. check the fuse by the starter solenoid to make sure it's the correct current rating, then look for your fault

[Sporkfly]

Start cleaning connections. It's an old bike with old crummy connections. You'll see a huge improvement throughout if you get those contacts shiny or replaced with new.

Test your rectifier out as well, and +1 on checking your main fuse, mine had a 30a in there! PO chose to ignore the electrical problems rather than fix them.

[TomC]

Hi Cadaver
     "I'm working on a 1976 honda 550f ...long story short is that it has some bugs to work out ...I'm not getting any spark , i think that i can fix that ..but the problem that I'm stumped about is the regulator coil on the out side of it is getting so hot that it burns my fingers just trying to touch it ...and that happens fairly fast, is that normal? i haven't read anything with that same problem ..or I'm not seeing it ..any help would be very awsome...soon ill have pic of bike when i paint the tank and find side covers for it ."
     Buy regulator I think that you mean the Voltage Regulator. Does it have three wires going to it? One black, One white, & one green? If so it should be drawing about two and a third amps with the key on. The two amps current should go through a set of points and then through the field coil. The third of an amp should go through a resistor and a coil then to ground. If the Voltage Regulator is getting really hot this is not what is happening. Until you get the bike running just unplug the black wire. Make sure that the unpluged black wire does no ground on anything. Once your bike is running you will need to find out what is going on.
          TomC in Ohio

[cadaver]

thanks for the help all ....and from what you said tomc, i think that would realy help me out because the bike isnt running yet ...i had to throw in a diff motor since the other one wouldnt crank ... the wires on this bike is a mess..Im just thinking about bring it to a place and have them look it over ..but thats hard for me to do since i would like to do the hole bike project myself and say that i didnt bring it to a shop lol stuburn me .

[Sporkfly]

Heh, don't take it to a shop. This forum is a great resource and everybody is very helpful. I've more than once considered taking my bike to a shop for various things but decided not to. Keep working at it and you'll figure it out. My 550 was a non-runner when I got it and now it's purring like a kitten, just sorting out those electrical problems. I've almost got it sorted and I had limited mechanical knowledge going into this project and absolutely zip electrical knowledge. With some tinkering and persistence, I've got all my electrical working except for the charging system, but I've pinned down the problem and am working to sort it out. Read old threads, read the material in the technical library of the main page and you'll figure it out.

Keep an eye out for advice from TwoTired and HondaMan, they're both invaluable resources to this website. I promise you don't need to take it to a shop if you keep working at it. Keep us updated.

Cheers

[fmctm1sw]

Heh, don't take it to a shop. This forum is a great resource and everybody is very helpful. I've more than once considered taking my bike to a shop for various things but decided not to.

That is, if you can find a shop that will work on a vintage bike.  Local Honda shop won't touch mine (outside of changing a tire or the like)...

[TomC]

Hi Cadaver
     Professional mechanics HATE wiring! I down loaded The Honda Shop Manual for the CB500-550 from <www.honda4fun.com>. There are a number of changes is the wiring over the years so the factory manual is the only one to have as it has a number of wiring diagrams. If your bike has parts from more that one bike some adjustment of the wiring may be needed. If just the engine has been swapped you should be OK. Harbor Freight Tools has a multi meter on sale for $2.99. At that price I bought two. I have used one and it works fine. I also have a test light that I bought at a swapmeet for a buck. I like a test light when the question is "is there power here or not". Wiring is not that hard if you can organize how you go at it. I would start with one system. Say the ignition system. Start at one end of the system or the other. By end of the ignition system, one end would be the points, the other would be the battery. I would start at the points and look for 12 volts to ground at the points with the points open. If no voltage there go to the coils and check. Keep going back until you find 12 volts. Or start at the battery and go along the ignition system until there is no voltage. To be correct an electrical system does not have an end. I am defining the end as were the system connects to ground, engine case, frame, green wire. Checking all the grounds in particular the negative battery cable is a good place to start. Find some quite time for checking your wiring.
          TomC in Ohio

[Bodi]

The electromechanical relay regulator works by switching the alternator output on and off in three steps: full on, full off, and somewhere in between. Full on puts connects the black wire (ignition switched power) directly to the white (alternator field coil) wire. Full off grounds the white wire. In between connects a resistor between black and white, reducing the field coil current so that the alternator produces (hopefully) about the amount of power the lighting and ignition use. The coil visible on the underside of the regulator is this resistor. It is open and on the outside of the case because it gets quite hot, and being in the open air helps cool it.
Now generally the regulator actually spends very little time "in between"... so I think you probably have a dirty or burned contact in the regulator. Open the case - just undo the two smallish screws and the top lifts off. Look for any obvious problems like loose parts or melted stuff. If it seems OK, clean the contacts with a contact file or 600+ grit sandpaper, then flush any filings and/or sand out with brake cleaner spray or contact cleaning spray. The mechanism is adjustable to change the off-in between-on voltage settings but it is actually more complicated than it appears and adjustment attempts by neophytes usually cause a lot of grief.
There are a lot of electronic regulators available that elminate the wear prone contacts, Oregon Motorcycle Parts has drop-in modules for a bunch of cash http://www.oregonmotorcycleparts.com/vregulators.html or you can use a regulator from any number of automotive applications for a lot less $$$ but with a lot more fiddling with mounting and wiring.