Author Topic: My '78 550k died while I was riding it. Walked it home. (Read 3559 times)

egar · « **on:** December 02, 2005, 11:06:04 AM »

I took the day off to Christmas shop and ride at the same time. Keeps the wife happy knowing I'm spending money on her, even though it is really an excuse to ride. I took one last swing around the block on the way home (because I really was enjoying myself), and the bike just died. No dummy lights. No nothing. I checked the battery and it appears to be OK. My fuses, including the 15A main fuse look fine. I took each one out and inspected it. It's obviously an electrical problem due to the fact that there are no lights on whatsoever - no neutral, oil, headlight or taillight. Any suggestions? I haven't needed help since August. What to do?

ohiocaferacer · « **Reply #1 on:** December 02, 2005, 11:18:33 AM »

Check the main ground coming off the battery neg terminal, where it connects to the frame. Should be down at the rear motor mounts.

Sometimes these get really corroided(sp?)......

Greg
www.OHIOCAFERACERS.com

egar · « **Reply #2 on:** December 02, 2005, 11:21:49 AM »

Thanks, Ohio,
I will go do that right now.

bryanj · « **Reply #3 on:** December 02, 2005, 11:22:58 AM »

Check for 12v +ve at all the black wires you can find. The ignition switches are notorious on this modle and if you are lucky you can find just the electrical block part as either a genuine or emgo aftermarket part. Somewhere i have a couple of the emgo ones but at the moment its pure guesswork as to where

egar · « **Reply #4 on:** December 02, 2005, 11:54:11 AM »

Bryan J,
I'm sort of dense when it comes to electrical malfunctions. Are you saying I should follow all of the black wire and check for a positive charge. Also, it sounds like you're saying I should consider a faulty ignition switch? Could you dumb it down for me? Thanks for your time.
I've been reading on old posts that the ignition switch can simply die on these bikes. Maybe I should order a new one.

apormarkos · « **Reply #5 on:** December 02, 2005, 12:43:10 PM »

My buddy's bike died just like that and it turned out to be the ignition switch. He had a pound of keys hanging from the keychain, I think that's what did it in. We could tell it was the switch right off the bat because a little wiggling of the key in the ignition got the dummy lights to come on intermittently. Good luck, and maybe it's just a grounding problem...
apor

egar · « **Reply #6 on:** December 02, 2005, 12:50:38 PM »

Apor,
The ground on my battery is not corroded or loose. Its connection to the frame is tight and corrosion free as well. I've got this feeling it is the ignition switch. I may order a new one from Dennis Kirk. The bike came with only one key anyway, and it is a bit wiggly. I never had a problem before today, but the bike is almost 28 years old.

TwoTired · « **Reply #7 on:** December 02, 2005, 01:03:50 PM »

Try another 15 amp main fuse.
I don't care if it looks good. It has to actually be good for proper function. If the fuse clips aren't bright shiny white gold color they are corroded. The corrosion causes resitance, resitance causes heat and actually melts fuses where you can't see the break. All without an actual overcurrent condition. Also, check the back of the fuse block solder connections. If you see any melted plastic around the fuse clips, you know you have a heating problem.

Could also be the ignition switch, wire connection, etc.

Gotta poke around some, and find out where connections are gone.

Cheers,

egar · « **Reply #8 on:** December 02, 2005, 01:14:14 PM »

The clips are in nice shape, but I think I will replace the 15 regardless. When the bike died, my first thought was "fuse", especially given that none of the dummy lights came on when it died. I will also check the other things as well. I'll probably order the new switch just for peace of mind.

ElCheapo · « **Reply #9 on:** December 02, 2005, 05:15:18 PM »

The first thing you need is the schematic for your bike. I know you are not all that good at electrical, I excell at this area (as I have an Associates Degree in it) - this is why I am trying to help. A tool that maybe helpful that is available from many manufacturers is a test light that shows both ground and power in the same light. This lights up red when you have power and green when you have a ground. You have to hook it up to a known good power source first. I have one that goes everywhere with me that I got from Matco. I do not even start into electrical with out it. When you are staring at 30-40 wires it is always nice to know which one you have, power or ground and check it out with the schematic. A DVOM can work well in this area too but you are busy looking at the darn screen more than establishing power and ground like you should be.

While I do not believe in just changing parts until you get it right. I would have to say that there are two circuts in the ignition switch that are switched on at the same time in the switch. You could try a test switch. Dont mount it it just plug it in and try it.

More times than not a ground is the first failure in a circut. You will have to chase that down. A fused jumper wire can be helpful in this situation. If you do not want to change out a harness make sure your jumper is fused as it will burn wires faster than you can say damn. And you will be trapped into a harness exchange.

Start at the battery and make sure you have voltage. If yes then move onto connections to the battery. Then connections at the ground first (follow the black wire from the battery) and then move on to the power wire.

At the 15A main fuse do you have power on both sides of the fuse? If all other connections check out then start unplugging main group harness stuff (anything in a block group plug) and plugging it back in. Sometimes these connections get green and you have to mess with them to get them going again. I have had the connector at the ignition switch give me hell many times.

I hope this was of some help.

seaweb11 · « **Reply #10 on:** December 02, 2005, 06:25:26 PM »

This may sound stupid, but no one has mentioned it.
My bike did this a few times, Turned out it was simply LOOSE Battery conections. Tightened them up and away I went

But I must admit, that didn't turn the bike off, just made it imposible to start.

oldbiker · « **Reply #11 on:** December 03, 2005, 01:13:15 AM »

A quick check on the ignition switch can be done as follows. Take a 2 foot length of wire with a crocodile (alligator) clip on each end. Clip one end to the battery positive and the other end to any of the black wires in the harness. If your electrics now come on then your ignition switch ( or main fuse) is suspect.

egar · « **Reply #12 on:** December 03, 2005, 05:09:31 AM »

You folks are why this site is so fantastic. Thanks for all the ideas. I'll start plugging away today. I used to get frustrated with the bike, now I see problems as challenges. It has taught me patience.

bryanj · « **Reply #13 on:** December 03, 2005, 05:22:54 AM »

Hi, All the black wires shiould be 12v +ve with the ignition turned on( multimeter set to 20 v dc -ve to battery neg, +ve to any/all black wires) or just use a 12v test light. On the bottom of the ignition switch is a block connector into the plastic base check for 12v+ at the red wire which should be there all the time or the fuse/ wiring connection is bad. the plastic base was available seperately so that you could keep the same key but i think honda discontiued it a while back, at about the same time the switch (a 400\4 part) only became available as a lock set costing 100's of dollars/pounds like i said somewhere i have a couple but if i cant lay a hand on it within 10 mins it will be months, my lockup storage is that crammed

DammitDan · « **Reply #14 on:** December 05, 2005, 10:00:47 AM »

I had a bridge fuse (next to the rectifier) burn out on me cause I accidentally put in a 25 amp fuse instead of a 15. Dunno if it would make a difference here, but I'm just throwing out options. The bike sure as hell died on me that time!

DrMark · « **Reply #15 on:** December 05, 2005, 10:25:39 AM »

My 1978 CB550K did the same thing this summer....blown main fuse, it looked good, but still would not run. Changed the fuse and cleaned the terminals in the fuse box...runs like a champ now.

stevej · « **Reply #16 on:** December 05, 2005, 01:36:46 PM »

Whilst this electrical failure sounds like classic 15amp (main fuse)blowing.Even if it looks ok,I would suggest before looking too deep just check the connection between ign. switch base and the plastic multi wire connector that slots into it,these can seperate enough to kill power,Ive heard of people using plastic ties on handlebar ignitions to keep these together.

egar · « **Reply #17 on:** December 06, 2005, 05:20:56 PM »

You guys were right again. Bought a 39-cent fuse and it's running fine. Unbelievable.

brockj · « **Reply #18 on:** December 07, 2005, 06:25:05 AM »

I had the same thing happen to me on my 78 550K, fiddle with the fuse got it to run for a bit and the smae thing happened. I ended up pulling off the fuse box assembly and one of the wires running to the 15 amp fuse on the back came off. Apparently when I would fiddle with it I would push the wire back into connection. I ended up re-soldering the line on and no problem since.

Glad to hear it is running again!

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Author Topic: My '78 550k died while I was riding it. Walked it home. (Read 3559 times)

apormarkos

ElCheapo

brockj