[kine8282`]

Howdy...hope someone can help me out.

I don't have spark on my CB550F. I bit of history on the bike; I just got it last weekend from this guy who said that he was changing the handle bars and once he finished he couldn't get it started. A buddy on mine just came over this morning to look at it...checked the usual suspects; points (good), battery (new), plugs (good condition). Electronics was his kryptonite so he couldn't figure out why I wasn't getting any spark.

I lights and horn work so I don't think its the battery. I just checked the birds nest of wires behind the headlight and everything seems to be in order, I did find a brown female connector without a partner but according to my Clymer brown is for the taillight and that works just fine.

I was trying to find a thread for this on the forum but nothing was working...can anyone offer help? Thanks.

 

[kenessex]

Since you ar not getting any spark on any cylinders then the problem has to be either power to the coils or kill switch. Check the wires from the ign. switch and the wires from the right handlebar switch. Off hand I don't recall tthe color codes for sure but I think the switched hot from the ign switch to the coils is solid black and the kill switch is black with a white tracer(possibly yellow). If the insulation for the kill switch wire got cut or pinched during the installation of the handlebars it will be shorting out and killing the spark. If you unlug the kill switch wires and the bike has spark then your culprit is somewhere in that circuit. If that doesn't fix it then check to see if you are getting 12V to the coils at the black wire, not the yellow or blue(they come from the points).

Good Luck,
Ken

AHRMA 412
Vintage racing - old guys on old bikes

 

[kine8282`]

Thanks for the reply, I took open the kill switch and found that the wires attached to it look good...i mean that it looks like the wires are still soddered on to the little circuit board, how do i know that its not working right? Is there tell-tale signs that its broken?

 

[joe c]

which year is it?? the 77 and 78 models have a piece of crap for an ignition switch. it can be really finicky. which year is it?? you can jump the poles if its a 77 or 8 and that would tell you if its the switch. while he was yanking it around, he obviously loosened something. check your fuses too. under left side cover in a little box maybe.

jc

 

[joe c]

i personally think youre searching the wrong places pulling things apart. check the easy stuff first. the keyed switch if its a 77 or 78 is really easy to remove and its retarded how its put together. i wouldnt be pulling apart the tricky stuff because you could compound the problem. search the easy stuff first.

and get a voltmeter. or at least a continuity tester.

jc

 

[joe c]

duh, its a 75.

JC

 

[Geeto67]

75 meaqns that the wires run inside the handlebars. I had a problem like that on my cb750 last year where the kill switch wires had frayed inside the handlebars and were shorting out. Unfortunatly the only way to check this is to pull the bar switch and visually inspect the entire length of wire so I suggest it as a last resort. Check the coils for cracks and check the coil grounds before you go ripping your handlebars apart.

 

[kenessex]

Ok, I just looked at a wiring diagram and the hot lead to the coils is a b;ack ith white tracer. It comes straight from th ill switch. At the coils see if the blackw/white has power if the ign switch is on. If it does then the you should have spark. If it doesn't then pull out the headlight and sart checking the wires in there. This is a simple process if you follow the steps. You don't need to tear switches and stuff apart yet.
1. Unplug the connetor for the ign. switch. White rectangular plug. Is the Red wire on the main wiring harness hot(12v)? No? Check your main fuse or battery connection.
2. Check the ign switch for continuity between the red and black. With the switch off no continuitty, switch on there should be continuity.
3. check the connectors from the right handlebar switch. (individual connectors) Check the black to the switch, is it hot with the ign. on? Check the Black w/ white tracer, with the black wire connected is the black w/ white hot with the ign switch on? If not, connect the black straight to the black with white tracer bypassing the kill switch. Spark now?

Somewhere in these steps you should find the problem. It isn't rocket science, just take your time and be logical.

Ken

AHRMA 412
Vintage racing - old guys on old bikes

 

[Geeto67]

also check the plug wires, make sure the boots are tight and the electodes are making connection. plug wires are probably the most often overlooked item on an old honda.

 

[kenessex]

Just in general, when dealing with an electrical problem always look for common factors. In the case of Honda ignition systems on 4 cylinders, they run paired ignition systems. That means that if the spark is missing in cyl. 1&4 or 2&3 together then the problem is in the coil or points or the feed or ground to that coil. If the spark is missing in only 1 cylinder then the problem is the wire, cap or plug. If the spark is missing in all 4 cylinders then the problem must be in the power to both coils which comes through the ign switch through the kill switch to the coils. Again, with the twins with 2 coils, try and isolate it to one side or the other or if spark is missing from both cylinders look for the common factor. If possible, get a wiring diagram and start tracing wires. The other nice thing about Honda is that their color codes are consistant throughout their models, so any Honda wiring diagram will give you a good idea of what to look at.

Ken

AHRMA 412
Vintage racing - old guys on old bikes

 

[joe c]

cool, yeah, what he said!

since were on electrics, my buddys got a 75cb550. first year for the headlight on all the time. he uses the elec start alot. he rides to and from work, maybe about 20min ride. sometimes on the highway, sometimes not. hes got a new battery and it seems to be charging fine. but the battery will die after about 3 days or so of average riding. is it because of him using the electric start all of the time?? i mean, did the 75 model year really suck like that?? it seems like with that being such a problem with the brit stuff, the hondas, 10 years later wouldnt have that problem. hes tested the output of everything and got 13v on stuff. is this something other people have experianced??? are those bikes that dumb?


jc

 

[736cafe]

joe,
i keep telling him thats his battery problem is due to his electric start button pushing habit. he doesn't seem to like that answer though.

scott from chicago
ahrma #527

 

[joe c]

yeah, i dont buy it either totally. just seems wrong. like the bike would have a big reputation for that. and not that i know everything about it, but ive never heard that before about that bike. i mean, why doesnt mine do that??? if it charges at the same rate, the battery is the same, and the lights go on, and the starter requires the same amount of current, whats going to make his die and mine not? wheres the difference?? just seems way too short sighted for honda.


and i use my electric starter about 99% of the time now. cuz im lazy.

and i want him to put a volt meter on it while its cranking to see the drop. how much voltage will that thing suck out of it while its cranking. id like to check mine too. just out of curiosity.

jc



Edited by - joe c on Oct 02 2006 7:07:13 PM

Edited by - joe c on Oct 02 2006 7:10:33 PM

 

[kenessex]

Joe,
The problem is that the breakeven point on those models was about 2200 RPM with the keadlight on. The cure is to keep the RPMs up and put a switch in the headlight circuit so you can shut it off while the bike is sitting warming up. Ride it like it is somebody elses and you won't have a charging issue.

Ken

AHRMA 412
Vintage racing - old guys on old bikes

 

[joe c]

yeah, he knows that. he knows it puts out power at about 2200 from the diagnostics hes done. just seems like a buzz down the highway for 15 mins should be enough to get it back up again. it seems stupid that youd have to put in a switch to shut the light off. like i said, short sighted for honda, so it makes me doubt. i mean, is this a problem thats been there since they rolled off the floor??? and people actually bought this? i just cant believe that. especailly in 1975. and people complain about british electrics. my lucas stuff is the bomb.hell, the bonnevlle always started easier than the honda did in the spring. plus, if you fast idle it thats about where it sits anyway. about 2300. well, choke it. plus, i dont have those problems with mine, even if im just buzzing around the neighborhood. it just doesnt explain it.

i only ride my own bike like its someone elses!

jc

 

[kenessex]

Joe,
Yup it is stupid to have to put a headlight on off switch on it, but that is the way it is. Honda did the simple thing in 75 when the law said that headlights had to be on all the time. They just took off the switch and left everything else the same. On some bikes the system was good enough and matched the riding style of the owner and Honda got away with it. On other bikes of the same model it wasn't good enough and the batteries went dead. My sister and I both had 1975 CB400Fs. Hers needed a headlight switch and mine didn't. When I used hers I didn't need the switch, cause I rode it like it was hers. I did crash it twice and tore out the oil drain plug on some railroad tracks. It sucked taking good parts off mine to replace her stuff so she didn't know I beat it.
If you want to throw parts at it that may or may not do any good, sometimes the regulator rectifier on those could be replaced and make a difference. Other than that rev it out and throw it on the trickle charger every couple of days.
P.S. It has a kickstarter.

Ken


AHRMA 412
Vintage racing - old guys on old bikes

 

[joe c]

thats the most rediculous thing i have ever heard. makes me want to only ride my triumph. ill pass it along. lame.

jc

 

[kine8282`]

I'VE GOT SPARK! Thanks everyone for helping me find the problem and teaching me how to fix it. With the help of my $2 test light and following the the advice from all you folks, I had isolated the problem which was on the kill switch which wasn't completing the circiut. I hot wired it through the headlight by connecting the black/white wire with the black wire and vroom vroom I can turn the engine over.

Thanks again ya'll...now that I've got the engine going I can see that there are other things I need to work on but let me cruise the site so that I don't ask the same question somebody else did, but I'm stoked to fix this hurdle...one victory at a time...

 

[joe c]

awesome! way to go.

woohoo, our work here is done, now we can get back to serious things, like picking on aaron.

jc