Topic: Honda 400/4 1975-77 super sport please help

[Joshy24]

Hi guys I have found my dads old Honda which has been sat in the shed for some years, the bike is in good shape (apart from some rust) and complete apart from the kick start. To cut the story short the battery was completely dead an worn out I have bought a new battery but still when I out the key in the ignition there is no sign off life at all no lights, horn ect. . . I have checked the fuses and they seem fine I have very limited mechanical knowledge. Any suggestions Thank you josh

[Stev-o]

I have checked the fuses and they seem fine...

Seem fine?  That does not rule out a bad fuse as they cannot be checked visually.

Do you have a voltmeter?  If no, buy one, you will need it...

[Bodi]

You really need a multimeter to do any electrical troubleshooting.
The fuses can "look good" and be bad but if it ran before being put away they are probably OK.
The ignition switch is the likely problem. The contacts can get corroded over the years and lose connection. The keyswitch plug may be in such a state as well. The plastic parts that hold it together get brittle and break, possibly the switch part has just fallen off the lock part.
Confirm your new battery has somewhere around 12V output.
Check voltage from ground (either battery "-"or an engine mounting bolt) to both sides of the "MAIN" fuse. Then check voltage on any black wire female connector with key ON.
Download a 400F wiring diagram, get the original Honda one from the service manual or owners booklet (http://manuals.sohc4.net/cb400/technical_reference/WD40075.jpg). The Clymers etc diagrams are not accurate.
It will be an excellent idea and a learning experience to remove the tank, headlight,  and sidecovers then clean all the bullet connections: corrosion will have affected them and this causes MANY electrical issues. Remove the left side engine cover, there are five bullet connections under there that can really screw with the charging system if not in pristine condition.

Anyway: best of luck, the 400F is a beautiful riding machine. Not for coast-to-coast cruising, true, but for getting around town or burning up twisty country roads it is hard to beat - light, quick handling, and fast enough to be exciting but not powerful enough to be dangerously deadly. Mistakes tend to teach a lesson, they don't just plain kill you.

[strynboen]

only turn the key one step..if you turn it 2 steps it are only pos light posision(euro bikes)...thek for korodet vires..and yes a multimeter and thek for voltage from the battery and ahead in the viring loom..

[Deltarider]

The CB400F was a typical allrounder launched in the days a 500cc bike was still considered a heavy machine and a 750 a superbike. It's perfect capable of doing long distances. I wouldn't ride it along town where a Honda Cub is all what it takes. My girlfriend in 1980 on her CB350F rode all the way through Europe and over the Peloponnessos to the very South of Greece and when we returned from our 6 weeks holiday we had done over 10.000 kms. Òn autostrada and autobahns we maintained a cruising speed of around 130 km/h. A friend of mine on his CB400F rode al the way to Morocco, toured the country and returned safely. His 400 is still in his garage next to his 600cc Honda Deauville. Americans just have a different perception used as they are to oversized engines. I'm 6'5, weigh 90 kg and simply don't want a bike that weighs over 200 kg. Parts position for your bike is very good thanks to David Silver.
About your electrics. If you want to learn more about your bike, a DMM is handy. If you don't have one, consider an automotive type that can read also tach as well as dwell and can handle 15A. When I bought mine they were a fortune, nowadays they're quite cheap. I wouldn't start with disconnecting all connectors. You'll learn nothing out of that. Pinpoint the problem. The fuses must be inspected however. The ends must be clean and shiny as well as the clips that hold them. Sometimes it's enough to move them a bit.
With your manual, wiring scheme and a DMM you must be able to do some basic checks like: is there a good ground, does the + reach the starter solenoid, the fuse box and the ignition key switch. Then this: at the beginning of each riding season, first thing I do is: switch the key (and the kill switch) some 15 times. This usually is enough to 'clean' them.

[John Eberly]

Welcome Josh -

I have a 400/4, great bike and fun to ride. Not too many out there like it.

Bringing a rusty one back is a long road to go if you don't have a mechanical background, but it's a great way to learn.

In my experience, you'll get a lot farther if you find somebody local to help you through the process. I didn't see where you are located - maybe post that and see if you can make a local friend to mentor you. It's really frustrating for everybody to try to troubleshoot over the internet. It can be done, but you will be offered a lot of advice with no ability to judge if it applies to your situation - all in good faith, but there's nothing like "being there" when you are troubleshooting.

The suggestion to get a meter is a good one. You can use it on the "DC Volts" scale to check if the battery is charged and whether your switches are working. You should be able to trace through the wiring to see if there are any faults. There are wiring diagrams on this board to guide you.

Best of luck!

[Deltarider]

In my experience, you'll get a lot farther if you find somebody local to help you through the process. I didn't see where you are located - maybe post that and see if you can make a local friend to mentor you. It's really frustrating for everybody to try to troubleshoot over the internet. It can be done, but you will be offered a lot of advice with no ability to judge if it applies to your situation - all in good faith, but there's nothing like "being there" when you are troubleshooting.

Excellent advice.
 

[magnum56]

In my experience, you'll get a lot farther if you find somebody local to help you through the process. I didn't see where you are located - maybe post that and see if you can make a local friend to mentor you. It's really frustrating for everybody to try to troubleshoot over the internet. It can be done, but you will be offered a lot of advice with no ability to judge if it applies to your situation - all in good faith, but there's nothing like "being there" when you are troubleshooting.

Excellent advice.
 

Looks like he is on the other side of the pond ... his profile indicates "Liverpool".

Wonder if he's anywhere near Abby Road ? 

[Stev-o]

In my experience, you'll get a lot farther if you find somebody local to help you through the process. I didn't see where you are located - maybe post that and see if you can make a local friend to mentor you. It's really frustrating for everybody to try to troubleshoot over the internet. It can be done, but you will be offered a lot of advice with no ability to judge if it applies to your situation - all in good faith, but there's nothing like "being there" when you are troubleshooting.

Excellent advice.
 

Looks like he is on the other side of the pond ... his profile indicates "Liverpool".

Wonder if he's anywhere near Abby Road ? 

Or Strawberry Field?!

[Keith]

No, Penny Lane!