1977 Honda Cb 400 F - Answered Questions & Fixed issues

inspec fuses-good lookin ones can be bad-also view wiring for cuts n corrosion-hows batery or other parts-no wheelies

if you have not used the bike for sometime this usually happens, this is a common problem with old bikes. just use it as often as you can and it will go back to its normal condition

yep thats a sticking float, Just lowe the bottom of it, and tap the float ever so slightly,, you can even tap the cover with the handle of a screwdriver sometimes and that will pop it loose without removing the cover

It sounds like a broken return spring. It should be inside the clutch cover on the right side of the engine. You will need to drain the engine oil and remove the screws from the cover to remove it. Work the shift lever up and down and try to see what had happened. Good luck with it

hi, yes there is a proper tool to stop the lower damper spinning inside, look down the fork tube you will see the damper, you could utilise a wooden shaft from a broom or similar, woul best find a long flat bar and grind the end away until it fits and locks the damper, alternatly you may try fixing the lower leg in a vice gripping the caliper lugs, do not grip on the tube area of the leg, then pulling on the fork stancion
(chrome tube) as you operate your air gun, try tightening as well as slackening them to break the seal,
good luck, paul

hi, this bike is uses a 12volt system,

cylinder head is getting red hot because it's running lean. Check to see if there is an aftermarket fuel filter in the fuel line somewhere, also the float hight in the carbs are set right. Also drain the fuel tank and apply fresh fuel. Check to see if the tank is rusted, also if it has a device at the bottom of the gas tank that turns on and shuts off the fuel (petcock) it's possible it has a fuel flilter in there as well.

*Note if you take the petcock off you will more than likely have to replace agasket for it. Given the age of the bike it will be hard to find a gasket.

Should be 120psi to 150psi in each cylinder.

Yes, it is a bolt. Click on the link below to view what the manual and automactic adjustments look like for your 1977 Honda CB 400F

http://www.dansmc.com/camchain_adjust.htm

After about 10,000 miles, the tensioner and guide need to be changed. If this is done the cam chain will be good for another 10,000 miles with adjustments every 2,000 miles

purchase a test light, it'll look like a pointed screw driver with a clear handle that houses a light inside it and has a wire attached and should have an alligator type clip on the end..now gain access to your battery and take off the negative wire, now attach the alligator clip to the negative battery wire that you just took off ,oh and make sure that the the key is in the off position ..now poke the sharpe end into the battery terminal post..if you have a short somewhere in your system the light will be on..now if it is on gain access to your fuse box and pull out one fuse at a time until the light goes out..when it goes out read the fuse cover to see what system is causing the short..eg the fan, headlight, brake light, turn signal, etc then you can then at least look at the wiring going to these system visuallly for chaffing, rubbing, our take out the bulbs themselves, sometime they can cause a short if there corroded real bad.

you must have 12.5 volts from your battery

Hi and welcome to the site,

Initially, check for +12 on the black wire from the ignition switch to the OFF/RUN switch and starter button.

Good luck and thank you for asking.

Look here ... http://hrca.honda.com/

loosen rear axle bolt and nut, tighten chain tensioner at rear axle,use the nut on the tension bolt to lock it down to the same calibrated distance(about 3/4 inch chain slack movement up and down not a total of 1 1/2) when the axle alignment is the same on left and right tighten the axle nut and bolt,lube the chain. Make sure you adjust the rear brake tension to make up for the wheel being moved toward the rear.

Honda uses both a Part Number system and a Honda Code to identify parts. The Part Number is in alpha-numeric form which includes a three digit 'middle number' that indicates which model the part fits (parts with a center number of "369" means that the part fits a Honda CB400F). Aside from the part number, each part is also identified by a 6-digit, numeric, Honda Code. Any Honda motorcycle dealer should have the appropriate parts breakdown on microfiche for your bike - which will enable you to identify the parts that you need.

Typically if the brakes have enough wear the range of motion to engage the shoes to the drum increases, this causes the cam to pass the high point. Remove the rear wheel and disassemble the brake hub. It should lift right out. Inspect and replace the shoes if needed, clean and lube the internal cam and reassemble. You can find the technical info for proper adjustment in a Clymer Motorcycle Repair Manual (Smart Purchase)

autozone

Just check the wiring in the switch housing on your control sets. The contacts inside sometimes oxidize in the old hondas, stopping a good connection. A quick rub with a wire brush will sort it out if that's the case. Lovely looking bike BTW.

Hi, E-mail Honda themselves with this question & details they will be able to tell you very quickly. Please leave me feedback, best wishes, Malcolm Campbell.

The old honda twins did suffer with ignition problems,( ofcourse they all run well at one time) CDI units and Alternators although checked out were often the cause of failure to spark, assuming you have checked all the obviouse, engine cutout in centre position for running, next remove 1 spark plug cap leaving the other connected to the inserted plug, holding the bare leade aprox 2mm away from the cylinder head, crank the engine over and check for a spark, if ness touch the lead on the head, if a very weak spark is visible then the ignition side of the alternator has failed, often the ignition coil can fail when first used after a long time standing