Questionlast year around september my bike was working electricaly fine but this year the horn doesn't work on the bike but does work when attached directly to the bat .same with the headlight it works directly with the bat but not on the bike mounted in the headlight frame i check the wires for current and lightly sanded the horn contact button still nothing i am inclined mechanicaly but this is beyond me also when i turn the petcock on the one carb leaks gas out the overflow but when started it stops and is fine after that /thank you the bike had been sitting out side under a tarp for 10 plus years when i got it but i did clean out the one fuel bowl where the float needle was stuck i don't think it's the same carb that i cleaned out but not sure
AnswerRon, you are lucky to have got it running at all after sitting for 10 years. The whole fuel system should be attended to ... fuel tank, petcock, fuel lines and carb o-hauls for all four carbs. Varnish and debris are probably floating around in the carbs waiting to cause more problems. A possible fix is to mix up some Yamaha Carb cleaner solution and run it down inside the carb bank. Let it sit overnight and then drain. Follow the directions on the bottle.
Most Honda horns run power through the horn coil inside, then ground the circuit through the horn button in the handlebar switch. If you have the switch apart and run a grounded jumper wire to the horn button contact, the horn should sound. If not, you have to check all the connectors back from the horn button to the horn assy. With the switch ON, you should have power in and out of the horn assembly. Disconnect one of the leads, check with a 12v test light. Find the hot one, leave the other horn wire connector disconnected and attach a grounded jumper wire to the horn lead. If that works, then the problem is the ground path back to the horn switch. If you have no power into the horn with the switch on then you have a bad fuse or other wiring connector. On a bike this old, I would inspect every wiring connector and ground connection on the bike.
The headlight issue may be the starter button switch contacts. This is a known issue with this era of bikes, as the use of automatic ON headlights requires that the switch make two separate circuits....
Button OUT is headlights ON.
Button pushed IN, headlights go out and the starter circuit is activated.
Also if the high beam is selected the front running lights go OUT until the switch is returned to LOW BEAM position again.
Expect fork seals to start leaking and the front brake caliper to stick, along with possible master cylinder failures due to contamination of the fluid. Check the whole bike over carefully, using a service manual and ride it gently while it gets used to being in service again.
Bill Silver
