550 horn problem

[mickwinf]

Hi guys, well the 550 k3 rebuild is almost there, i booked an mot for thursday, only the horn is not working.Neither did 2 spares,so off i went and purchased a new one, result, still no horn.I checked the horn was getting power from the black wire, it is,and if you earth the other terminal it beeps,so must be switch, but this is brand new.All connections are good so i stripped the switch and i can not work out how the horn terminal goes to earth when you press the button as it is encased in a plastic block ( it is the type that has a PA headlamp flash combined with the horn button) Any ideas anyone??

[stidds]

I don't know what your new horn is like, but I was having the same problem with my new horn (not a Honda item).

Then I realised that there is an adjustment screw on my horn, I ran a wire to each of the horn terminals and then attached these to a new battery.  I found that the horn still didn't work, so I played with the adjustment screw and when it made a nice loud sound I put it back on my bike and it worked.

[Mercury]

 Not a lot of help but I have a similar problem, stripped the hand grip and it had no wiring at all to the horn switch! Have decided to completely replace that switch with a round micro-switch. By the way, bit confused as to why all the black wires supply + volts!

[mickwinf]

i have solved problem.In the handlebar switch horn button there are three wires, one black + feed, one blue to headlamp main beam for flash, one light green to horn, nothing goes to earth as my haynes manual suggests.What happens is, when you push to the right to PA the black and blue wires connect, so operating the h/l flash,when you press straight in for horn the black and l/green wires connect, sending a + current to the horn.ok so far, but the problem is that the other wire to the horn is also a black + feed wire from the loom,so in effect you are getting 2 + feeds and no earth! My solution was to disconnect the black wire from the horn and replace it with a wire to earth on the mounting bolt,now it works correctly.My only question is how the heck did it ever work when new??, Cheers Mick

[florence]

I've got a 550 left hand switch and the horn didn't work.  I simply wired it to the headlamp flashing switch instead.

Incidently, headlamp flashing should rarely, if ever, be used, it is not recognised as a signal in the Highway Code or by the Institute of Advanced Motoring and can cause confusion and accidents.  The horn is the correct device to give a warning and in all other situations, decisions about whether to proceed should be left for other drivers to make for themselves.  Someone very close to me was killed because a driver, trying to be helpful, waved another car across a junction into the path of a motorcycle which he had not seen and had no chance of stopping.

[mickwinf]

good point Florence, flashing headlamps should only be used to inform someone of your presence NOT to say "you go first" The problem is most people dont know this, so can be confusing as you said, so be careful out there!!

[stidds]

It is a good point.

I am a Driving Instructor and these days we always tell our students to never use flashing lights to beckon someone through or let someone out of a road, in fact we tell them never to beckon out in any form be it flashing lights or hand signals as it can confuse other road users.

Most people think when you flash your lights etc that you are saying 'it is SAFE to go' when in fact you are saying 'I will sit here and let you out but you must make sure it is safe to do so'.

If someone used their lights to flash another road user or beckon them on/out on a driving test they would probably fail that test.  Driving Examiners take a very dim view of this.

[mickwinf]

hi Stidds, i too am a driving instructor up in Scunthorpe, playing with the bikes is a good way of de-stressing after a long day!!

[Bryanj]

The switch is off a newer model, the LH switch changed at the same time as the start button system changed

[mickwinf]

thanks to all who have given advice and encouragement over the last few months, bike passed its first MOT since 1982 this morning!! Just tax to get then on the road, it ran ok on the trip to the MOT, a bit noisy, valves and camchain will need adjustment also carbs, but was the gear train always so noisy? This bike only has 6,000 odd miles from new, i dont remember if they used to make this noise back in the 70s. Feels great though!!

[florence]

I think they are all fairly noisy, especially the clutch and primary chain.  If the tickover is too slow they get pretty lumpy and clattery.  Why on earth Mr Honda didn't put in a primary chain tensioner I do not understand.  Oh well, seems to work even if a bit noisily.

[Yoshi823]

All of my 550s have been quiet, from the '75 F1 with 37,000 on the clock when it was stolen, to the '78 F2 with 49,000 showing when it was sold. If the tensioning of the cam chain is correct, the ignition timing is done properly, & the inlet manifold 'O' rings are sealing properly so that the air/fuel screws make a differance when adjusted, there should be no reason why the engine should be noisey. Careful balancing of the carbs should only be attempted once everything else is done.

[mickwinf]

yes i will need to reset all the valve/ignition settings now it has been running,will hopefully quiet it down!