Ignition problem

[Maax1200]

If your model has only one fuse and two grease nipples for the swingarm (one on each side), I'd say yours is a K1, as sold in Europe. At the end of the Owner's Manual there are 4 different wire diagrams. For you that is probably the -ED type. Unless your bike has been imported from elsewhere.  http://www.honda4fun.com/pdf_libretti/500/CB500_k1/CB500_K1_4.pdf

The bike only has 1 fuse. There was no original swing on it since the former owner rebuild it as a mucle machine, square swing arm, fibre glass body and all that. Iv hade to find, more it less, half a cb500 on the internet (never again). I live in Sweden and the bike was registred in traffic in 1974. No private import or anything.

[Maax1200]

Thank you for all replys. I will follow all advise and report back on progress.

Might take a few days since we have the hottest days of the year here in Sweden (+30C) and i will use that as an excuse to do absolutly nothing, and loving every minute of it.🙂😎

[Maax1200]

Update.

So, got myselfe a multimeter and it seems both ignition coils are faulty. All caps but one is also shot (extremly high resistans in two) I get good reading from the secondary surcit but primary is completly dead on both coils.

Any advice on if i should get new stock coils from David Silva or new Magna coils? (Dynatek is just to expensive). The bike has Dynatek electronic egnition fitted.

[Bryanj]

Very unusual for both coils to go< if fact unusual for any coil to go on primary, resistance is very low so worth reckecking with different meter

[philward]

Have you seen Ash's coil fix Magnus? As previously said by Bryan, general consensus is it very unusual for stock coils to fail -
http://info.sohc.co.uk/download/ashs-ignition-coil-fix-2/
This post will also give advice on checking coil values (from memory)

[Maax1200]

I will check again with another meter and thank you for the link.


With that said, the problems keep flooding in. I removed the assembly behind the left side cover to check faulty wires and a general cleanup. Checked for continuity and all seemed ok, no broken wires etc. Reassembled everything aaaaaaaaand.....the bike is completly dead, no lights no nothing, just utterly dead. Iv changed nothing between removing the assembly (starter selenoid etc) and reinstaling it again, very carefully i might add. Its like the fuse popped except it hasnt.

Im on the verge of giving up. I will check everything again and after, if i dont find the problem, its of to the lowest bidder im affraid (Have several other projects that need attention to and there are only so many days in a year).

I mean, everything except the coils and the sub assembly behind the left sidecover is brand new so how many culprits can there really be?

[fogrider]

If you mean that little cover on the left next to the coils, that's where the main earth wire goes to the frame  on mine. Is that OK ?, have you disturbed a poor  earth connection ?
Worth a look maybe....

[Maax1200]

I mixed it up before, its secondary surcit om the coils that are faulty. Managed to get hold of 2 secondhand ones and they confirm its not my multimeter thats showing wrong. So i now, at least, i have 2 working coils (for now) but im starting to wonder if there is a problem with the voltage regulator maby, giving to mutch voltage burning stuff?

I will keep digging and rechecking earth wires etc but the whole system going dark makes me think something happend to the egnition switch, maby due to mutch voltage?

Only times i ever seen system going dark before is because of main fuse blowing (not the case here). The next thing i can think of is the egnition switch.

P.S. Thank you all for your input and hoppfully i will solve it in the end.

[Maax1200]

If you mean that little cover on the left next to the coils, that's where the main earth wire goes to the frame  on mine. Is that OK ?, have you disturbed a poor  earth connection ?
Worth a look maybe....

Sry, i meant the subassembly behind the sidecover below the seat.

[Maax1200]

Check all the connections again, it's quite common for one of the connectors to get pushed out as your connecting the 2 block connectors, also check for corrosion. It's clear you've just disturbed a connection that is vital, in particular check the connector to the fuse.

Will check again. I made fresh new connections to the fuse but will try again. It just has to be that or the egnition switch.

[Maax1200]

I think i have solved the problem (i think).

The original issue was that the turn signals and oil lamp didnt work. Turns out those two cables was switched on the new main harness, grey to blue/red. So now that issue is solved. So thats a tip for those who buy new "quallity" replacement parts. Allways check so that wires isnt in the wrong place.

My second issue ended in the bike going dark. After checking all the connections and confirming that everything was fine i finally came up with the idea to bypass the starter relay and viola, it all works. Now i need to order a second hand starter relay and everything should be ok. The relay turns the starter motor if i bridge the two terminals but it doesnt seem to let through any power from the battery to the main harness.

I need to check the voltage regulator so that isnt the cause giving to mutch voltage. Maby that killed the switch and even the coils (should have blown a few bulbs first i would think)?

[Bro550F]

Good work Sherlock, keep us updated. 

[McCabe-Thiele (Ted)]

I belive odd job is right with his theory

[Bryanj]

It doesnt matter which way round the big cables go but it does matter which one the small red goes to which is the one from battery

[Maax1200]

I belive odd job is right with his theory

Yes, the yellow/red and black wire is "pointing" towards the airbox if that makes sense.

Hopefully a replacement relay will solve everything.

I did have to replace the coils since they where faulty to.

Is it  just random that both coils and starter relay malfunctioned at the same time? Voltage regulator?