Starter solenoid won’t engage?

Gooday All,
My starter solenoid was playing up. Replaced 4 pin plug as old one was a bit crappy. Didn’t work. Swapped solenoid for a known good one. Didn’t work. Bought a new one, solenoid only buzzes and doesn’t engage?

So you have eliminated the solenoid as the fault.
I would be checking the starter switch on the handlebar to make sure it’s making full contact.
A wire from the live on the battery to the yellow and red wire on the 4 pin plug will operate the solenoid if the start switch is at fault.
If it still does not operate,pull the clutch in and try again,the clutch stitch provides a direct path to earth for the green and red wire on the 4pin plug.
If that works it would suggest the silicon rectifier is faulty.
you can also go from the earth terminal on the battery to the green and red wire on the 4pin plug to eliminate a wire fault (the bike will however start in gear)

Gooday Bif,
Thanks for the suggestions. I did what I now realise is a stupid thing. Because the FE and FF I have here have different wiring colours, I wasn’t convinced that I hadn’t simply reversed the 4 pin plug, Long story shot, ha, but I reversed the plug and got nothing but some mysterious white smoke in wiring above battery before removing plug. I’ll now have to intake the loom in that area to check what damage I have caused. What a fecking Wally!
Will let you know when I have a chance to check

Non starting mystery continues, just tried substituting another complete starter button assembly, and nothing.
One strange clue - with the original starter switch, when I push the button there is just a slight noise from the solenoid as if it is moving, but not throwing in, but the tacho needle flicks up to 5000-6000 rpm, so some sort of feedback somewhere?
my next steps will be, take fuel tank off, and work my way methodically through fault finding, ensuring that clutch diode etc are all working.
Have 3 bikes here, 1 FE, and 2 FFs but each of them has a variation of the colours at the solenoid 4 ping plug, so will have to take my time to check.

I’ll check the diagrams and see if I can help out

From all the manuals I have the colour coding is the same for all models at the 4 pin plug
The red and the red/white wires are feeds from the main fuse
The green/red is the earth for the solenoid coil
The yellow/red is the live feed for the solenoid coil
What colours do you have?

Hi Bif,
a very Happy New Year to yourself, family, and forum members! I believe it’s a really big deal in Scotland, or at least that’s what a Scottish mate told me?
I have removed the handlebar starter switch, checked with multimeter, and also tried substituting another switch, no luck. I believe the feedback to the tacho is indicating that I have the connectors in the wrong positions in the 4 pin plug for solenoid.
The clutch diode was burnt out, as a result of me trying the connector the other way around, now replaced. All fuses checked and OK.
My 85 FF has red, black, blue, and green at the 4 pin plug.
Another 85 FF- 200 serial numbers off has Red and white, red, green -red, and yellow red. Looking at this plug from the solenoid mating end, with the cutaway corners uppermost, the colour-positions are Red/white in top LH corner, Red in top RH corner, Yellow and red bottom LH, and Green/red bottom RH spot.
I haven’t altered anything on this second plug-bike, but its a motor and frame, so cant check operation, however I believe this wiring, and plug positions are correct. I think that I have somehow got the wire positions wrong when I fed the new female connectors into the plug socket. I`ll try your suggestions re hotwiring above, and also make sure clutch micro is not the problem.
Thanks for your help, as usual! onwards on the VF journey…

I checked everything I have, yesterday(manuals & wiring diagrams) but then got caught up with New Year celebrations. But as usual Bif is absolutely correct. If you have different colours then someone has messed around with it and you don’t know what has happened. Different colours on the solenoid side of plug, could mean non standard solenoid. Different colours on the other side of the plug means someone has messed with the wiring. If you run a jumper wire to the yellow/red wire at the solenoid straight from the positive side (red) battery, then the solenoid should work. If not, run a jumper wire from the green/red wire at the solenoid straight to the negative side (black) on the battery. if it still does not work then you probably have a crook solenoid. The way you describe the solenoid behaviour suggests that there is a great deal of resistance in the circuit. It could also mean that you have a faulty Neutral switch and/or clutch switch, you can eliminate them by putting jumper wires across the two switches to take them out of the circuit, but be aware that your bike may start in gear. I had a similar problem on another one of my bikes, but it was intermittent, and after many hours of testing and searching I found a spider between the contacts of the starter switch(button). had to strip the switch and clean it out, cleaned the contacts and WD40, haven’t had any trouble since. Do you have wiring diagrams for your bikes? If not let me know and I can E-mail a PDF to you at A3 size. (Much easier to read). There is a rectifier (one way) in the circuit also which could explain both problems because if it is completely open circuit then no power will get through. If it is damaged and causing a high resistance then it could be causing the noises you hear from the solenoid. Are you sure that you have found and fixed all the damage caused by reversing the plug because in your case where there was smoke there was Fire damage to insulation.(only way to get smoke) Of course I am assuming that you have checked all electrical connections to make sure they are secure.

Hmmmm, have just burnt out the second clutch diode when swapping wires at solenoid, must have reversed polarity!
My problem is that I can’t use the hints about hotwiring because I can’t be sure of any of the 4 pin plug positions.
Have worked out that the positive in is one of the blades closest to the solenoid coil from ignition, and runs back to v regulator. Just have to work out the correct position of the other 2 control wires? Will make jumper leads for clutch diode connector, and clutch lever micro switch to eliminate those from troubleshooting process.

Don’t move any more connections. Have a look at your second bike’s wiring and copy that in the plug.
I will try to get a photo of the setup from one of my bikes or maybe bif already has one. I will try to find you the easiest way to identify each wire that is not the same colour. Could take a little time. Maybe you will need to PM me your mobile once I have worked it out then I can call you to work through it with you

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what colour wires are on the solenoid part of the plug

Ok so looking down onto the solenoid looks like this

Gooday Bif and Jovimill,
thanks for the help and suggestions so far!
Image with connector is what i just located on a spare wiring harness, things you find when you have a good look! Bif, the wiring on the FE, spare loom, and wiring on another FF appears to be the same as your pic, thanks.
Image without connector is the wiring I have on my problem bike. My manuals, both genuine Honda, and Clymer, show the same colours. I’ve really complicated things by my botched plug and connector replacement.
As it’s now obvious that my wiring is non standard, I’ll unwrap, and trace back to check connections and any splices I find and check continuity. I`m tempted to cut and join correct wiring from the spare harness, but loathe to do that at this stage- will try to find the splices and then replicate the original colours and plug. No luck in finding a good 4 pin Honda type fitting with the alignment notches to match the solenoid. The hunt goes on, thanks for the international support men!

I unwrapped the loom behind the rear cyl head area, where the solenoid wiring runs back into the loom. I found that someone had done a good job of joining new wires to the solenoid 4 pin plug- unfortunately they had not replicated the standard Honda wiring colours, FFS!
see pic
Onwards and upwards!

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Looking good, hopefully you can sort it out from here. Electrics can be a challenge. Good luck and let us know how you finish up.