1970 CB450 K3 - Bringing it Back project

I found some time to take a look this weekend.

First, I happened to notice the bulbs within the left speedometer dial were dangling down, and when I pushed them up, the headlight and rear came on!
Further attempts to figure it out failed since it they dropped off shortly after when I tinkered more, but the fact it lit up tells me it must be some sort of grounding issue.

Can anyone define how those are supposed to be connected in and grounded? Both the left most and middle in this picture were hanging down, and both have electrical tape to make them fit in the holes better.
Do I have too much tape on them perhaps? The rubber plugs arent working any more to hold them in

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I also noticed some (oil?) residue on the left side of the engine I hadnt seen before. Not sure what this indicates
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The plugs look good to my eyes. As one might hope, and neither rich nor lean, but I'm much of a noob and you can tell me otherwise
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The plug is a little dark, but I don't think it's a proven the way it is.

The fins on the head appear dry, so that oil may be coming out from the head gasket. The wind blowing over the motor trends to push pull from the front to the sides, so it doesn't necessarily leak where you see the oil after a ride. The tach drive seal and sometimes the header gaskets can also leak depending on what's going on.

Did you rebuild the top end? Can't remember offhand, but if yes did you ever re-torque the head?
 
MrMoonbeam72 said:
Can anyone define how those are supposed to be connected in and grounded? Both the left most and middle in this picture were hanging down, and both have electrical tape to make them fit in the holes better.
Do I have too much tape on them perhaps? The rubber plugs arent working any more to hold them in
Click to expand...
For the instrument lights power for the bulbs enters and exits through the 2 wires and the bulb holders are insulated from vibration by the rubber mounts so not grounded there. Due to the age of the holders there may be corrosion on the center pin and around the metal shell of the holder. The spring that holds pressure on the center contact may be collapsed and not applying enough pressure. I would pull them one by one and inspect the holder for any issues. Also the problem could be on the connector end of the wires inside the headlight bucket. The bullet connectors could be loose or corroded and when you push the holder it moves the wire enough to make contact there. The wiring diagram in the FSM is usable but if you can find a color diagram somewhere it makes it a lot easier to read. I have a color copy for the K5 which should be very close to your K3 and I would be happy to send to you if you like. Just PM me.
 
RobMan said:
For the instrument lights power for the bulbs enters and exits through the 2 wires and the bulb holders are insulated from vibration by the rubber mounts so not grounded there. Due to the age of the holders there may be corrosion on the center pin and around the metal shell of the holder. The spring that holds pressure on the center contact may be collapsed and not applying enough pressure. I would pull them one by one and inspect the holder for any issues. Also the problem could be on the connector end of the wires inside the headlight bucket. The bullet connectors could be loose or corroded and when you push the holder it moves the wire enough to make contact there. The wiring diagram in the FSM is usable but if you can find a color diagram somewhere it makes it a lot easier to read. I have a color copy for the K5 which should be very close to your K3 and I would be happy to send to you if you like. Just PM me.
Click to expand...
Sounds like you're telling me even if these were dangling everywhere, the issue is either on the bulb and socket end, or the other end to wherever they lead to. Nothing to do with how they are pushed in or mounted - i'll dive in :)
 
stl360+450 said:
The plug is a little dark, but I don't think it's a proven the way it is.

The fins on the head appear dry, so that oil may be coming out from the head gasket. The wind blowing over the motor trends to push pull from the front to the sides, so it doesn't necessarily leak where you see the oil after a ride. The tach drive seal and sometimes the header gaskets can also leak depending on what's going on.

Did you rebuild the top end? Can't remember offhand, but if yes did you ever re-torque the head?
Click to expand...
The top end/head has not been touched. I'll take a look at the tach seal, but I would tend to think I would see this surrounding the cable fitting as well
 
MrMoonbeam72 said:
Sounds like you're telling me even if these were dangling everywhere, the issue is either on the bulb and socket end, or the other end to wherever they lead to. Nothing to do with how they are pushed in or mounted - i'll dive in :)
Click to expand...
Correctly interpreted from what Rob said. The rubber boots on the sockets are just to hold them in the gauges, nothing to do with insulation.
 
MrMoonbeam72 said:
The top end/head has not been touched. I'll take a look at the tach seal, but I would tend to think I would see this surrounding the cable fitting as well
Click to expand...
If it's the head gasket, and it very well could be, retorquing it is unlikely to stop the leak but it's worth a try. The seepage generally comes from these areas of the head gasket when it's leaking, and these are the areas I always use a little sealant on.

450 head gasket sealer.png
 
And don’t forget to get the LED conversion pigtail.

LED instrument lights don’t help much but the charging system is so marginal that if you all bulbs, is a overall improvements and an even better benefit is brighter lights!
 
Signal updates:
I removed the rear flashers and rewired them to accommodate a separate dedicated ground. Former aftermarket signals were fully removed so I'm back to the stock look :)
As for the fronts, I currently have replicas in place.

I was able to source the OEM stock metal shells from a local with spare parts, but the lens cover was missing on one, and both are lacking the innards including the socket itself.
After a bit of fabrication I was able to remove the insides from the replicas and mount them into the original shells.
A hole drilled in the right spot allows it to sit correctly.
Luckily the replicas lens covers fit just fine (albeit without a gasket). Soon to be mounted in the front...

If anyone has any ideas of how to accommodate a gasket I'm all ears, but frankly I dont expect to ride this in anything resembling wet conditions so I'm not sure how critical they are.
Can anyone provide an ebay source for those LED pigtails? Still cannot get LEDs to work in both front and back, so it looks like that will be needed, despite having replaced the flasher relay

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far left - stock with replica insides fitted in (hole drilled to allow screw)
top - replica (note the lack of hole)
bottom - empty stock metal shell
far right - empty replica plastic shell

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I also had a minor update replacing the triple center nut
The old one had badly corroded chrome.
Also also have shiny fork top bolts to replace the existing dechromed ones

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