'73 CB450 Restoration - Lots to learn!

crywolf

New Member
I've decided it's time for me to start a log here. This weekend I began working restoring a '73 CB450. This is my first attempt ever at restoring anything so I have lots to learn. I am more than accepting of any advice or recommendations you guys make towards the project.

Background:
My uncle and grandfather bought the bike used around 1980. They both rode it for some time and eventually the bike was parked in 1984. Thankfully, my family is very good at holding on to older things and luckily this bike was stored in my grandparent's garage since the day it was parked. As far as they remember the bike was running when it was parked. For the most part, it appears that the bike is in very restorable shape.

Here is where the bike has sat since 1984. There is a roof covering it so for the most part it has been out of the weather.
DSC_0408.jpg


This is the starting point of the bike. It came with so many great accessories like the humongous windshield, the sissy bar, and the luggage rack. All of these accessories have since been removed.
DSC_0421.jpg


Another shot of what I'm starting with. If you look at the ignition you will see that he was able to find the key to it. Surprisingly enough, it only took my grandfather and grandmother about 5 minutes to find a key and title for it.
DSC_0426.jpg


Picture of the bike without the windshield and after quickly rinsing off the dirt/dust.
DSC_0515.jpg


The gauges and gauge covers are in great shape.
DSC_0544.jpg


Finally, this is the best shot I have after the cleanup and accessory removal.
DSC_0549.jpg


I need to get some updated pictures. I have removed the gas tank and seat to give me some working room. The gas tank is lightly rusted on the inside so I'll have to take care of that soon. The seat is in great shape. After I clean it up it will be going back on the bike. I've started sorting out the electrical parts of the bike. After adding a new battery and turn signal relay, I've managed to get all of the turn signals working and flashing. My advice is to clean every rusty ground on the bike before anything else. The headlight works. The electric starter works intermittently however I haven't spent much time to understand it yet. I have a long ways to go but so far so good.

Let me know what you think of the project and please do not hesitate to make any suggestions on best methods for troubleshooting, diagnosing, or just general knowledge of the bike.
 
Congratulations on starting your first restoration Brother! You could not have chosen a finer motorcycle and the fact that it has family history will make it even more special and sentimental!
 
My grandfather actually seemed pretty excited about getting it running again. He was pulling it out of its resting place before I could get to it. The man is 83 is will still out work me any day.
 
That is really cool Brother, I am sure you will put a smile on his face by restoring her!
 
Update:

After debating rebuilding the stock airboxes, I just decided to start with the unifilter air socks.

The inside of the tank had some light rusting and wasn't too bad. I did red-kote the inside of the tank just to prevent future issues. I have a new gasket for the petcock arriving later this week along with gasket rebuild kits for the carbs. I'm curious to see the inside of these carbs considering the bike has been run in 28 years.

I do have one question regarding the electric starter. If I put the bike in neutral, pull the clutch lever in, and press the start button the electric start makes a sound. Without pulling the clutch lever in nothing happens when the button is pressed. Is this normal?

Other than that I have the petcock cleaned and working. I cleaned a lot of rusty bolts this weekend. I was surprised how effective plain white vinegar was at this. I also purchased new fuel lines from the local Honda dealer to replace the brittle old ones. I'm hoping to get the carbs rebuilt later this week and give the engine a go.
 
The project is progressing.

I have rebuilt the carbs. Surprisingly the carbs were extremely clean on the inside. The pictures below led me to believe the inside would be nasty.

IMG_2657.jpg

IMG_2658.jpg


With the carbs finished, I had hoped to get the engine running this past weekend. Friday night, I checked the engine for spark and was unable to get the plugs to ignite. Here is where I need help. When checking for spark, I pulled the plug, connected the plug wire and touched the plug to the engine. I was unable to get a spark using the elec start. The wire running to the coil assembly is black with a white stripe. Inside the headlight bucket, I took the joint from the switch and the coil assembly apart to test for current when starting the bike and was unable to measure a current. I am assuming the problem then lies in the switch.

Does this make sense to anyone? Am I correct in my testing method?
 
Do you have a multimeter? If so, you should be getting 12V when reading between the black/white wire and the frame. If you are getting power, then it's probable that one or both coils are bad.

If no power, check to make sure the kill switch is set to on. If it is, you'll want to repeat the multimeter test using the black wire that goes into the kill switch and the frame (make sure you have the correct black wire, there are many of them. The one you're after should come from a connector in the headlight bucket with the source of that connector being the ignition switch. Keep repeating this test for every junction back to and including the ignition switch. When you find power, you know the fault lies with the last thing you tested.

Of course, you can test in reverse as well. Start with the red line leading into the ignition switch and follow the black line coming out.

To test the coils themselves, run 12V into the black/white wire while the blue or yellow wire remains grounded. Get a buddy to hold the spark plug wire (with plug installed) up against the frame or engine case (bare metal) and the unground the blue or yellow wire and you should see a nice fat blue spark.
 
@Sonreir: Thank you very much for the post. This is definitely the guidance I have needed. I'll have time tonight to work through all the guidance you sent.

Here are my initial findings.

I do have a multimeter. I have no power between the black/white wire and ground. The kill switch is set to on.

Just to make sure, the kill switch is on top of the right-hand control and reads Off/On/Off?

I'm going to work through the rest of the wires tonight.
 
crywolf said:
I do have one question regarding the electric starter. If I put the bike in neutral, pull the clutch lever in, and press the start button the electric start makes a sound. Without pulling the clutch lever in nothing happens when the button is pressed. Is this normal?

No this is not normal. The starter should spin when you press the button wether the clutch is in or out or even if the bike is in gear. Ask me how I know. :)
 
@Flugtechnik: Thanks for the comments. This problem I was able to get solved. My bike wasn't trying to start without pulling the clutch in because the handlebars were not properly grounded. I ran a separate line from the handle bars to ground and now it will try to crank without pulling in the clutch.
 
I was able to look at the wiring more at lunch. Let me first state, that the only light currently not working on the bike is in the tachometer gauge. I verified that power is going to it so I believe the bulb is just burned out.

I checked all of the black wires leading into the headlight bucket from the ignition switch. All of the incoming black wires had power. One odd thing is that there is a black wire in the headlight bucket with power that doesn't connect to anything. It has a 4-point female plug end. I didn't see any other disconnected wires except for a brown wire which appears to be expected from the wiring diagram. The brown wire doesn't have the correct plug to go into the black wire. It seems like power is running to the right hand controls but for some reason no power is being returned down the black/white wire. I tried measuring the black/white wire with the Kill switch in all three positions. All other electric parts in the right hand controls work. Headlight and dimmer switch work.
 
You will occasionally find female connectors with nothing in them. Normally not something to worry about.

If the black wires in the headlight bucket are energized and the black/white wire is not, no matter how you position the kill switch, then either the switch is bad or the wire to or from it are bad.

To temporarily bypass the kill switch for testing you can plug the male end of the black/white wire into the open female connector on the black wire.
 
Good news! I was able to get this issue resolved. Turns out the issue was with the two electrode posts which the kill switch is suppose to connect. For those unaware, the kill switch has a powered solid black wire carrying power to this area. A black/white wire then returns the power down the handlebars and to the coils. I believe the bb under the kill switch wasn't allowing current to pass through due to the posts being so corroded. Testing with the multimeter proved power was getting carried to the kill switch but now being transferred to the black/white wire.

Other updates, I jumped the black/white wire in the headlight bucket to the empty powered black female wire in order to test the coils. I was able to get spark on only one of the plugs. I tried switching plugs and wires to verify the second plug was bad but it appears one of the coils is bad. I'll be ordering new coils this weekend to rebuild the whole coil assembly. I'll replace the condenser for good measure.

Marching on..............
 
Back
Top Bottom