Honda CB450, first motorcycle restoration

Hey everyone!

I just bought my first motorcycle ever for a restoration project, and I know nothing about it so this seemed like a good place to start! It's a '69 Honda cb450 that has sat for 25 years without running. The guy who sold it too me said it has been completely "locked up" that whole time, and we had to carry the bike to get it into my car as the rear wheel wouldn't turn. Overall, it seems like it will serve as a good base for a restoration as there a ton of critical rust. I've restored a number of cars, but never a bike, so here we go...

So day one is over, and after about 6 hours I've gotten as far as the complete tear down of the bike. I haven't opened the engine yet, that will be this weekend. I discovered that the engine cranks over just fine! it was the rear brake that was locked up.

You can see from the last photo that I have put all of the parts into various boxes. Most of the body parts, brackets, frame, etc. will go to the powder coater for a fresh coat of black. There is a box that will be re-chromed, which is mostly fenders and a few misc. parts. Ideally I will replace all of the electronic parts, but will hold onto the old ones untill I find replacements. The rest of the parts will I will have to refurbish myself. I intend to replace as many parts as possible with new/modern equivalents. I want to keep the bike somewhat original, but I prioritizing creating a reliable, long lasting motorcycle.

Here are the questions that have come up already:
1. I see that you can replace the regulator and rectifier with a modern single unit. Which parts are the regulator and rectifier? I can't identify them! (the clymer manual is on order...)
2. Headlight lens: is there a modern replacement for this?
3. Suggestions for mufflers, exhaust systems? Stainless would be nice...
4. Is it possible to upgrade the front brake to disk? I see that '70 450s have a disk, so I imagine this is possible?
5. Any recommendations on a color scheme? I am mostly wondering what parts should be black and what parts should be chrome in order to give the best balance? I was thinking the hubs/drums and rims should be black with the spokes polished stainless? What about the forks?
6. Any concerns/considerations before I crack the case open?
7. I see that most folks are switching to cone style air filters. I like that option a lot, but I am wondering if I can still use the side covers...
8. Do all Honda cb450 frames look like they were stick welded by a drunken toddler? I removed the battery box, but it took a ton of grinding in order to get the seat brackets off as they welded over the top of everything else. What gives?

Any other suggestions from folks who have been around the block would be greatly appreciated...

That is one crusty bike. You have a lot of work ahead of you.

I will try and answer what I can.

1) The regulator and rectifier would have been mounted to the battery box. The regulator is a small silver box and the rectifier is probably some odd red finned thing. If wiring isn't your thing, a member on here, Sonrier (sparckmoto.com), makes new wiring harnesses with new reg/rects.




2) Likely. If you are looking for one to fit the stock headlight bucket try checking Dime City Cycles.

3) ?

4) Yes, it is, but it is probably not as simple as it first appears. You will need to get newer forks with a caliper mount and the new forks won't fit in your triple-tree so you would basically need to replace the entire front end. Also, from what I have heard, the 450 disc brake wasn't much more effective than the drum. When setup properly, the double leading shoe drum stops the bike pretty well.

5) Not saying you should copy mine, but you can see if you like it. Rims are black with brushed spokes and hubs. Hub Centers are black. Engine is black with brushed fin edges, covers and engine mounting plates.




6) Not really. It is an interesting engine technologically with the torsion bar valve springs. It is good to review the manual first so you know what you are looking at as you take it apart. There is also a wealth of technical knowledge of these bikes on Hondatwins.net.

7) From my understanding, these bikes work best with their stock air-boxes, if you are going to use the stock carbs. My bike didn't come with one so I ended up using the UNI filters. The cheap pod filters don't work worth a shit. The UNI filters come with standoffs so you can still use your sidecovers. Or you can make your own connection between the two covers to replace the airbox mounts.

8 ) Yes, sadly yes.


You are going to want to replace every bit of rubber in that engine that you can.

Some of the smaller parts and seals/orings are still available from Honda so it's always good to check there for parts first.

Lots of people upgrade the stearing stem bearings to tapered bearings from All-Balls.

Also, lots of people upgrade the swingarm bushings to bronze bushings.

thanks for the reply! tons of good info there. I will continue to post photos as I move along in the project and will likely have many more questions. I definitely plan to replace ALL rubber/gaskets/seals on the entire bike. I will be using new sealed bearings in both axles and tapered bearings for the headset like you recommended. The brass bushings look sweet, I will definitely do that as well.

Do most shock sets come with bushings or will I need to source those as well? Are there any good aftermarket sources for front/rear springs?

I'm an electronics guy for sure, much more than a mechanical guy actually. I plan to make a whole new wiring harness from scratch. I also am interested in the combination regulator/rectifier units, as well as the electronic ignition.

Dose anyone have recommendations for brands/sources as far as replacing the electrical components?

I'm a little concerned about just polishing the aluminum, rather than coating it. I think it looks great, but how long will it actually last before it starts to corrode?

My bike came with rigid telescoping tubes over the forks, and I am not a fan. I am assuming I can just place them with rubber boots and no modifications?

Oh yeah, I forgot one last thing: the shaft that the rear brake lever is attached too was bent such that it could not be removed from the bike or separated from the lever. Is this normal? I hope not, because I had to hack it apart to get it off.

something like this for the air filter?

http://www.ebay.com/itm/All-Honda-CB-CL-350-450-Twin-Uni-Filter-Replacement-Air-Filter-NU-4001-/310434656629?pt=Motorcycles_Parts_Accessories&hash=item484758f175

There is no way I can reuse the original air filters. Is this the next best option?

That is what I have on my bike and I have heard other good reports about them. What I was referring to was to use the original airbox with new filters if it is possible.

I did not leave any metal bare. All of the brushed aluminum and steel I have on my bike was painted with a high heat clear enamel. It has yellowed slightly since I painted it a few years ago.

The brake pedal shaft is supposed to be straight but I have seen a few damaged ones. Mine was bent badly. I bought a straight one off ebay from someone parting out a bike.

When I bought a pair of shocks, it came with the bushings and a spacer in case the bushing ID was too large. It was not.

For fork springs, try Progressive Suspension or Forking by Frank. Also, a member on here, beatnic at DEK Performance, does a lot of suspension work and could probably help you or point you in the right direction.

You should be able to replace the covers with rubber boots (sometimes called fork gators). They are usually just held on with clamps.

You are going to have such fun.

On the wiring loom, I'd avoid starting again if you can help it. I did and it took mountains of time to get it all done. In hindsight I should have just fixed what I had - and I have an electronics background. I won't do it again unless I really have to.

If it it really bad, I'd recommend buying one of Sonreir's looms (Sparck Moto).

So glad the seize issue was just the back wheel. That must be a huge relief.

I'm in for the journey,
D.

Okay, I finished the engine tear-down last night. I'm not sure if has been rebuilt ever, but has honda pistons still. There are some things about this engine that are really cool! I love the planetary gears for the starter reduction (although I can't figure out how to get the ring gear out)! I didn't find any major concerns, but definitely a few small things.

1. the screw that holds the shifter star/indexing thing to it's shaft was almost completely unscrewed when I took the cover off.
2. there are a few small nicks in a couple of teeth on one of the cam shafts.
3. there is a fair amount of corrosion on the crankshaft, rod, and camshafts.
4. The cam followers are very worn down.
5. the cylinder head covers that hold the camshafts look worn/scratched on the races(is that what you would call them? or bushings?)
6. the rubber cam chain dampeners on the camshafts are obliterated (yikes!), and the plastic cam chain sprockets are mostly all shot.

Here are some photos (they are pretty bad, sorry):

My clymer manual showed a few days ago; it's super helpful. I did notice something strange though. My front fork configuration does not match that of any of the diagrams in the manual. I identified that my bike is a CB450 K3 based on the VIN plate, but the fork configuration most closely matches the CL model. The bike came with rigid fork covers rather than flexible boots, and has a single external spring and no internal springs.

I have 2 concerns about this: first, I want to use rubber boots, not the rigid tubes which look way less classy and probably aren't as functional, will the boots fit over extern springs? Second, I can only find replacement springs for internal type forks, is it possible to convert mine or will I need new inner fork tubes? Any thoughts on this would be greatly appreciated...

From looking at the diagrams in the Clymer manual, it appears that my fork tubes (which use the external springs) are very similar to the internal type fork tube. The only difference that I can see is a small disk that has been inserted at the bottom of the tube on my forks. I am wondering if I can just remove this disk and then use the internal type springs. I have attached some photos of my fork tubes, maybe someone with internal springs can take a look and tell me how they compare? I am assuming the outer/bottom fork tube is the same on all models?