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1974 CB450 - maintenance, repair, and upgrade log

I've been slowly working on painting the tank and covers for my CB450 over the last year. This tank was a spare that I bought several years ago and the covers come from my parts bike, so I still have a set of black covers and a black tank that I can swap with these. I initially put off clear-coating the paint, wet sanding, and polishing last fall, but worked those steps in here and there over the summer. I think there's still a bit more polishing to do, but I had the bike out today and took a few pictures, so I thought I would share them in this thread.

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My clutch cable routing is not according to Hoyle, but, since it seems like the cable has to go around the carb insulator either way, I've never changed it. Is there a good reason to route it on the inside?
 
stl360+450 said:
I've been slowly working on painting the tank and covers for my CB450 over the last year. This tank was a spare that I bought several years ago and the covers come from my parts bike, so I still have a set of black covers and a black tank that I can swap with these. I initially put off clear-coating the paint, wet sanding, and polishing last fall, but worked those steps in here and there over the summer. I think there's still a bit more polishing to do, but I had the bike out today and took a few pictures, so I thought I would share them in this thread.

My clutch cable routing is not according to Hoyle, but, since it seems like the cable has to go around the carb insulator either way, I've never changed it. Is there a good reason to route it on the inside?
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Did you do the stripes too? It looks good, I like the color. No special reason to route the clutch cable on the inside of the carb except that it's there from the factory (and IMO looks better behind) but since you have a black cable on it, it isn't as stand-out visible as it would be with a gray cable.

Hard to believe your summer is over already.
 
ancientdad said:
Did you do the stripes too? It looks good, I like the color. No special reason to route the clutch cable on the inside of the carb except that it's there from the factory (and IMO looks better behind) but since you have a black cable on it, it isn't as stand-out visible as it would be with a gray cable.

Hard to believe your summer is over already.
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The tank stripes are from 4-into-1 and went on fairly easily. They have black or gold stripes. The paint is House of Kolor: Galaxy Gray over Lime Gold. I can get rattle cans made up at my local supplier of SprayMax 2K clear.

It's good to know that the cable routing isn't making a functional difference.
 
After watching my CB360 fall over on the center stand last week (due to soft asphalt), I've been reevaluating my center stand preference and I found something troubling with my CB450. Last November, I swapped out my old, bent side stand for the spare from my 1972 CL450 parts bike as part of replacing my swingarm bushings and tidying up the centering of my center stand. With the bike on the side stand, I found that I could easily nudge the bike forward enough that the side stand would fold up, which would obviously allow the bike to fall over. I tried putting it in gear and there was still enough free play to cause this to happen. The side stand position is shown below. I think I would feel better about the side stand if it rotated a bit more, so the foot would be farther in front of the pivot point. I guess this is why it is important to put the bike in gear when parking on the side stand, especially in a public parking situation.

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Actually, the picture on the left above shows the correct sidestand spring installation, the elongated end is designed to clear the pivot bolt head. I know the parts fiches aren't always indicative of proper assembly but in this case it is.

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If you wanted the stand to be less likely to roll forward past the point of folding up, you could remove the stand and grind some metal off the frame's stopping point for the stand to increase the forward angle when it's down, and the further past center the spring goes the better it will help keep the stand down.
 
ancientdad said:
Actually, the picture on the left above shows the correct sidestand spring installation, the elongated end is designed to clear the pivot bolt head. I know the parts fiches aren't always indicative of proper assembly but in this case it is.

If you wanted the stand to be less likely to roll forward past the point of folding up, you could remove the stand and grind some metal off the frame's stopping point for the stand to increase the forward angle when it's down, and the further past center the spring goes the better it will help keep the stand down.
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I see you are totally right. I think I was looking at the spring on the center stand in the fiche I consulted.

I like that idea of grinding a little metal away to achieve a greater rotation angle on the side stand. This is something I could experiment with using my spare, untitled CL450 frame, too.
 
Last year I ended up swapping out the original spark advance mechanism with one from my 1972 CL450 parts bike. I had disassembled the original and was hoping to shorten or replace the springs and accidentally snapped the e-clips. The advance mechanism from the parts bike also seemed to have weak springs, so I shortened both springs slightly and I have been feeling that the timing was off at low RPM, especially before the motor has fully warmed up. It feels like the advance is reluctant to open and then opens suddenly at a certain point, rather than opening smoothly as shown in the manual.

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So, this spring, I went through a mini-tuneup and adjusted the valves and static timing to see if the situation would improve. The timing was slightly advanced, but the cam/follower clearances were all at about 0.002", so no red flags there. Also no change in behavior after the adjustments. I then ordered an advance mechanism on eBay listed for 450/500T and realized after I got it that it was the TEC375 model for the 500T. Thanks to @Jays100, who confirmed that the TEC375 is compatible with the CB450s, I just installed that advance mechanism and the bike is running much better — the engine speed increases smoothly from idle on up with no hesitation as the advance mechanism opens.

I am waiting on a small order of tension springs from eBay with the ultimate goal of finding suitable replacement springs for the 450 advance mechanism. I probably won't hit the bullseye on the first order, but I will try to keep at it until a suitable replacement is found. This time I more or less made guesses based on a few caliper measurements, but I'll try to be more scientific about it going forward.

I had the 723B carburetors off for the valve adjustment and thought I may as well document things here for later reference. The float heights were 22mm (left) and 21mm (right), so I reset them to 20mm.
  • main jet: 145
  • pilot jet: 38
  • slow jet: 38
  • float height: 20mm
Another odd thing was that I noticed a slop in the shift lever while riding and found that the bolt on the back of the lever needed to be tightened. I checked my other bikes and it was still tight on my CB360G, but also needed to be tightened on my XL350. I should have paid more attention to that.
 
stl360+450 said:
Another odd thing was that I noticed a slop in the shift lever while riding and found that the bolt on the back of the lever needed to be tightened. I checked my other bikes and it was still tight on my CB360G, but also needed to be tightened on my XL350. I should have paid more attention to that.
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It's actually pretty typical for shift and kickstart levers to work loose a little bit now and then, it was one of the many little things my father taught me to periodically check along with other fasteners because of vibration. When you let them go too long it begins to wear the splines and it can lead to bigger problems, of course.
 
Two weeks ago, in the middle of my 4 mile commute to work, my CB450K7 lost all power. It was a pretty calm city street and I pulled off onto a side street with no traffic. I was surprised to find that all electrical was out — no neutral indicator, no headlight, and definitely no power to ignition. I checked the main fuse — it was fine. A short time later, I remembered that the aftermarket charging system had a separate fuse — also good. I did not have a multimeter handy and needed to get to work, but, fortunately, had left home a couple of hours before any serious responsibilities demanded my presence. Long story short, my bike had its first professional tow that morning and I barely made it to work on time.

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I like to figure things out myself when I can, but haven't had much time to do so since this happened. However, I set aside a couple of hours this afternoon for testing and came back inside after five minutes. I was pretty surprised by the point of failure as well as the fact that I didn't notice it on the day it happened.

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This is another learning moment for me. A fifty year old ground cable failed due to fatigue — I should not be surprised. Still, I'm thankful that it wasn't something more serious.
 
ballbearian said:
If there's enough left to just drill another hole in it, that would be too wonderful.
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It looks like there is, so that is definitely a possibility. I believe I also have another fifty year old specimen on my parts bike. This part seems to be NLA, but I would think there are new parts available that could do the job. Otherwise, I might make one.
 
stl360+450 said:
It looks like there is, so that is definitely a possibility. I believe I also have another fifty year old specimen on my parts bike. This part seems to be NLA, but I would think there are new parts available that could do the job. Otherwise, I might make one.
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Did you send me the one off of your parts bike when you sent the wiring harness?

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stl360+450 said:
I may have. I think I also have an extra from one of the 350 projects, but, honestly, I just ordered materials to make a new cable. So, I should be fine.
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Gotcha. I would have had no problem sending it back. I randomly noticed it in my extra parts bin a month ago. Could never figure out where it came from lol. I am curious what it takes to make one of those thick gauged wires.
 
Danager4792 said:
Gotcha. I would have had no problem sending it back. I randomly noticed it in my extra parts bin a month ago. Could never figure out where it came from lol. I am curious what it takes to make one of those thick gauged wires.
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Apparently, a hammer crimping tool!
 
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Danager4792 said:
Did you send me the one off of your parts bike when you sent the wiring harness?
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I think I'm going to use one from a 350 while I wait for the cable materials. I measured the spare I have at about a foot (31cm). Would you be able to tell me the length of that extra ground cable you have, Dan?

(Not too send back, just to see if this cable I found is going to be long enough.)
 
Home depot or Lowes has #4 wire and copper eyelets that can be swagged with a punch (I solder mine too). Autozone, etc. also have eyelets in the battery accessories aisle, get one 1/4" and one 3/8" which will fit the 8mm frame bolt and the 6mm battery connection. Or just buy a car battery cable and chop the fat battery post fitting off and use the 1/4" eyelet.
 
ballbearian said:
Home depot or Lowes has #4 wire and copper eyelets that can be swagged with a punch (I solder mine too). Autozone, etc. also have eyelets in the battery accessories aisle, get one 1/4" and one 3/8" which will fit the 8mm frame bolt and the 6mm battery connection. Or just buy a car battery cable and chop the fat battery post fitting off and use the 1/4" eyelet.
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Thanks, Tom. I have an eBay knee-jerk reaction in these situations, so a few things are already on the way and I plan to use the 350 ground cable in the interim. I only ordered 3/8" eyelets, so should probably pick up one/some in 1/4".
 
stl360+450 said:
Thanks, Tom. I have an eBay knee-jerk reaction in these situations, so a few things are already on the way and I plan to use the 350 ground cable in the interim. I only ordered 3/8" eyelets, so should probably pick up one/some in 1/4".
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I bought a 12' set of WallyWorld jumper cables and some eyelets for my van inverter for less than half of other cable by the foot, then whacked off the jumper clamps. Even #8 cable would be fine.
 
This bike shows up occasionally at school and was there when I was leaving — it belongs to a student. I hadn't been aware of 4-stroke triples until I spoke with him about it a couple months back.

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Yep, Yamaha got into the superbike wars with that one and while it may have been a nice reliable bike it was average competition for the other 750s and 850s, similar to the performance of the XS1100 4 cylinder they also had compared to other manufacturers' bikes in that era. Cool to see one still around though.
 
I finally have all of the little things I needed to make a battery cable: wire, lugs of two different eyelet sizes, heat shrink tubing, and the anvil crimping tool. So, today, I made a ground cable. I think I'll do a little better the next time, but this should be a usable cable. I like that it is more flexible than the OEM cable.

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I continue to experience new things through routine maintenance on my small collection of vintage bikes. Several months ago, on a longer ride, I started experiencing some chatter from the drivetrain when starting from a stop. I had felt something similar when my rear chain was loose and checked that as soon as I got home. The chain tension checked out normal. Since most of my rides are fairly short by normal standards (my work commute is 8 miles round trip) I didn't experience this symptom again until the next longer ride of about 30 miles total. It was worse than before and prevented me from taking off quickly from a stop — I would engage the clutch gradually to get started as smoothly as possible. I suppose it makes sense that worn plates perform worse when the motor is hot?

I looked at my records and found no evidence that I ever changed any of the wearable parts in the clutch through 13 years of ownership and 5,000+ miles of city riding. Adding in an unknown prior history and the recent clutch chatter, I decided to change the oil and replace both the friction plates and the steels.

I had it out for about a 7 mile ride today for the bi-annual safety inspection. The clutch felt like it should and I continue to enjoy the 16-tooth front sprocket.
 
There is a very helpful thread on CB450/500T advance mechanisms started by @Jays100 and I've been following that with interest in sourcing replacement springs. Jay provides some nice tips there about cleaning/rebuilding an old advance mechanism and shares a specific spring from McMaster-Carr that he has put into use. I had tried clipping stretched out springs on one of my old advance mechanisms, then swapped in another one from my parts bike, and ultimately ended up with a used advance mechanism from a CB500T. The 500T advancer works fine, but I have been wanting to try my hand at rebuilding one with new springs for a while since it's a common problem and good used or NOS advance mechanisms are getting harder to find.

The mechanism I rebuilt came from my 1972 CL450k5 parts bike and was sticky due to a build-up of gunk over the years. Jay's tip to go at all of the moving parts with Scotchbrite worked really well.

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I bought an NOS CB450 advance mechanism for my strategic reserve and used some simple caliper measurements to order a few sets of metric extension springs from an eBay seller. The next photo shows a comparison of one of the springs I bought with the spring found on the NOS advance mechanism — it's a reasonably close match. I assembled the rebuilt advancer with a set of new springs and set of generic 4mm e-clips.

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I was only looking at metric springs and found that available lengths start at 15mm and increase in 5mm increments. The 15mm springs I tried had small hooks and I didn't like how they stretched during installation, so I ruled them out. For comparison, I believe the spring Jay is using has a length of 5/8" or 15.875mm — that last 0.875mm might make a big difference. The 20mm springs are available with outer diameters ranging from 3mm to 8mm. With an outer diameter of 6mm, the wire diameters can be chosen from 0.6mm, 0.7mm, 0.8mm, and 1mm. I bought packs of the 20mm/6mm combination with wire diameters of 0.7mm and 0.8mm.

Today I installed the advancer with the 20mm/6mm/0.7mm combination and did a few laps up and down the street and around the block as the bike warmed up. The bike seemed to accelerate smoothly and at the end of my testing the motor was still returning to idle nicely. If anything, they may be a little soft, but I think I'll put some more miles on them before trying to bump up to the 0.8mm wire springs. I will also plan to order the 1mm wire diameter for later testing. If I continue to feel good about these after further testing, I should probably get out the timing light and see how things look from that angle.
 
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I'm working on repainting my tank and side covers. Last year I tried to reproduce Candy Bacchus Olive with marginal success that was negated when a big chip came out of the paint on the tank. I think it was caused by a ratchet strap when my battery ground failed and I had to get the bike towed home.

One of the cover emblems was missing a post and I fashioned a new one from a roofing nail. I used JB Weld to attach it to the emblem and that ended up failing. I then used Loctite Stick 'n Seal and that held up well. Unfortunately the remaining original post gave up the ghost, so I replaced it with a roofing nail this afternoon.

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The post at left was freshly glued, the one on the right shows a mixture of leftover JB Weld and the Loctite product. I learned about the Loctite product from a post by @LongDistanceRider about VIN plate removal and reinstallation. Thanks, Jim.
 
My CB450K7 came with a plain black paint job on the covers and tank with no decals. After one season in faux Candy Bacchus Olive, I'm going with a single-stage color: Duplicolor Brilliant Black Pearl (Chrysler). The K3—K5 tank decals are available in black or gold (4-into-1, Diablo Cycle) and there is a white on gold version from CBDecals.com along with another option, maybe gold on red.

I was interested in a white decal with no gold, so I contacted Diablo Cycle today and they are willing to produce a white decal as long as I order two sets — they print two sets at a time. Sounded fair enough to me, so I agreed.
 
I figured one can of SprayMax could handle three side covers and combined the two here with the one for the CB350.

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I also started prep work on the tank. Not a pretty sight. I'm not fond of using the aggressive paint strippers to take a tank down to bare metal because it seems to take forever and makes a big mess. So, this time I'm avoiding that hassle. Hopefully I won't regret it.

I used a flap disk to remove the decals, exposing striations of the coats underneath. Then I used 400 grit paper, first dry and then wet to smooth things out before I reapply primer.

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I hope the next picture of the tank will show improvement.
 
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stl360+450 said:
I'm not fond of using the aggressive paint strippers to take a tank down to bare metal because it seems to take forever and makes a big mess. So, this time I'm avoiding that hassle. Hopefully I won't regret it.
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There is no such thing as aggressive paint strippers ever since they took the good stuff out. At least for consumers.

I’ve had luck with the sissy Citrus Strip. Key is thick, and wrap it in Saran Wrap. Come back at least 12 hours later. Scrape and wire brush.

Plus it smells like oranges.
 
They strip paint off metal well; be gentle on aluminum, maybe use a finer grade of abrasion. They do wear down slowly over time and you have to be careful to use them so they do their work going off edges. If you run them going on to an edge you can rip the bristles out and they hurt when the hit your legs. I've ground paint down to the steel on several Honda products, and even took paint off plastic, but that takes a really light touch, probably better if you use a finer grade. I bought some Roloc disks that were Ebay knock-offs, and they were terrible, didn't really work. As the 3M ones wear down the bristles get shorter and shorter, but they also are stronger when they are short, and last longer. I have 2 that are now about 1/4" stubble, and they still work some on smooth surfaces. I understand it's a pricy thing to experiment with, but it does work well.
 
I should be receiving the custom white CB450 decals tomorrow from Diablo Cycle and I was hoping to finish up color paint on the tank today. I am still doing some wet sanding to smooth out blemishes that stem from the removal of the previous decal and things were going well until I tried to add fresh paint today after a thunderstorm. I thought the humidity had dropped, but, if it did, it wasn't enough to make a difference. I was immediately reminded of @boddy's experience painting a headlight bucket, which is really the first time I had seen the appearance of a paint change so drastically after drying. The picture below shows an area towards the front of the tank that I was spraying today with Duplicolor Brilliant Black Pearl. Not black, not brilliant. I will have to paint on another day.

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I had it happen with some VHT caliper paint (gloss) on my Dream. I finally bought a new can and shook it for a long time which helped a lot. It does make me wonder if some of the paint components don't remain in the proper ratios or proper suspension for very long.
 
ballbearian said:
I had it happen with some VHT caliper paint (gloss) on my Dream. I finally bought a new can and shook it for a long time which helped a lot. It does make me wonder if some of the paint components don't remain in the proper ratios or proper suspension for very long.
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I was a bit skeptical about the effect of humidity and wanted to think that there was something wrong with the can(s), but my experience this time has convinced me not to mess with 60% or higher humidity. It seems to have something to do with the ability of moisture to condense in the fresh paint, so I'm not sure if there is a way to prevent it with a rattle can.

Yesterday I squeezed the last dregs out of two cans that were mostly used up — saw some blushing and blamed it on the fact that the cans were nearly empty. The paint did look normal as it laid down on the tank initially.

Today I started with a fresh can and it looked good as it went on. However, after only a few minutes of dry time, there was the blushing again. I had waited until the weather app humidity forecast was around 60%, but I'm sure the local humidity where I was painting was higher based on how it felt. Once I thought about it for a few seconds I knew it was not going to work today.
 
Decals arrived today. Now awaiting less humid weather. I did wet sand the blush with 1000 wet/dry and that definitely helped, but I'd still like to get another coat on top of that before applying the decals and clear.

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Tracking for low humidity shows little hope of delivery this week.
 
I did manage to find a short window of lower humidity to finish the paint. And now I have installed the decals from Diablo Cycle. I'll wait another 24–48 hours and then I'll spray the clear when the humidity cooperates.

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The last time I applied a decal I ignored the suggestion to add a bit of dish soap to the spray bottle. This time I put two drops of Dawn in a roughly 8 oz spray bottle and it seemed to make everything go more smoothly. I was prepared to use a plastic tool to work out bubbles or wrinkles, but I was able to deal with the tiniest bubbles that appeared just using my fingers.

I probably could have aligned the two decals a little better, but I am pleased with the result.
 
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