1973 CB450 - First Bike, First Build.

jamssauce

New Member
Also posted on hondatwins.

After much lurking it's time for my contribution! So, a little about me:
- my first bike
- my first build
- small handful of mig welding & fabrication experience
- 24 yrs old
- engineering student (access to some cool tools)
I purchased this 1973 Honda CB450 in March 2013 for $800. Took a few longgg breaks on this build in the past year, but now the goal is to finish before July 15th. I apologize in advance if the following photos are all over the place; Most of these photos have been collected in the past year I've worked on and off on this build. I tend to work in random spurts, and jump in between projects a lot (also work on a 240sx s14 from time to time).




An ambitious (read: idiotic) project for my first rebuild. Pretty sure I over paid, and I certainly abhor rust with a passion now.

Makeshift wooden mount for the motor


Attempted electrolysis for rust removal. Results were unsuccessful -- I think because there was just SO much rust. Perhaps results fair better if you execute it a few more times with more annodes to collect rust.


I will try again to remove only the internal rust this next time.


Paint stripper. Used the citrus home depot gel, but henceforth will only be using aircraft remover as it is much quicker. The Citrus home depot gel required a few sessions to remove everything completely.


Among my first ordered parts: Mikuni carbs, Shorty GP clutch lever&perch, Mikuni 2-1 throttle cable
 
Early assessment of the motor.





I tried to wire wheel/paint stripper off all the frame paint. Fail. Never again, will always media blast from now on!


Tried to fab my own oil filter housing lock nut socket (not pictured). Also fail. Had to order the socket online.


Test fitting this rear hoop w/15 degree upsweep from Dime City Cycles.


Attempted to TIG weld slugs into the rear hoop at school. Fail. According to my boyfriend, a certified welder, our school machines are outdated, thus I was unable to penetrate with enough heat. I apparently needed double of the maximum settings.


Solution: torch slugs + MIG weld



Satisfied with results (although in hindsight I wish I had made it slightly shorter :p )

Since I was already outside welding, I decided to fab up a tail section. Used mild steel rod at home dept. Hand bent with the rods placed in a small vice.




Sheet metal next. 22 gauge if I remember correctly. Unfinished work.
 
Tearing down the motor!





Not pictured, but cam tensioner rollers, valve arm rocker, look good.
First batch sent out for sandblast. Plus frame, 1 rim, and tank (only outside).


Results





Rattle can spray painted the tank gloss black + clear coat. Used glass bondo for dents, sanded it down, then painted. Results came out Okay, but less than perfect is fine by me since I anticipate on some first-bike-drops that will most likely damage my tank anyway.


Rattle canned side and valve covers high temp VHT matte black. I did not cure this paint so my fingers are crossed for durability. These came out nicely, though.


 
Now, these are the current things that require work:
- Hot tank motor after tear down completion
- Finish fabbing the tail

I'm having difficulty with difficulty with the remainder of the motor teardown. The torsion bars have released, but the spring assembly does not pop up.

After connecting with Steve (66Sprint), he was kindly able to suggest a PB blaster soak overnight. Thus I wait, and plan on using a combination of 1/4" extension + 5/16 socket + rubber mallet to gently hammer

Something like this, which I'll try tomorrow:

Does anyone know if these forks too pitted for use? This is after a couple coke + aluminum foil sessions...


Coming from fork seal bottoms that looked like this:


I just ordered loads more of parts. Can't wait.
Any help/advice would be much appreciated!
Thanks for reading this far :p
 
Wow, quite a rough first project. There is a learning curve with making tools and just buying them. Flywheel pullers, locknut sockets ad wheel bear pullers are just a few that are go to get early and always have them when they are needed.

Also, the tail construction is different and it's looking great so far. Keep up the hard work and soon enough it will be to your liking. I just have to mention. Do everything the best that you can and don't skip out on things or else in 6 months or a year you will regret it and do it all over again ( and curse the old you for being impatient). Trust me, I've learned that lesson the hard way and I wish I would have taken my time.

Good luck, I'm following your build!
 
Thanks Drey6! I'll have to add those tools to my list. Yes, I definitely struggle with impatience and rushing things. Hopefully with this build I won't cut too many corners, heh.
 
After an overnight pb soak and the 5/16 socket + 1/4 drive extension + mallet method, I was able to FINALLY get the valves free. The valves were really, really stuck. Even the rocker arm would not budge on 2/4 valves. I ended up damaging one of the spring assembly tubes. Should I replace this?


Devil valves




The other 2 looked worse past the seat. I will lap these after hot tank.

Also, how can I remove this bolt to remove the gearshift? The whole assembly rotates.





This is the last piece of the motor I need to remove to drop off my case pieces for hot tank!
 
coming along nicely
that bolt/screw on the drum is a real buggaboo because many have broken the case trying to use a hammer impact,the case is not real strong there
if it was me i would just drill the head till it pops off safe way to do it
 
Bunch of goodies I ordered from DCC and stainless cycles have come in.

Taking a break from building as the semester nears the end, and I also went to track to drift my 240sx and am back to being broke. Better updates in May, hopefully.
 
Update After a Long Delay

Alright, so I've been back from vacation for a couple weeks now--sorry for the delay. Just recently started back on this project!

Cleaned up the valves. Used a dremel scotch brite type of extension to clean up the gunk, being careful not to touch the seat area of valves. Lapped with suction cup and grinding compound. Lightly lapped each valve and checked for leaks with mineral spirits. Ended up with 3-4 light lap sessions, but the seats on the intake valves seemed pretty decent before I touched anything. Also painted all the motor components and replaced all the valve seals.

Before:


After:







Picked my engine cases, head, and cylinder top from the machine shop where they hot tanked the components; most of the sludge came off, but there was a lot of calcium/lime build up. Machine shop guy suggested I used CLR so I tried so Home Depot knock off version, but did not have much luck. I cleaned off what I could and rattle canned it with engine temp VHT. Really wish I had waited to wire wheel all the gunk off, but only got to properly clean the bottom case (worst grime build up of them all).

Here's what some of the engine parts look like:



Lightly sanded down on the fin parts cause I think it looks cool:



The valve covers are rattle canned with high temp matte black instead of the gloss black like the cases, so we'll see how that combination turns out when the motor is finished. Fingers crossed.

Using these awesome write ups on rebuilding the head (http://www.hondatwins.net/forums/1-project-logs/11792-cb450-cl450-valve-train-assembly-pictorial.html)
(http://www.hondatwins.net/forums/1-project-logs/613-1970cb450-16.html) I've been working on the head. Installing the torsion bars have been OK. I got 3 out of 4 finished, but am waiting on an order from eBay to replace one of the spring assembly tubes I broke earlier. Going to work on the eccentric followers later tonight and hopefully be finished with the head before the end of this week.

Head progress.


Experienced a lot of tension trying to line up the holes to dowel pins on the side -- is this normal? Similar tension on all 3 assemblies so far, so I suppose that just means the torsion bar is working :p

Bad news:
Reviewed my current financial situation. Many parts left to buy (many of these goodies), so due to time + money I will not be powder coating anything. This really sucks and I anticipate a lot of chipped paint in the near future, but I'll have to cut some corners on this build if I want to enjoy this thing before the end of summer! Will likely tear down and powder coat the frame, swingarm, bottom fork tubes, etc. next winter or when I win the lottery.

Many steps left to go, I'll try to post more consistently from here on out. Here is my motorcycle in lil baggies:



I hate rust! :mad:
 
Also...

Tired of grimey bike photos, so here are some new-ish looking things.

Wheel theme is brown rim:



Before going on vacation, I sandblasted the new stainless spokes and nipples. Will be painting these black, and painting the hub black as well.

Can you picture the wheel in your mind? Hoping it will turn out decent with a matching brown seat.

Painted my new top triple tree black (ordered from DCC). Going for a black on black look with brown accents.


 
Holy crap this is one of the crustyest bikes I've ever seen someone try to bring back to life. Nice work so far though. I've never seen black with brown so I'll be interested to see how it turns out.

Are you just going to lap the valves or have the valve seats recut? If you have them recut, you may need to shorten your valves a bit or it may become impossible to adjust them. Recutting the seats raises the valve slightly, and due to the geometry of the cam followers and valves, there isn't much room to play with.
 
i would ad that is is important to not have a valve seat contact width outside the specs as well
as far as the length of the valve that along with the camshaft endplay can be checked with dry assembly of the head on the bench
there is a certain range the valve adjuster eccentrics only work in and like flug is saying too much stickup may get you out if range
 
Flugtechnik said:
Holy crap this is one of the crustyest bikes I've ever seen someone try to bring back to life. Nice work so far though. I've never seen black with brown so I'll be interested to see how it turns out.

Are you just going to lap the valves or have the valve seats recut? If you have them recut, you may need to shorten your valves a bit or it may become impossible to adjust them. Recutting the seats raises the valve slightly, and due to the geometry of the cam followers and valves, there isn't much room to play with.

xb33bsa said:
i would ad that is is important to not have a valve seat contact width outside the specs as well
as far as the length of the valve that along with the camshaft endplay can be checked with dry assembly of the head on the bench
there is a certain range the valve adjuster eccentrics only work in and like flug is saying too much stickup may get you out if range

Hahaha thanks flugtechnik. If I could do it again I would definitely not choose a bike this rusty for my first project. Oh well.

The seat of the intake valves looked really shiny and unused. The seat of the exhaust valves didn't look as great, but there was no sight of pitting on either of the seats so I opted to just lightly lap the valves 3-4 times. Each time I used a mineral spirits leak test to crudely check the seating, and compared my results to my first leak test as a baseline.

I must say, even with my untrained eyes, the internals of this engine look pretty great. Compared to several other rebuild posts I've seen, all of my internal engine components do not seem worn down at all. Meaning, cam chain followers, anything with teeth, valve seats, pistons, etc. do not look worn down at all. Just kinda old. Given that the bike was a pile of rust when I bought it, this is a gift from the moto gods. My guess is that the original owner casually rode this bike and then stored it outside for many years.
 
Small Strides Today

Nothing huge today, mostly aesthetics. Realized I need to order the seals for the eccentric shafts and, while I'm at it, order the rest of the seals for the motor and forks.

Went through the goodies I ordered before vacation. Most were purchased through DCC:

Acewell tach/speed


Cam chain, engine oil seal kit, wheel bearings (front and rear)


From left to right--master cylinder rebuild kit, master cylinder seal, fork gaitors, fork dust covers, handlebars, headlight mounts, adjustable rearsets

I'd really like to get the silver sections on the handlebars the same brown color as my rims. Rearsets will be painted black, maybe the pegs painted brown.

Paint set up for today:



Rustoleum Primered the swingarm first, then mixed with VHT epoxy. Bad flaking results. Need to sand and re-do tomorrow :(

First set of spokes (rear) and bottom forks were painted with caliper paint






Went through and sorted out my pile of parts and bolts. The pile on the furthest right is all the deleted things off the bike!


Measured my old clutch springs. Not a very accurate micrometer (harbor freight), but it'll have to do for now.
Clymers Manual: 40.1 - 39.4mm range for free springs (not compressed)
Picture looks like I'm compressing the springs, but it's just for the sake of holding the camera with my right hand.

Old springs


New springs


Ordering all seals tonight. I'm eager to rebuilding the forks, but need to wait until seals come in. Tomorrow's To-Do List includes sand+paint swingarm, paint front spokes and all nipples, start installing bottom case components, and anything else that comes to mind.
 
Painted the frame with black caliper VHT paint. Planning on powder coating down the line after a few seasons, but unfortunately cant afford that at the moment.



Cleaned the piston heads. Almost ready to seat the new rings. I need to buy a new honing tool and de-glaze the cylinders first.
Comparison of old and cleaned. The black dots on the cleaned piston are from pitted rust, I believe.




Rebuilt the forks with new seals, touched up the chrome parts, put new dust cover and gaitor.
Ran into trouble with my 2nd fork; the damper rod is SEIZED.



Tried to do a few PB blaster soaks, and also fed oil through the bottom hole and let gravity work it's way down (opposite of pic). Neither method has worked. The rod will slide and compress a little, but then ends up getting stuck every time. Feels a little gritty(?) inside when I compress it by hand.
I'm in the market for another damper rod for 1 fork now.



Installed All-Balls tapered bearings.
Did not have my old bearings to measure and see if I needed spacer(s) or not with my set up, but after searching online most people seemed to use the thin spacer at the bottom. My old races were a #%@%! to take out. Much easier to put in the new ones back in, fortunately. I wish I had taken pictures of the steps, but bottom set up was pressed in with my hydraulic press for good seating.



Issues:
- I seem to only have a few threads for the top spanner lock nut to grab onto. I've researched and only found one other person with the same amount of threads as me.

- There is a bit of vertical play in the stem, but the steering from left to right is smooth. If I change out the bottom thin spacer to the thick spacer, will this alleviate the vertical play?


This bike has been tough at every part!
 
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