What I Learned it takes to bring an old Honda CB450 DOHC back to life
Results 1 to 10 of 10
Like Tree6Likes
  • 6 Post By JamesPal

Thread: What I Learned it takes to bring an old Honda CB450 DOHC back to life

  1. #1
    Senior Member JamesPal's Avatar
    Join Date
    Sep 2009
    Location
    Bellevue, Washington
    Posts
    3,328

    What I Learned it takes to bring an old Honda CB450 DOHC back to life

    This posting is long. It is what I did to my CB450 K5. Going in all I knew was I wanted a 450 DOHC and after 44 years working in aerospace I had a lot of mechanical experience. I had never restored a motorcycle before. The surprise came when I discovered how mental the process is. I hope this posting can serve as a guide for those who are considering brining an old Honda back to life.

    This is what the bike looked like on the day I brought it home back in September '09:

    What I Learned it takes to bring an old Honda CB450 DOHC back to life-img_2016_small_40.jpg

    After sitting in the back of the garage for 5 years and then starting work in March of 2014, it went on the first ride May 2, 2016:

    What I Learned it takes to bring an old Honda CB450 DOHC back to life-img_1548.jpg

    Brakes (Safety Item):
    Front replace the hoses, disassemble and clean master cylinder and the caliper.
    Replace the brake shoes or pads unless you know they are new. The lining will disbond from the frame.

    Cables (Safety Item):
    Ensure Clutch, Throttle and Front Brake cables are free of movement and are properly lubricated.

    Tires (Safety item);
    Replace if they are 5-7 years past the manufacturing date.

    What I Learned it takes to bring an old Honda CB450 DOHC back to life-img_2859.jpg

    Wheels (Safety Item):
    Remove the wheel bearings, clean inspect and regrease or replace with modern equivalents.

    What I Learned it takes to bring an old Honda CB450 DOHC back to life-img_2851.jpg What I Learned it takes to bring an old Honda CB450 DOHC back to life-img_2852.jpg

    Suspension:
    Remove and disassemble the front shock struts, check the stanchions for pitting and straightness. Install new seals.
    Remove the fork bridge, clean and regrease the bearings or install a All Balls tapered bearing kit.
    Remove the Swing arm, clean, inspect and regrease the swing arm pivot. Replace the bushings and seals.
    Verify the rear shocks have good dampening or update with modern shocks.

    What I Learned it takes to bring an old Honda CB450 DOHC back to life-img_2865.jpg What I Learned it takes to bring an old Honda CB450 DOHC back to life-img_2870.jpg What I Learned it takes to bring an old Honda CB450 DOHC back to life-img_2857.jpg What I Learned it takes to bring an old Honda CB450 DOHC back to life-img_2858.jpg

    Frame:
    Remove the center stand and rear brake lever. Clean, inspect the parts and regrease.
    Clean, inspect, remove corrosion and refinish any bare metal.

    What I Learned it takes to bring an old Honda CB450 DOHC back to life-img_2836.jpg What I Learned it takes to bring an old Honda CB450 DOHC back to life-img_2842.jpg What I Learned it takes to bring an old Honda CB450 DOHC back to life-img_2871.jpg

    Fuel Tank:
    Ensure the interior has absolutely no rust is in it. If there is any rust, install a tank liner. There are good products available. The liner will allow the tank to be drained during the winter with out worry of new corrosion. The engine depends on a clean uninterrupted supply of fresh fuel.
    Remove the petcock, clean, inspect replace the seals and strainer.

    Electrical:
    No shorts in electrical system. All fuses in good working order. Inspect every wire in each circuit. Make sure the wire is free from any damage, runs to the correct electrical appliance and all previous repairs are in good shape. Ensure every light bulb is the correct wattage and cross reference to the Honda specified bulb.
    Verify function of brake light switches.
    Charging system in good condition and charging according to factory specs. Replace to regulator and rectifier with modern equivalents.
    Battery new or tested good.

    Ignition System:
    Replace the coils and wires. Install an electronic ignition or new points and condenser. Oil and service the points and advance mechanism. Set gap and dynamic time the engine, left and right cylinder. Ensure the advance mechanism will reach the full advance. Install new plugs.

    Carburetors:
    Disassemble, clean, verify all passages are clear and fuel or air will pass. Clean each jet by inserting a wire through the fuel flow path, flush with aerosol carb cleaner. Ensure the needle is not worn and replace the main jet. The needle must float (move) in the slide. Replace the felt seals on the throttle shaft. Ensure the slides move freely and the vacuum pistons or boots are free from leaks, tears and are supple. Install new isolators. Bench sync the throttle valves and set the float height.

    Engine:
    Remove from the frame and disassemble. In accordance with the Factory Service Manual do the following.
    Head: Inspect the cam shaft, followers, valves.
    Inspect the cam chain, rollers and tensioner for wear.
    Cylinder Block: Check the cylinder for roundness and taper. If within spec use a glaze breaker to roughen up the cylinder walls. If they are out of spec have a machine shop machine hone or rebore. Pistons: verify the ring to grove fit is correct. Worn pistons will allow ring flutter and reduce compression at high RPM.
    Install new rings and pistons as required.
    Crankshaft: Verify the rod small ends are within spec.
    Check the crank bearings.
    Verify the oil passageways are clear including passageways through the crank.
    Left Side Cover: Remove the rear side cover and disassemble the sprocket, clutch mechanism and remove the neutral switch (if equipped).
    Remove forward cover, clean and inspect the stator and wiring.
    Right side cover: remove the clutch, oil pump, shifter linkage and shift detent. Make sure the detent roller and the selector are not worn.
    Crank Case: split the upper and lower halves. Clean any sludge from the lower section. Inspect the shift forks for straightness and wear on the fork faces.
    Inspect all gears, dogs and splines for wear and chips.
    Clutch: inspect the plates for wear and flatness. Check the springs for height and straightness.
    Inspect the clutch basket inner and outer for smoothness where they contact the disks.
    Soak the plates in clean motor oil before reassembly.
    Assemble: Reassemble in the reverse order making sure all components are clean and free of debris.
    Use generous amounts of quality assembly lube.
    Clean all gasket and seal mating surfaces and ensure they are flat and scratch free. Use RTV Silicone seal similar to Honda Bond on the seal edge between the upper and lower crankcase halves. Carefully apply the seal on a thin and even line that will not squeeze out. The squeeze out will break off inside the engine and clog the lubrication system.
    Use anti seize compound on all threaded parts.
    Install new seals and quality gaskets. Do not use gasket sealer.
    Set the piston ring gaps at 120 degree intervals.
    Set the cam timing and use a staked master link.
    Gently turn the engine over by hand. Stop if any resistance or binding is felt.

    Final Assembly:
    Install suspension front and rear. Ensure all parts including the upper fork bridge D shaped washers are installed. Service the front shocks to the correct type and quantity of fluid.
    Apply adequate grease is applied to all moving surfaces. Check the range of free movement.
    Check the tire manufacturing date to ensure the tires are no more than five years old.
    Install the tires and wheels.
    Install handlebars and battery tray.
    Install brake lever and pedal. Run front brake cable or fill and bleed the front brake.
    Adjust brakes.
    Install the engine into the frame. Ensure the ground between the frame, engine and negative battery cable are clean and free of paint or powder coating. Assemble this joint with wet primer.
    Fill the engine with the correct quantity and grade of oil. Be sure to use Chevron Delo 400, Shell Rotella or a oil specifically designed for motorcycles with wet clutches.
    Adjust clutch.
    Install fenders, speedometer — tachometer.
    Install wiring, rectifier, regulator lights (less headlight) and coils.
    Hook up wiring and check continuity.
    Install the carbs airfliters, exhaust and foot pegs.
    Connect spark plugs and static time the engine.
    Install battery and check each circuit for function.
    Install seat.
    Install gas tank, hook up fuel lines and partially fill with fuel.

    First Start up:
    Turn the fuel tap on, press the start button and if you did everything listed above correctly, it will start.
    Hold the engine at a lower RPM.
    Listen for any abnormal sounds.
    If the engine races shut it down and determine the cause.
    Allow the to come up to operating temperature. If the engine was painted with engine paint, the paint will cure.
    Check for oil leaks.
    Repeat the heating cycle two or three times. Do not allow it to get hot.
    Stabilize the idle as much as possible and dynamically set the timing for both pistons.

    First ride:
    Check tire air pressure.
    Check Brake operation front and rear.
    Start engine and away you go.
    Go for a short ride and bring the engine up to operating temperature.
    Return to base and check the bike for function and leaks.
    Do not exceed 2/3 throttle for the first 600 miles.

    What I Learned it takes to bring an old Honda CB450 DOHC back to life-img_0818.jpg What I Learned it takes to bring an old Honda CB450 DOHC back to life-img_0821.jpg
    Last edited by JamesPal; 06-11-2016 at 01:53 AM. Reason: Add Pictures
    Evenw, Dave240, 76TWIN and 3 others like this.
    Jim Palmer
    '85 GL1200I (Garage Find)
    '81 GL1100 STD (Project)
    CB450 K5 Done
    https://www.hondatwins.net/forums/1-...s-cb450k5.html
    What I learned from Restoring a CB450 K5
    Watch Mike and Jim Take on Mt Erie Washington State
    "If everything seems under control you are not going fast enough" Mario Andretti...

  2. #2
    Member jammer415's Avatar
    Join Date
    Jun 2014
    Posts
    39
    This is an AMAZING post... THANK YOU for posting this. Super helpful.

    And wow, a lot of work you did to the bike!

  3. #3
    Senior Member Rob Axel's Avatar
    Join Date
    May 2017
    Location
    Savannah Ga.
    Posts
    1,140
    Damn dude.. you spent more time on that post than I do on my bike!!

  4. Remove Advertisements
    HondaTwins.net
    Advertisements
     

  5. #4
    Senior Member Rscottp's Avatar
    Join Date
    Jun 2018
    Location
    Martha's Vineyard Ma
    Posts
    569
    Great job but aside from brakes cables and tires(safety stuff) l would consider what you did a restoration and way more than what is required to get back on the road. Just my two cents.
    1981 Honda CX500D
    1974 Honda CB450
    1986 Yamaha Radian 600

    Martha's Vineyard Ma

  6. #5
    Junior Member Bluesguitar's Avatar
    Join Date
    Nov 2017
    Posts
    24
    Did you switch out the handlebars and if so what is the new bar? Are your happy with the riding position? Any lessons learned with the install?

  7. #6
    Senior Member Lefty's Avatar
    Join Date
    Sep 2015
    Location
    Wisconsin
    Posts
    2,735
    Haven't heard from jamespal in awhile, hope alls good. I know he used the popular cb400 bars and really liked them.

  8. #7
    Junior Member Bluesguitar's Avatar
    Join Date
    Nov 2017
    Posts
    24
    Thanks Lefty
    so am I looking for the Honda CB400f bar or aftermarket if I want to use it on my 71 CB450?
    I’m assuming all the cable routing would be external?

  9. #8
    Senior Member ancientdad's Avatar
    Join Date
    Nov 2016
    Location
    Nature Coast FL
    Posts
    7,224
    Here are the 400F replicas I have from 4into1.com

    https://4into1.com/honda-cb400f-repl...000-1975-1976/
    Tom

    Ride along at the drag strip - https://www.youtube.com/watch?v=20jFPazXlvU



    running points... because I'm too old for mysteries that begin with pushing

  10. #9
    Member Busby's Avatar
    Join Date
    Aug 2013
    Location
    Mallorca
    Posts
    30
    What I Learned it takes to bring an old Honda CB450 DOHC back to life-1406382351095_slide-500x375.jpgHi James, Thanks for the info, thats been most helpful. I've found another CB450s in better condition with just 29k kilometres on the clock! Its been stood a while so the obvious things will need to be attended to before I can get it back on the road! photo attached! Once again thanks for the advice. regards Busby ps the 450s is an SOHC engine so maybe I'm in the wrong section?
    Last edited by Busby; 01-17-2019 at 10:03 PM. Reason: Engine for CB450s is SOHC not DOHC!

  11. #10
    Senior Member ancientdad's Avatar
    Join Date
    Nov 2016
    Location
    Nature Coast FL
    Posts
    7,224
    Quote Originally Posted by Busby View Post
    ps the 450s is an SOHC engine so maybe I'm in the wrong section?
    Bike looks nice... you are in the wrong section, but a moderator can move it for you - no worries
    Tom

    Ride along at the drag strip - https://www.youtube.com/watch?v=20jFPazXlvU



    running points... because I'm too old for mysteries that begin with pushing

Sponsored Links

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Search tags for this page

how to bring a honda shell back to life

Click on a term to search our site for related topics.