'78 Honda Twin Project

Discussion in 'Technical & Maintenance' started by TonisToo, Oct 5, 2017.

  1. TonisToo

    TonisToo Active Member

    I think that's my problem, the rocker should be loose I believe and I remember it being loose on the exhaust side and don't remember checking on the intake before I cracked the lock nuts. Will re-do this evening and compare. Thanks!
     
    Wayne likes this.
  2. HerrDeacon

    HerrDeacon Active Member

    The Honda 400 engines are a bit noisy but shouldn't be overly loud, just a bit ticky. With the valves the manual sort of leads you to believe that you do both cylinders at the same time but that's not the case, you do one at TDC compression stroke then then cycle the engine until the other one is at TDC compression. To ensure you are on the right stroke, rotate the engine and keep an eye on the valves, you'll see the intake open letting the air/fuel mixture in and then after it closes when the piston goes to TDC that is where you check the clearance (should also line up with the T mark on the rotor). I can't remember the firing interval of the 400 engine but just do the same thing for the other side.

    The balancer chain can also create a bit of noise if its out of adjustment too. Newer engines have a adjustment port on the left hand side but not sure if your model does or not, you may need to take the entire side cover off. Can you tell where the noise is mainly coming from? Head, back of engine or front lower of engine? This would help in figuring out which part is the noisy one.
     
  3. TonisToo

    TonisToo Active Member

    Perfect thanks, I'm pretty sure I need to re-check as I was not at TDC at the appropriate time. The manual is a bit vague on this. Great learning experience! the balancer chain is really easy to adjust on this bike.
     
  4. TonisToo

    TonisToo Active Member

    First instance where the Clymer Manual was a little clearer. Should have read it last night. This bike has a 360 degree crank with a counter balance shaft. Therefore both pistons moving in the same direction at the same time however one piston will be rising on the exhaust stroke and one will be rising on the compression stroke. This explains my problem. Thanks Wayne and HerrDeacon.
     
    Wayne likes this.
  5. Trash

    Trash Active Member

    I guess it’s better late than never to check the ol’ Service Manual! :rolleyes:
     
  6. TonisToo

    TonisToo Active Member

    In this case the service manual was more vague than the Clymer to my poor scrambled brain. I understand now what I did wrong based on a new understanding of the firing order. I re-did the work last night (much faster too) and of course one cylinder was perfect and the other too loose. Bike sounds normal now. Learning is fun! I won't quit my day job just yet :)
     
    RossKean likes this.
  7. HerrDeacon

    HerrDeacon Active Member

    Clymer and Haynes are aimed at the backyard mechanics like us so they explain the steps a bit better than the official service manuals that are more for the actual dealer mechanics. I try to get both versions if I can, never hurts to have more info. Always check the official manual for specs like clearances and torque since the Clymer manuals have been known to have errors sometimes. Even the official ones do too but less frequently.

    Agree on the learning, its the reason why I pick at these old bikes, very interesting and great bit of fun. They are so much nicer to work on compared to the newer bikes too.
     
  8. Trash

    Trash Active Member

    Your brain is fine.
    It is a real skill for a mechanic to be able to concisely describe a procedure.
    Mostly they fail miserably at communication, despite being excellent mechanics.
     
  9. TonisToo

    TonisToo Active Member

    The tiny light that flashes when the turn signals are on quit. Parts bike to the rescue again for an easy fix. A bit of high temp sealant provided a cheap and quick fix as an alternative to sourcing new exhaust packing. The bike is much quieter now. Idle was a bit high, fortunately you can adjust it at a stop light with one hand. Bike is working great and I burned a tank of gas in it over the long weekend with the gorgeous weather. I think this is the most riding I have done in Newfoundland in mesh gear. cb400111.jpg
     
  10. keith

    keith Active Member

    #jealous

    I need mesh gear!
     
  11. TonisToo

    TonisToo Active Member

    I have REV'IT brand and it fits really nice. I added the optional back protector to the jacket. I got the jacket while on a trip to the US and the pants came from Ralleye Motoplex in Moncton. I'm comfortable in it at 15 degrees and above. I got caught when temps dropped to 10 in the evening one time and I was froze.
     
    keith likes this.
  12. Trash

    Trash Active Member

    I have had an Olympia mesh riding suit for about five years now, and don’t know how I survived without it in the past.
    It is a bit inconvenient to have to stop and put on the rain gear before it rains, but on the other hand, if you get caught in a brief downpour, the suit also dries quickly. I still have a hard time getting used to the breeze on my legs when riding with shorts on under the suit in hot weather, but it sure feels good! :p
     
    keith likes this.
  13. TonisToo

    TonisToo Active Member

    SOLD today to a nice man from Iceland. Probably will become a café racer.
     
    keith, skibum69 and Trash like this.
  14. Trash

    Trash Active Member

    Of course he's a nice guy.
    He bought the Honda!
    You always meet the nicest folks on a Honda.
    Or so I've been told...
    Congratulations!!
     
    TonisToo likes this.

Share This Page