1. Husqvarna Motorcycles Made In Sweden - About 1988 and older

'73 400CR The journey begins....

Discussion in 'Vintage/Left Kickers' started by TexasMule, Jul 10, 2020.

  1. TexasMule Husqvarna
    B Class

    Husqvarna Motorcycle:
    1973 400CR
    Other Motorcycles:
    BMW R1200RT
    Been looking for an MK Husky for many years. Finally found one in pretty decent shape.

    [IMG]

    So now the journey begins. It appears to me to be a very low hour bike. I pulled the head and it looked unbelievably clean.

    [IMG]

    That's after wiping the oil off with a paper towel.

    I think it's the original piston. Standard bore is 81.50 and it's stamped 8142 ????? Not sure
    what the 52/110 means.

    [IMG]

    Here's the piston before I cleaned it up for the photo. I used to race Huskys and this
    is in better shape than after 3-4 races.

    [IMG]

    I have one last question for the evening. It appears someone may have performed a
    LeFevre frame modification on the bike.

    [IMG]

    Because the gas tank doesn't fit over the rear bolt hole.

    [IMG]

    It's been a few (45) years since I worked on Huskys, thought maybe some of the experts
    on this forum could help me out.

    Thanks,
    Bill
    Steve-F and markt2 like this.
  2. TexasMule Husqvarna
    B Class

    Husqvarna Motorcycle:
    1973 400CR
    Other Motorcycles:
    BMW R1200RT
    John does his modification BEHIND the rear tank bolt not in front like the goob did on my bike. :naughty:
    Picklito and Steve-F like this.
  3. Steve-F Husqvarna
    A Class

    Location:
    Vista,Ca.
    Husqvarna Motorcycle:
    1975 Husqvarna 360 CR GP
    Other Motorcycles:
    1965 Norton G15CS 750
    Yes, I have seen John's work and agree with TexasMule, John is only 10 miles from me;)
  4. TexasMule Husqvarna
    B Class

    Husqvarna Motorcycle:
    1973 400CR
    Other Motorcycles:
    BMW R1200RT
    I'm not sure if I ever put up photos of the finished project. She turned out pretty well. I'm pleased.

    [IMG]
    DeathFromAbove and Crashaholic like this.
  5. Crashaholic Husqvarna
    Pro Class

    Location:
    Antelope Valley, CA.
    Husqvarna Motorcycle:
    73 450WR 6spd motor in a 75 MK frame
    Very nice! Wouldn't mind having that in my garage, although it wouldn't be as clean. Curious if the frame mod improves turning ability (as stated on Johns site) enough to make it worth while. I'm not a motocross guy so I don't know how to turn anyways.
    DeathFromAbove likes this.
  6. TexasMule Husqvarna
    B Class

    Husqvarna Motorcycle:
    1973 400CR
    Other Motorcycles:
    BMW R1200RT
    As I said in a previous post. John does his frame modification BEHIND the rear tank mount, not in front.

    Someone else will have to chime in if the modification improves turning ability. I haven't raced/ridden this bike since I got it.
  7. Crashaholic Husqvarna
    Pro Class

    Location:
    Antelope Valley, CA.
    Husqvarna Motorcycle:
    73 450WR 6spd motor in a 75 MK frame
    Being curious about the frame mod I checked out LeFevres website and it looks like he doesn't cut the backbone, only the sub-frame where it meets the backbone. Then he makes two small bends in each of the two the sub-frame struts. Also looks like he makes a bend in the rear fender loop.

    By cutting the backbone it looks like a different approach was used on your bike. Its interesting the different ideas implemented back in those days.

    I remember seeing a motorcycle magazine article long ago of someone offering to turn an MJ or MK frame into a cantilever setup (i.e. lay down shocks).

    frame2b.jpg

    frame3b.jpg

    frame5b.jpg
  8. Picklito Husqvarna
    Pro Class

    Location:
    Washington
    Husqvarna Motorcycle:
    430, 430, 430, ,400, 175
    Other Motorcycles:
    KTM250xc, KTM500mx, KTM440exc
    John's mod is simple and very effective. He did it on my 73 400CR. He moves the forward seat tubing up and forward (yellow arrow), which creates a slight bend in the seat stay tube (blue circles).


    IMG_7062.jpg
  9. Picklito Husqvarna
    Pro Class

    Location:
    Washington
    Husqvarna Motorcycle:
    430, 430, 430, ,400, 175
    Other Motorcycles:
    KTM250xc, KTM500mx, KTM440exc
    It creates a much flatter seat profile and allows you to get forward more easily. It works.
    Yes, I know this is the wrong tank! This was the mock up.

    IMG_6998.jpg
  10. Crashaholic Husqvarna
    Pro Class

    Location:
    Antelope Valley, CA.
    Husqvarna Motorcycle:
    73 450WR 6spd motor in a 75 MK frame
    Wouldn't a flat seat, vs a forward slanted one, help with staying on the rear of the seat will less effort. From a grumpy old desert racers perspective, that would help reduce fatigue in a 100mile H&H.
  11. Picklito Husqvarna
    Pro Class

    Location:
    Washington
    Husqvarna Motorcycle:
    430, 430, 430, ,400, 175
    Other Motorcycles:
    KTM250xc, KTM500mx, KTM440exc
    Hey Crash, I get what you're saying. I feel it makes the seat tank transition much flatter. I actually sit right on the back of that tank in some corners. It was harder to do that before the mod.