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

Crank end advice 390

Discussion in 'Vintage/Left Kickers' started by dartyppyt, Dec 16, 2014.

  1. dartyppyt Husqvarna
    Pro Class

    Location:
    Illinois
    Husqvarna Motorcycle:
    17 TE 150, 82CR 500
    Other Motorcycles:
    82 125,250,430&500 79 390 83 250
    Guys, need lil advice?

    On my 79 390 engine. The crank has the larger end for the flywheel. Also, the stator plate is further out from all my 82+ ignitions I have. Even got a fairly new SEM ignition I could use. There also was an adapter plate? If I could even find one?

    The end of the crank is pitted where seal rests. So I know it will not be an air tight seal.

    Do I just press out the crank end and get cut, re chromed then grind and polish back to size? That's $110.
    Been watching for long time and have not seen a good 390 crank end available.

    But that means have to go Mzb $500 ignition. So prob looking at $700 when said and done for!

    Or can I just get the newer crank end that is 14 mm and put on the newer Electrelex ignition, from 82 +. Then make an adapter plate? This will give me the inner rotor ignition, like a CR. I am not worried about flywheel effect unless it throws, overall crank balance off with cheek crank weights?Guess don't have to worry about lining up key ways anyways? So going this route? Could prob pull off $350 bux, plus have newer ignition. Prob start better as well?
  2. 84scrambler Husqvarna
    Pro Class

    Location:
    mid Florida
    Husqvarna Motorcycle:
    87 xc 250, 85 wrx 250, 79 wr 250
    Sounds like a good one for huskydoggg ? Hey Darty do you have a source for viton crank seals ? I want the good ones because I have had some others fail due to not doing the work my self or parts failure ???? I will know soon when I split cases but I would like the new seals ready to go in as I get her broke down.
  3. dartyppyt Husqvarna
    Pro Class

    Location:
    Illinois
    Husqvarna Motorcycle:
    17 TE 150, 82CR 500
    Other Motorcycles:
    82 125,250,430&500 79 390 83 250
    I use this metric seal place a lot. They been around for years.Plus I know a lot of other guys/dealers go here for good seals.

    Also, those bronze wear strips for shock stuff, they have as well. These guys have tracked down some hard to find stuff for me over years.

    https://www.metricsealsinc.com/store/default.aspx

    There is also another good metric seal place in Greenfield Indiana, but can't remember name?
  4. dartyppyt Husqvarna
    Pro Class

    Location:
    Illinois
    Husqvarna Motorcycle:
    17 TE 150, 82CR 500
    Other Motorcycles:
    82 125,250,430&500 79 390 83 250
    Here it is:

    MSP seals:

    http://www.mspseals.com/index.aspx

    These guys are good when you buy, ones and twos. Lot of other places won't sell unless you by 100.

    My son had a Husky 06 Wr 125, that we kept blowing the crank case side seal.
    It had a little wear lip spot on crank where seal was. I talked to guy at Metric seals and he got me a real good seal. It was like $40 or $50 bux but we never blew it after that. Was better than splitting cases and getting a new crank end. The ignition side one are not bad to replace but always put a good one in on the other side, so you don't have to split the cases. I had a couple of those blue double lip ones I found on a dealer shelf, so used them up but I still got to get some good ones for few engines yet to assemble.
  5. SK Marls Husqvarna
    C Class

    Husqvarna Motorcycle:
    CR400, CR430
    Other Motorcycles:
    Only Huskys
    Dart: A new crank stub seems a lot easier and less expensive. Hall's, Huskydoggg, or Forrest Stahl will have one.
  6. jimspac Husqvarna
    Pro Class

    Location:
    Connecticut
    Husqvarna Motorcycle:
    82 250WR, 82 430WR, 84 250WR, 85 400
    Other Motorcycles:
    86 400WR, 82 Montesa Cota 349
    I have stub ends from a 1982 250 crank and a 1982 430 crank. I am toying with the idea of putting a 1982 stub end on the right side of the 390 crank so I can use an SEM on that
  7. dartyppyt Husqvarna
    Pro Class

    Location:
    Illinois
    Husqvarna Motorcycle:
    17 TE 150, 82CR 500
    Other Motorcycles:
    82 125,250,430&500 79 390 83 250
    Yeah, I with you on that too! Just need to see what I need adapter wise to go from SEM stator plate to the 390 mounts?

    Or guess make one?
  8. Kartwheel68 Husqvarna
    Pro Class

    Location:
    Newnan, Georgia
    Husqvarna Motorcycle:
    82 125XC, 250XC, 430XC, 430WR, 250CR
    Other Motorcycles:
    83 175WR , 76 250WR, 74 250 Mag
    The '82 stator plate wont work?
  9. dartyppyt Husqvarna
    Pro Class

    Location:
    Illinois
    Husqvarna Motorcycle:
    17 TE 150, 82CR 500
    Other Motorcycles:
    82 125,250,430&500 79 390 83 250
    No, it is way off? Meaning too short radius with ear tabs.
  10. grouty Auto Lover ...

    Location:
    South West UK
    Husqvarna Motorcycle:
    78 390WR, 78 390 AMX, 500 Humph
    Other Motorcycles:
    works 73 CCM 520, another 73 CCM520
    I have just replaced both crank stubs on the Auto. The ignition side is a 14mm unit (medium taper ?). These are available new. I have dry fitted my new Electrex World unit and all seems good. The new ignition came with it's own backplate that just attaches with the supplied M5 bolts. A visual check of the timing looks good. I have yet to fish out the dial gauge and finish it properly. Would this suit your needs ?
  11. dartyppyt Husqvarna
    Pro Class

    Location:
    Illinois
    Husqvarna Motorcycle:
    17 TE 150, 82CR 500
    Other Motorcycles:
    82 125,250,430&500 79 390 83 250
    What Electrelex ignition are you using via part number?

    I assume it has a wider radius for the 390 case versus mounting to like a 82 Cr 250 case?

    Is it internal flywheel or external?
  12. grouty Auto Lover ...

    Location:
    South West UK
    Husqvarna Motorcycle:
    78 390WR, 78 390 AMX, 500 Humph
    Other Motorcycles:
    works 73 CCM 520, another 73 CCM520
    Part number is STK185L (the L bit is for the lighting coils)
    What would you like me to measure ? The diameter of the mounting plate ?
    It is external flywheel. If I get a chance tonight I will pop down to the workshop and take some pictures and any measurements you need.
  13. dartyppyt Husqvarna
    Pro Class

    Location:
    Illinois
    Husqvarna Motorcycle:
    17 TE 150, 82CR 500
    Other Motorcycles:
    82 125,250,430&500 79 390 83 250
    Sure,

    That would be a big help!

    Ok so you used a 14mm crank end? And you pressed it in old 390 crank cheek and assuming you pressed it back in with key way ?

    Then you used STK185L kit, so what is the radius width of your stator plate? Some old stuff references 130mm? Guess we will find out.

    Yes pics will help and Electrex fly wheel doesn't have a key way any ways correct?

    Thought I read once that changing crank ends, some key way slots were off. Guess it doesn't matter anyway with no need for woodruff key.

    Thanx million!

    I will measure my case tonight.
  14. grouty Auto Lover ...

    Location:
    South West UK
    Husqvarna Motorcycle:
    78 390WR, 78 390 AMX, 500 Humph
    Other Motorcycles:
    works 73 CCM 520, another 73 CCM520
    The 14mm crank end was an original fitment on the Auto. I just replaced it as mine was the same as yours with wear and pitting. It had the keyway for the crank too. With the crank keyway at 6 o'clock the ignition keyway is at 11 o'clock. The 130mm refers to the diameter of the plate. I will measure that in a mo. The Electrex flywheel that I have here has two keyways next to each other. As far as the ignition keyways being off, that was a cock-up in the parts manual ! I did a post on this some while ago. The keyway for my 78 390 needs to be as per the above.
    I will brave the rain and cold wind now and go to the man-cave ;)
    dartyppyt likes this.
  15. grouty Auto Lover ...

    Location:
    South West UK
    Husqvarna Motorcycle:
    78 390WR, 78 390 AMX, 500 Humph
    Other Motorcycles:
    works 73 CCM 520, another 73 CCM520
    Right .... this is the kit as supplied. The only part not pictured below is the stator. You can see that in the later pictures.
    The two keyways are clearly visible. This will give ignition and a healthy 12 volt source for lighting ( I guess about 75 watts or so). Voltage regulator, plug cap, coil, coil to frame bracket, flywheel nut and kill button included. These are the kits that Andy at HVA Factory supplies. I am not sure what you get with ones direct from Electrex. I think there is also an "ignition only" kit available if you don't want lights.

    [IMG]


    The flywheel measures 103.12mm in diameter.
    [IMG]



    The stator plate measures 110mm diameter

    [IMG]


    Crank position at about TDC
    [IMG]


    Stator plate in position. It still needs to go a small amount anti-clockwise. There is still a small amount of adjustment when this is done. I will let you know when it is finally fitted and timed.

    [IMG]


    [IMG]



    Flywheel fitted roughly in line with the top keyway (right hand one). This lines the mark on the flywheel with the mark on the stator plate.
    You can just see the original mark on the engine casing beside the cover fixing bolt. This is now redundant. The flywheel protrudes about 28mm from the casing mating surface.
    [IMG]
    oldbikedude likes this.
  16. dartyppyt Husqvarna
    Pro Class

    Location:
    Illinois
    Husqvarna Motorcycle:
    17 TE 150, 82CR 500
    Other Motorcycles:
    82 125,250,430&500 79 390 83 250
    Ok I am 110mm for stator. Looks like the bolts line up as well on stator plate.

    Thank you very much
  17. jimspac Husqvarna
    Pro Class

    Location:
    Connecticut
    Husqvarna Motorcycle:
    82 250WR, 82 430WR, 84 250WR, 85 400
    Other Motorcycles:
    86 400WR, 82 Montesa Cota 349
    The hole spread on the 390 case is 180° rotated compared to 82> cases. I will be designing an adapter plate for SEM to 390 case conversion as the mounting holes are 180° apart and the base needs be larger diameter to mount in the 390 case. The stub end needs to replaced with the small taper from the 82 engines as well
    dartyppyt likes this.
  18. Bigbill Husqvarna
    Pro Class

    Husqvarna Motorcycle:
    '83 250wr
    Other Motorcycles:
    0 right now
    How much does the new flywheel differ in weight from the larger 390 flywheel?

    Meaning the 390 is a torque monster/beast with the heavier flywheel. Anything less in weight the 390 will turn into Godzilla. Be aware on your first earth turning ride.

    Sorry but my 390 was a sweet ride. All the husky riders who were also dealers loved the 390 engine. A twist of the throttle in sixth gear and she would wheelie. I lost 60lbs riding the '79 390cr 3 to 5 times a week. I did three passes on the easy trails and the 390 kicked my butt. Score bike 9 human 0. The 390 in that little frame destroyed newer 250's in the hill climbs. I sold one 390 to a local kid he kicked everyone's butt the husky had a neighborhood cult following.
  19. jimspac Husqvarna
    Pro Class

    Location:
    Connecticut
    Husqvarna Motorcycle:
    82 250WR, 82 430WR, 84 250WR, 85 400
    Other Motorcycles:
    86 400WR, 82 Montesa Cota 349
    I have not held the 2 flywheels simultaneously in each hand but I would have to say there is negligible difference between the Motoplat and SEM external flywheels in terms of weight. I got the Motoplat mini 6 with the 390WR engine I got. Since that will be in a personal rider for me, I will attempt an SEM conversion for it
  20. Bigbill Husqvarna
    Pro Class

    Husqvarna Motorcycle:
    '83 250wr
    Other Motorcycles:
    0 right now
    I have the 430cr with the internal motoplat rotor ignition. But I have the external motoplat flywheel ignition just incase having no weighted flywheel is too much in the woods. On a track it's different.