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

Consider the YZ490 Connecting Rod

Discussion in 'Vintage/Left Kickers' started by 390Dave, Mar 29, 2013.

  1. 390Dave Husqvarna
    A Class

    Husqvarna Motorcycle:
    83 250XC
    Other Motorcycles:
    80 Maico 440 84 IT490 84 MXC 250
    While looking through some old part catalogs tonight,I stumbled upon the specs of the 1983-1990 Yamaha YZ490 connecting rod.The YZ/IT 465 and WR500's might use it also.Although it is 2mm longer{at 137mm} than most 1975-up air cooled 250/360/390/420/430 rods,it does have the same 25mm diameter X 64mm long {would need to be shortened}crankpin,and uses the same diameter 18mm wrist pin.22mm small end bore.Small end might be able to bore and bush to 135mm.Width at big and small end is reported as 20mm.Looks compact enough to rotate without contacting the cases.Wossner does make pistons from 83mm up to 86mm for 390/420,with 35mm{8249DA series} compression height,2mm shorter than stock,which is 37mm.With the supply of original Husky rods and Eurorods{not available} about to dry up,it might be something to consider.On most engines,you might be able to juggle cylinders,heads and gasket thickness to get the deck height and squish established,or a 1mm thick spacer plate.I have seen some factory stock 390's and 430's over the years with the piston more than 1.5mm down the bore at TDC!!Some further searching shows that guys are running this rod{modified to fit} in 490 Maicos,without incident.Tomorrow I will try to measure the big and small end width of a stock husky rod,to see how it compares.
  2. fran...k. Husqvarna
    AA Class

    Location:
    eastern ct
    Husqvarna Motorcycle:
    420ae 98wr125 2004wr250 others
    Other Motorcycles:
    electric freeride 1993 yam gts
    The 420 piston is the same as a 430 piston of that era, at least in my parts pile.

    I think it was Andy in another post that mentioned the pin should be just a bit larger on a crank rebuild. I contacted bley engineering who used to restore crankshafts of this kind particularly with the bmw roller crank community but he informed me due to age they are getting out of the crankshaft business. What they did was to make a pin to fit the crank cheeks, made a cage and fit up the proper sized rollers. I fail to recall what they do with the rod. At one time they had quite a list of what is now antique bikes they would do. A true Harley enthusiast will be able to tell you when they stopped using the fit the proper size roller technique. Surely someone has to do this kind of stuff for the guys restoring real antiques. Though Mr Bley suggested looking to europe on these ones.

    Chances are an auto rod would be in pretty good shape so long as the lower end didn't get flooded. You still need to have a pin and rollers made up. If there are still 25 or so old stock probably something to consider. There were a bunch of 500 standard shift and 420 auto cranks dumped on ebay probably around the time ferachi ceased to be the importer not sure how many folks on here got some of them.

    Fran
  3. 390Dave Husqvarna
    A Class

    Husqvarna Motorcycle:
    83 250XC
    Other Motorcycles:
    80 Maico 440 84 IT490 84 MXC 250
    Had a chance to measure a stock connecting rod today,assembled #2066 1979 250 WR:Big end @.625 or 15.875mm,Small end @.870 or 22.098mm,so the YZ490 rod can be used once modified to fit. The rod I measured is the original to this engine and is worn and rusty,even if .640 when new,we're still in the game.Best advice I could give is measure the crank for total width vs. the factory service manual,measure for existing rod side clearance before disassembly,measure old rod big end width,calculate your new big end width at .018 side clearance,take the rod to a local machine shop that has a surface grinder with a magnetic chuck,provide your needed measurement,and how much material to remove equally from each side.You can have the 64mm YZ pin cut down to 52 or 58.3mm while youre at it.As far as the top end,you can either use the spacers or mill the inside of the pin bosses.
  4. 1982 XC 430 Husqvarna
    AA Class

    Location:
    Seattle Wa
    All though the Yamaha Rod has been used in the Maico 490 there really isn't any reason as a reproduction of the Maico Rod is avalable.
  5. 390Dave Husqvarna
    A Class

    Husqvarna Motorcycle:
    83 250XC
    Other Motorcycles:
    80 Maico 440 84 IT490 84 MXC 250
    There is a repro Maico rod available now,years ago there wasn't.They also used Suzuki RM370/RM400 pistons when the OEM Mahle supply ran out.
  6. SA63 Husqvarna
    AA Class

    Location:
    Glasshouse Qld, Australia
    Husqvarna Motorcycle:
    84 510, 500 auto , 86 510
    maico rods are dime a dozen these days..
  7. 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 was doing some research on Hot rods website and came up with a few rods they make that have 135mm center to center dims. One is very close with 26mm for gudgeon pin and close on wrist pin size. The rod is for a Kawasaki street bike that was made from 1997 to 2011. It is an inline 4 cylinder four stroke. The picture shows similar construction (single piece forging). As long as the rod con be modded to fit the application, does the fact it is made for a 4 stroke keep it from consideration?
  8. 390Dave Husqvarna
    A Class

    Husqvarna Motorcycle:
    83 250XC
    Other Motorcycles:
    80 Maico 440 84 IT490 84 MXC 250
    Jim,without seeing the part,as long as its made from good material and has adequate cross section it would probably work.I would not want oil holes or a bronze bushing in the small end of a 2 stroke.Does it have slots in the big end to provide oil?Most nagasaki street bikes have pressurized oiling systems. ZRX1100? Falicon, Carillo and Crower also make connecting rods for similar applications.Crower made the rocker arms for the 510 air cooled Husqvarna 4 strokes
  9. hva-factory CH Sponsor

    Location:
    uk
    Husqvarna Motorcycle:
    Husqvarna 510TE , 300WR Etc...
    We have some NOS Genuine complete rod kits, but not too many!! Can I suggest that you buy one and use that. They last for 25 years if looked after which makes them cheap compared to risking everything using something else

    Andy.
  10. 2premo Husqvarna
    Pro Class

    Location:
    Northern NV
    Husqvarna Motorcycle:
    98 WR360, 1987 WR430, 1988 XC430
    Other Motorcycles:
    Sherco 300, 2002 KTM 380EXC

    Nagasaki, now that's funny stuff:thumbsup:
  11. jimspac Husqvarna
    Pro Class

    Location:
    Connecticut
    Husqvarna Motorcycle:
    82 250WR, 82 430WR, 84 250WR, 85 400
    Other Motorcycles:
    86 400WR, 82 Montesa Cota 349
    Hot Rods makes their connecting rods from forged 8620 and carburized to 58-60 R/c. Seeing that they have forging dies for the center to center, it may be worthwhile to have them make a run of 25 to Husqvarna specs. Geometrically they are in the ballpark without developing a forging die. Simply omit machining process for unwanted features.

    I just looked at the replacement 430 crank and the rod end in the 400 L/C. They both have oil holes in the small end and no oil slots in the big end.

    If I can get enough commitment here for rods, I will contact Hot Rods and ask them if they will modify one of their existing products to our needed specifications. I would like to submit for 25 pieces and I intend to purchase (2) for my own needs.
  12. 2premo Husqvarna
    Pro Class

    Location:
    Northern NV
    Husqvarna Motorcycle:
    98 WR360, 1987 WR430, 1988 XC430
    Other Motorcycles:
    Sherco 300, 2002 KTM 380EXC
    I am interested, find out how much, is it safe to assume the pins and bearings are available?
  13. jimspac Husqvarna
    Pro Class

    Location:
    Connecticut
    Husqvarna Motorcycle:
    82 250WR, 82 430WR, 84 250WR, 85 400
    Other Motorcycles:
    86 400WR, 82 Montesa Cota 349
    26mm pins and bearings were packaged withe the "Nagasaki" rods. My intent is to have rod kits produced. The big end pin and wrist pin diameters seem to be very common in search results. I will ask for a price when I know that 25 can be purchased. I am not doing this for a profit, I want to see options exist after HVA sells off the 25 NOS rod kits that they have.
  14. 2premo Husqvarna
    Pro Class

    Location:
    Northern NV
    Husqvarna Motorcycle:
    98 WR360, 1987 WR430, 1988 XC430
    Other Motorcycles:
    Sherco 300, 2002 KTM 380EXC
    my local dealer has a rod kit for an auto seems the difference is the big end pin is shorter due to engine width accommodated by thinner crank halves
    where might I find a pin and still interested in one rod
  15. jimspac Husqvarna
    Pro Class

    Location:
    Connecticut
    Husqvarna Motorcycle:
    82 250WR, 82 430WR, 84 250WR, 85 400
    Other Motorcycles:
    86 400WR, 82 Montesa Cota 349
    My plan is for a rod kit that would include that
  16. 390Dave Husqvarna
    A Class

    Husqvarna Motorcycle:
    83 250XC
    Other Motorcycles:
    80 Maico 440 84 IT490 84 MXC 250
    2premo,Husqvarna-Parts sell just the crankpin and silver plated big end bearing,available in several lengths.You can shorten the pin in the rod kit too.
  17. 390Dave Husqvarna
    A Class

    Husqvarna Motorcycle:
    83 250XC
    Other Motorcycles:
    80 Maico 440 84 IT490 84 MXC 250
    How about complete,reproduction air cooled 510 engines?Ill take mine optioned with electric start and a twin plug head,Cam driven Joe Hunt magneto/with 130 watt alternator off the clutch ring gear,and one of UpTite Georges countershaft oil pumps.Oil filter and oil cooler. S&S? Edelbrock? TPengineering? no billet though,cast aluminum.
  18. jimspac Husqvarna
    Pro Class

    Location:
    Connecticut
    Husqvarna Motorcycle:
    82 250WR, 82 430WR, 84 250WR, 85 400
    Other Motorcycles:
    86 400WR, 82 Montesa Cota 349
    You can try to find someone to build it for you if you really want one. I am focusing on finding a viable alternative for a problem that two separate Husky forums are constantly running up against. In case you have not paid attention to the last few posts, I am no longer talking about modifying "Nagasaki" rods but building something Husqvarna specific from a viable raw forging they already have the forging die for. If you do not want to be involved that is fine by me. You are welcome to pay whatever it costs to get what you need. Right now choices for this model common rod we are talking about costs $325 here and $433 from UK at least according to yesterday's exchange rate
  19. 390Dave Husqvarna
    A Class

    Husqvarna Motorcycle:
    83 250XC
    Other Motorcycles:
    80 Maico 440 84 IT490 84 MXC 250
    Easy now Jim,in case YOU havent been paying attention,I AM the person that started this thread to begin with,4 months ago.Anyone with access to a machine shop with a surface grinder can make the Yamaha part work.I have no commercial interest here,I share what I know/learn to benefit everyone.If you care to look back over a few previous posts,I have suggested and recommended other Nagasaki parts that interchange or could be modified to work in place of Husky OEM,my brand of humor.
  20. 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 been paying attention but what you seem to not realize that not everyone has access to a machine shop. I have worked in them for over 30 years and have even had my own shop for 8 years. I kick myself every time I lose a job that I let my wife push me into selling it all off just because I had not used them for a few years. I had enough equipment to build most anything the forum needs. I am trying to get the forum a chance to buy sometime they can just use, without buying something that they have to pay a machine shop to do something that the shop if profitable does not take in such jobs.


    Just so that everyone is clear, I have no commercial interest involved in this idea. If I did I would just supply some company with an RFQ and full dimension , get a price, add a markup, and put them on eBay. I want to try to get it to the point the rod kits can be ordered like any other rod kit they make. That seems to be fairly and competitively priced for an American product