Building a 1981 Yamaha YZ465 Factory Replica...

Discussion in '2 smokers' started by FJ_Kevin, Mar 11, 2012.

  1. fastdadio

    fastdadio Still gettin faster

    Joined:
    Sep 18, 2009
    Oddometer:
    3,119
    Location:
    Pinckney Mi.
    I hate reading posts like this. Now would someone try to convince me that some men in this world don't need killin?
  2. FJ_Kevin

    FJ_Kevin Been here awhile

    Joined:
    Dec 28, 2010
    Oddometer:
    487
    Location:
    Maryland ==> originally from Long Island
    Well boys, I received some great news today at lunchtime!

    My two stolen YZ465's were found in the back of an apartment complex about 2 miles from where they were taken :clap.

    Police called just as I was sharing the story with guys at work. They were discovered in a ravine by an apartment maintenance man (yes, he will be rewarded!). He called the police who in turn called me.

    It looks to me like the knuckleheads never got them started. These 465's can take some kicking if you dont know the drill .
    My guess is they eventually got frustrated and so then sent them for a ghost ride down the ravine. Obviously they had no idea they were in possession of the now famous AVDrider YZ465 Factory Replica:evil!

    Fortunately, they are not too badly damaged. Mostly broken levers, bent fenders and side panels.

    One of the rear tires was knocked partially off the rim and that make it difficult to roll. We had a heck of a time getting them out and I re-injured my back in doing it. I was very fortunate to have three Baltimore County Police Officers who went beyond the call in assisting me in recovering them from the ravine. They got down there with me, in the pricker bushes and slick muddy slopes. They did a great deal of hard work in getting them out. I cant say enough about them and will surely
    be writing a letter of appreciation.

    Now that I have them back I have recorded the frame and motor numbers. Something I had not gotten around to doing. I also replaced the front door to the garage yesterday. The new door does not have a window.

    Several folks suggested I lock them up even when stored indoors and I will be doing that. You can bet I am working to tighten the overall security around here!

    The thieves themselves have not yet been identified :puke1 although police did lift prints off the garage door :lol3. After surveying the situation, one officer said these guys were not very bright, and that if not for this offense, they would eventually be caught for something :wink:.

    Here is a photo of the two bikes in the ravine. Trust me, the slope is much steeper than it looks!

    [​IMG]


    As you can imagine, I am really happy to have recovered these these. Especially the one that has been the focus here as I have so much time in it.

    Looks like the YZ Factory Racer thread continues!

    Kevin
    ozadvntr likes this.
  3. Shocktower

    Shocktower Long timer

    Joined:
    Jul 27, 2009
    Oddometer:
    9,535
    Location:
    Oregon City Orygun
    That is so great, I wish the same about my guns :cry, I found out I am missing 4 :eek1
  4. fastdadio

    fastdadio Still gettin faster

    Joined:
    Sep 18, 2009
    Oddometer:
    3,119
    Location:
    Pinckney Mi.
    Yea!!! This post really affected me. I have thought about it several times through the day. :freaky :clap Having restored a few myself, I could feel your pain. I'm sorry to hear of the damage that resulted, but it could have been worse. Gotta like a happy ending.
  5. ADK

    ADK master of the casual pace

    Joined:
    Dec 5, 2005
    Oddometer:
    8,253
    Wow, you got lucky! I didn't think you would ever see them again.
  6. wfopete

    wfopete Suffer Fools; Gladly!

    Joined:
    Aug 19, 2004
    Oddometer:
    626
    Location:
    Somewhere North of Dover, AR
    Gee Kevin, why didn't you just fire 'em up and ride them out! :D
  7. anotherguy

    anotherguy unsympathetic

    Joined:
    Jun 18, 2009
    Oddometer:
    9,077
    Location:
    the hills
    Good news.
  8. FJ_Kevin

    FJ_Kevin Been here awhile

    Joined:
    Dec 28, 2010
    Oddometer:
    487
    Location:
    Maryland ==> originally from Long Island
    Alright, things have finally settled down after recovering my two YZ465 :norton so I am now ready to refocus and continue on documenting the rebuild process started many months ago.

    Recall from earlier posts that the transmission has been reassembled and I had decided to assemble the rest of the motor using,

    - 5-speed yz465 gear set
    - 1985 YZ490 engine cases with offset clutch actuating arm bore
    - The YZ465 clutch basket with helical cut gear
    - The corresponding helical primary gear for the crank
    - YZ465 crank and cylinder

    Remember that using the late model engine cases requires I use the YZ490 clutch pressure plate too. This plate has a longer adjuster bolt that helpd make up for the offset in the clutch arm bore. Unfortunately you cannot simply swap the adjuster bolt into the yz465 pleasure plate as there is a difference in the casting that prevents this.

    I would have used the improved YZ490 straight cut basket as discussed previously but I did not have an extra straight cut primary gear at the time of assembly (although I do have one now).

    Here is one last photo of case comparisons that I did not post yet.

    I think the point of this one was to further show the difference in case venting between the early yz465 cases and later 490 cases. It also shows compares the casting numbers I found across various serial numbers.

    One final point is the difference in the early and later style clutch (pinion) shaft bearing. The early bearing is unsealed. For some reason they switched over the an internally lubricated sealed bearing. Perhaps this was to keep gear teeth shavings out of the bearing? I noticed Yamaha also moved to a sealed bearing behind the counter shaft sprocket as well.
    [​IMG]



    [​IMG]
  9. FJ_Kevin

    FJ_Kevin Been here awhile

    Joined:
    Dec 28, 2010
    Oddometer:
    487
    Location:
    Maryland ==> originally from Long Island
    I was fortunate to have several good crankshafts around from which to choose in my rebuild. Of course I had some bad ones too!

    One thing I was curious about at this point where the differences, if any, between the YZ465, IT465, IT490 and YZ490 crankshaft assemblies.

    This is what I found from the parts books.

    First, the exploded view of the YZ465 crankshaft assembly,

    [​IMG]


    Cross referencing the part numbers shows the crank to be interchangeable across all YZ465's and YZ490's.
    The rod assembly is interchangeable for all of the YZ's and IT's.

    [​IMG]
    There is a difference, however, in the crank flywheels between the YZ's and IT's. The YZ cranks have lightening hole in the flywheels that allow them to spin up more quickly. The IT cranks are solid making the IT465/490 more tractable and less likely to stall in a slow corner.

    Here some photos of the IT490 crank.

    [​IMG]

    [​IMG]

    Compare these with the YZ465 crank shown below.

    [​IMG]

    For this build, I have stayed with the YZ465 crank.

    Now, even with what appears to be a good crank, there are several potential issues to watch for. For instance it is not uncommon for a crank seal lip to cut a grove into the crank over the course of time. Here is an example where a grove has worn into the ignition side of the crank bearing surface. This crank was fine otherwise.

    [​IMG]

    It is not necessary to repair this. The solution is to assemble the motor without the crank seal. Then, after careful measurement, you insert the crank seal into the case at a depth that avoids placing the seal lip into the groove.

    Other issues to watch for are keyway condition and galling on the crank taper. Galling can occur when a flywheel key shears allowing the flywheel to move on the taper.

    The taper should also be checked on the flywheel,especially when mixing and matching parts for motors you do not know the history of. One of my flywheels was severly damage on the internal taper in addition to having an extra key picked up by one of the magnets!

    [​IMG]


    With a good crank selected, it is important to install it into the case without disturbing its alignment. From one of the previous pictures you can see that I chose to assemble the transmission and crank into the left hand side case first ( I think either side is OK though). When installing the crank I used a stack up of large sockets, washers and nuts to pull the crank through the (new) crank bearing.

    The idea is to pull against the crank bearing inner race as you do not want to put a side load on the crank bearing. And make sure your sockets or spacer do not impinge on the crank taper as you tighten so as not to damage it.

    [​IMG]

    more to come...

    [​IMG]
  10. anotherguy

    anotherguy unsympathetic

    Joined:
    Jun 18, 2009
    Oddometer:
    9,077
    Location:
    the hills
    I have a parts fiche in PDF for the YZ if ya want one PM me an e-mail address.
  11. wfopete

    wfopete Suffer Fools; Gladly!

    Joined:
    Aug 19, 2004
    Oddometer:
    626
    Location:
    Somewhere North of Dover, AR
    Kevin,

    Good stuff.

    Another option for the damaged seal area on the crankshaft is to go to your auto or bearing supply store and obtain a stainless steel sleeve for the diameter of said crankshaft. This as been done for years on trucks and autos where the damper area has been damaged. The sleeves relatively are cheap and EZ to install.

    http://www.vsm.skf.com/en-US/HeavyDuty/KitsAndTools/SpeediSleeve.aspx
  12. FJ_Kevin

    FJ_Kevin Been here awhile

    Joined:
    Dec 28, 2010
    Oddometer:
    487
    Location:
    Maryland ==> originally from Long Island

    Thanks much for the offer. Over time I have been able to collect all the 465/490 pdf parts manuals so am in good shape now. I have most of the printed owners manuals also. I would like to scan them when I get some time.

    Thanks Again!
    Kevin
    deafhead likes this.
  13. FJ_Kevin

    FJ_Kevin Been here awhile

    Joined:
    Dec 28, 2010
    Oddometer:
    487
    Location:
    Maryland ==> originally from Long Island
    Hi Pete,

    This is a cool idea. I will hang on to the link for future reference.

    Thanks!
    Kevin
  14. FJ_Kevin

    FJ_Kevin Been here awhile

    Joined:
    Dec 28, 2010
    Oddometer:
    487
    Location:
    Maryland ==> originally from Long Island
    Nachtflug... thanks for the note. I do have some more photos and will keep posting. Speaking of photos, I have been admiring your photos on avdrdr for quite some time. You are seriously talented in this area!

    Perhaps you can let us in on some of your techniques and/or advise on the setup you use?

    Here is the 125 experts leaving the line at Bridgehampton in 1978. I am behind the guy on the suzuki... with yamaha down the sleeve of my jersey.

    [​IMG]

    How about one of you on that kdx400?

    Thanks Again,
    Kevin
  15. FJ_Kevin

    FJ_Kevin Been here awhile

    Joined:
    Dec 28, 2010
    Oddometer:
    487
    Location:
    Maryland ==> originally from Long Island
    Sorry for my slow reply on this.

    As mentioned above, I used a so called "general purpose" magnesium rod I got from the welding supply shop several years ago. I have only welded magnesium a few times but have generally found it to be more challenging to weld than aluminum and even more sensitive to contaminants such as oil.

    Although I did try to clean my clutch cover thoroughly, there may still have been some oil residue deep within the pores of the crack I was repairing. I believe this to be the case as I was experiencing some outgassing in the puddle while welding and the outgassing left behind some pitting in the weld.

    I was also getting a fair amount of soot while welding even though I turned up the flow meter a good bit more than what I use for aluminum.

    Later I found this helpful youtube video on welding magnesium. They seem to recommend keeping the tungstun electrode very close to the puddle as you weld. Perhaps this gives better shielding. I dont think I was as close as shown in the video.

    I used straight argon. I think this is perferred over a lower cost nitrogen/argon mix often used when welding steel.

    Here is the youtube link.

    http://www.youtube.com/watch?v=weqTWwaaL0g

    Below is a photo of my repaired cover. I put extra filler into the area of the kick shaft bore for added support. It is not too pretty (note the pitting) but it did not leak either. The photo was taken after the bike was laying in the rainy ditch for a couple of days after being recovered from being stolen. It looks especially bad as my polished mag cover was already reacting with the moisture.

    [​IMG]

    Compare above with an original cover for an idea of the extra filler added,
    [​IMG]

    Twinshocker suggests that pieces from another cover be used as filler rod. This is something I would like to try as the pitting could also be due to a mismatch with the rod that I used.


    Hope this helps!

    [​IMG]
  16. mxbundy

    mxbundy Long timer

    Joined:
    Sep 15, 2009
    Oddometer:
    1,013
    Location:
    Hemet Ca.

    Thanks for the props on the seat foam. Its one of mine for sure, to my knowledge I own the only mold for the 465 seat foam!

    bundy
  17. mxbundy

    mxbundy Long timer

    Joined:
    Sep 15, 2009
    Oddometer:
    1,013
    Location:
    Hemet Ca.
    Here is a few pic of one I built for my buddy! :D




    [​IMG][​IMG][​IMG]
  18. anotherguy

    anotherguy unsympathetic

    Joined:
    Jun 18, 2009
    Oddometer:
    9,077
    Location:
    the hills
    How much better than the DG is that ProForm pipe?
  19. mxbundy

    mxbundy Long timer

    Joined:
    Sep 15, 2009
    Oddometer:
    1,013
    Location:
    Hemet Ca.
    Night and day!!! The Pro-Form really cleans up the bottom end. The stock pipe and the DG seem to over schvange the incoming fresh fuel charge and really contribute to the jetting problems for the 465.

    Bundy
  20. wfopete

    wfopete Suffer Fools; Gladly!

    Joined:
    Aug 19, 2004
    Oddometer:
    626
    Location:
    Somewhere North of Dover, AR
    mxbundy:

    I understand the 465 Pro Form pipes are tuff to get as the builder has more pressing deals with his pipes. Also, that earlier this year the builder was re-designing the 465 pipes due to fatigue and cracking issues.

    Any insight on this?