Building a 1981 Yamaha YZ465 Factory Replica...

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

  1. FJ_Kevin

    FJ_Kevin Been here awhile

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    Yes, lots of fun. I bought the jersey of Doug Childress whom advertised them on the vintagemx.us . Doug is known for building MX cone pipes.

    He made a limited run of theses and other styles, not sure if he has any left but you should be able to find his contact info on that site.

    I have a husky and CZ jersey from him to. They are all top notch vented jerseys like you would get in the '70's. He had a Belray Maico jersey that was really cool too but I didn't get that one.

    If you go next year, drop by and say hi!
    Kevin
  2. FJ_Kevin

    FJ_Kevin Been here awhile

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    Yes, terrific time!

    Nice shot of you, great form and nice roost :wink:!!!

    Had a quite a good chuckle over the "Team Lickme" photo :rofl. Those were fun times too!

    Kevin

    Even Pat says so!

    [​IMG]
  3. FJ_Kevin

    FJ_Kevin Been here awhile

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    [/QUOTE]

    I see you found WFOPete's super ignition timing write up, great!

    Here is jetting that works for me,

    slide cutout =3.5 (hand filed)
    main jet=380
    Pilot jet=45
    needle Jet=R0
    jet needle= 6DH4 (middle clip)
    DG pipe, stock porting

    If you can't get it to idle check the pilot jet to see if it is gummed up.

    If the idle hangs high then you may have an air leak. They can leak at the base gasket (my IT490 had this problem), the intake boot (cracks from age) and at the crank seals.

    Good luck!

    Kevin
  4. FJ_Kevin

    FJ_Kevin Been here awhile

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    Ok, Saturday's ride was fun although my performance was not exactly stellar.

    So I was more than a little determined to make a better showing of it on Sunday.

    Still, I had some troubles.

    We slept in an extra half hour Sun morning (us old people need our rest) thinking with practice starting so late on Sat we would have plenty of time for some extra shut eye. However, when we got to the track, practice was all ready going on!

    So now I was in a real big hurry to get the gear on, pull the bike off the truck and get started. But, kick, kick , kick... no fire! It appeared the float had hung up as gas was leaking from the carb.

    Time was running out and I didn't have a lot of options. But I did have that big blue It490 in the back of the truck. Off it came... I removed the headlight, speedo and tail light in order to get it through tech inspection. Thankfully it started right away. While I missed practice again (sheesh!), I was able to ride the bike in a nearby field. It ran good, solid clutch and good strong pull.

    Who knows what they were thinking down at the staging area. There was some nice iron down there. Now who's this guy on the trail bike? Cross country was Friday, duh!

    Anyway, it's not very often you have your own personal photographer :sweeti at the races. So I'm going to use :sweeti's pictures to tell the story...

    Here we are at the start, you can see a pair of Honda's that really flew out of the gate.

    [​IMG]

    Into the 1st turn, we see Maico guy and the Honda's. Looks like I'm back there somewhere still waking up:*sip*.

    [​IMG]


    As we round about, I am following this Yamaha. This was as close as I would get to him. He (#77) would go on to win Moto 1.

    [​IMG]


    As we complete turn 2, I seem to be around 6th and looking for an inside line.

    [​IMG]

    Next is 1st time shooting out of gravity cavity. Maico guy in 1st, #77 in 2nd, #53 in 3rd and some trail rider in 4th.

    [​IMG]

    And into the turn,

    [​IMG]

    And around we go!

    [​IMG]

    #77 and Maico guy would get away from me. But the next time through this corner I would pass #53 for 3rd place. Amazingly :sweeti caught the pass...

    [​IMG]

    [​IMG]

    I tried to run down Mr. Maico who had fallen back to second place. However, suspension was a little too soft and I almost got bucked off in a back section.

    [​IMG]

    While suspension was a bit of a handicap, the 490's power was fine and dandy!

    [​IMG]

    This is the 3rd and final time out of the cavity. You can see #53 just dropping in as I am landing on other side of the U. By this time :sweeti says announcers are commenting about some enduro guy on the move! "Cant miss him, he's on that blue enduro bike".

    [​IMG]

    From the position of my elbow, it looks like I need a quicker turn throttle!

    [​IMG]

    And there's Maico rider, within view!

    [​IMG]


    On the pegs through the turn

    [​IMG]


    [​IMG]

    Ah, but 3rd would be best I could do as I close in on the flag. Truth is I was pretty tired and just hanging on at this point!

    [​IMG]

    Next up I==> Moto 2!
  5. brucifer

    brucifer Long timer

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    Love it! :clap :lurk
  6. wfopete

    wfopete Suffer Fools; Gladly!

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    Kevin,

    It is obvious your YZ doesn't want to play.

    So:

    1. Park the YZ

    2. Put your YZ plastic and suspension on the IT.

    3. Or leave the IT plastic in place and "Be the Faaaast Guy on the Enduro Bike" :evil
  7. wfopete

    wfopete Suffer Fools; Gladly!

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    I see you found WFOPete's super ignition timing write up, great!

    Here is jetting that works for me,

    slide cutout =3.5 (hand filed)
    main jet=380
    Pilot jet=45
    needle Jet=R0
    jet needle= 6DH4 (middle clip)
    DG pipe, stock porting

    If you can't get it to idle check the pilot jet to see if it is gummed up.

    If the idle hangs high then you may have an air leak. They can leak at the base gasket (my IT490 had this problem), the intake boot (cracks from age) and at the crank seals.

    Good luck!

    Kevin[/QUOTE]

    To help out here are a couple of pics of what to look for when playing the timing game on the YZ465:

    [​IMG]

    [​IMG]





    My old YZ456G model has been sitting since last November. I never even drained the fuel out of it (Bad Boy!!) so this morning I decided it was time to do that. While I was at it I pulled the carburetor pieces to verify the jetting I had used.

    [​IMG]

    One thing that I did that I feel was a smart thing was to start out with a new carburetor with new brass. There is often a fair amount of wear and tear on these older carburetors and by starting off with a new one I eliminate that mystery aspect of tuning. I tossed the slide in favor of a new 3.5 version.

    [​IMG]

    Then ordered a variety of needles, needle jets, main and pilot jets. I had a pretty good idea of what range of jets I wanted based off of seeing what others ran in their bikes. Anyway here is what I ended up with:

    Slide: 3.5
    Main Jet: 370
    Needle: 6DH3
    Needle Jet: 247-Q2
    Pilot Jet: 50
    Needle Clip: 2nd from bottom
    Air Screw: 1.25 turns out
    Oil/ratio: Maxima 927 Castrol @ 40:1
    Elevation: 0-800ft AMSL (Height above mean sea level)

    My 456 has always run pretty good down low (read crisp) and I like that. Strangely enough this was with a #50 pilot jet (most folks use a #40 or #45). Mid range jetting may be a little thick (rich) but not bad and top end is a touch toward the leaner side too but hey, how long are you going to be wide open on a YZ465 (and live to tell about it)?

    I’ve always been happy with my plug readings. This plug has about 6 hours on it:

    [​IMG]

    [​IMG]

    The spark plug is a NKG B8EG but I don’t have a problem running a standard run of the mill NKG B8ES.

    Now I don’t pretend that I have the ultimate YZ465 jetting. I’m sure that it could be dialed in better, but the bike starts good, runs clean & has never fouled a plug. I credit the timing as much as the jetting. As far as I know the porting is stock.

    /
  8. FJ_Kevin

    FJ_Kevin Been here awhile

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    Yeah, I know and not good given the subject of this thread:lol3!

    I found my clutch slip issue was a result of using 465 springs with my 490 clutch assembly. The 490 pressure plate has a deeper well where the springs fit. The 490 springs are longer by the same about (~0.1" if memory serves).
    My 465 springs were not compressed enough in the 490 pressure plate so eventually clutch slipped.

    Here is a comparison,

    [​IMG]

    I overlooked this when doing the clutch swap (oddly the part numbers are the same, maybe 465 number has been superseded?).

    I put in Barnett heavy duty springs and have noticeably stiffer pull at the clutch lever and no slip now. Cant believe I missed this! Maybe I have that Adult ADD that's been going around.

    My start problem was easy and self inflicted too. When playing around with jetting, I was swapping carbs back in the spring. One of them had a new float needle and seat while the other did not. Of course I got distracted by other things (like other old motorcycles :deal) and forgot which was in the bike. My carb overflow at Unadilla was from the carb with old seat assembly.

    After putting in a new float needle assembly the bike started on 1st kick, cold with just choke on :1drink. Ran great up until the time I hurt my knee.


    Speaking of which, the torn cartilage in my knee shifted back into position. All it took was a snap, crackle, pop and temporary lightening bolt of pain :eek1!

    So after 1 week + on crutches, I can walk again. I am getting orthoscopic work on Monday. Wont fix all my problems but will get me going again I hope, torn ACL will not be repaired for now.

    In the mean time I'm looking into knee braces. There seems to be a lot of choices out there.

    Thanks for adding your jetting info!

    [​IMG]


    And MRI for your shoulder tomorrow, right? Good luck with that!

    Kevin
  9. wfopete

    wfopete Suffer Fools; Gladly!

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    MRI results are in:

    1. Nearly complete tear of the supraspinatus.

    2. Dislocated bicep tendon.

    3. Tiny Peripheral cyst (where, what I don't know).

    I understand that 1 and 2 often go hand in hand.


    Dang Kevin, I was going to suggest we try to make Unadilla next year and race in the same class. But between our bikes and our bodies all we may able to do is play spectator. :freaky

    Don't know if you have this but here is PDF FILE it has the stock carb jetting and list optional jets for your bike.

    http://vintage38.tripod.com/YZ250_490INFO.pdf


    here is the main page also with lots of other yz and mx info

    http://vintageyzinfo.tripod.com/index.htm

    I got this off of the vintagemx.us web site.
  10. richardktm

    richardktm Richard KTM

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    Isle of Man
    I loved this thread in the build process, now its even better that you're racing and getting results:clap
    I really like the indepth engineering stuff swapping between the 490 and 465 to get the ultimate bike.

    I only owed the 490 in my youth so never got to ride the sweeter handling 465, its great to see you swapping between bikes during the races.

    I remember racing my mates around the local tracks back when i was 15 or 16 with this bad ass firebreathing yam, there's nothing more entertaining than a small fast bike in the corners and a big fast bike on the straights.. it's the basis of all epic motor races.

    I remember mum bought me a book called Yamaha Dirtbikes for xmas around that time the author was Colin Mackeller, an absolute must read for any fans of that era.

    keep up the good work and ride safe.

    rich:thumb
  11. FJ_Kevin

    FJ_Kevin Been here awhile

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    Wow Pete,

    That sounds like a pretty serious set of injuries. I hope they can fix all that for you and that the recovery wont be too bad.

    I'm still hoping that Unadilla will be in the cards next year. Had my knee surgery Monday. It seemed to go well but I am more sore than the 1st time. I guess it should be expected as they had more work to do. I go back to see doc tomorrow. Told me some details after the procedure but I was too groggy to catch all of it. Still, I think I will be in OK shape once the swelling goes down.

    Good luck with your stuff!
  12. FJ_Kevin

    FJ_Kevin Been here awhile

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    Richard,

    Glad you like the thread and appreciate the kind note. The 465 and 490's are both fine bikes I think. That MacKeller book is tough to find now. I have a section from it covering the enduro models (very good as you say) but have never seen a copy anywhere. I bet you have plenty of great memories from racing in your youth, a great experience I'm sure!

    And now so many years later, still lots of fun. All the guys I've met at the races are always very friendly, more than happy to help when they can. What a bunch of nice guys I've met.

    There is a lot more to come so stay tuned. It takes a while for me to pull all the photos together. There is more on Unadilla plus I am building another hot rod 490 motor plus all kinds of other stuff I hope folks will find interesting.

    No real master plan here other than to have lots of fun :wink: !

    Kevin

    [​IMG]
  13. Kevin K

    Kevin K Adventurer

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    Over the Rewind weekend I had to take close to 300 pictures with my canon 20d. Something happened with my memory card as the pictures won't upload to my or anyone else's computer. When I put the card back in the camera the word "error" shows on the little LCD. I know they are still in that memory card somewhere. Does anyone have a solution to getting my pictures? I'm not just upset that I can't get the pics off, but I'm bothered that I carried that stupid camera around and watched motos through a 200mm lense rather than sitting back and enjoying watching the old bikes do thier thing.


    I am going to be riding next year as many classes as they will let me race ,(judging by how many motos Cody Kessler rode, they at least let you ride 15 classes) . I'd also like to do Fridays hare scramble.,
  14. cedric

    cedric Been here awhile

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    I've been enjoying this thread and hope one of you 465 gurus can help me out. I'm hoping to put an aluminum swingarm on my 1980 XT 250 in the future to replace the stock steel one and hopefully (with a shock swap) get some more travel in the process too. It seems like one from a 465 might be a good option. I'm wondering if one of you has one kicking around and could take a few basic measurements for me? Looking for the length of each of the three sides of the triangle as well as the widths (overall, center and each side) at the swingarm pivot. Thanks, appreciate any help or advice on this.
  15. FJ_Kevin

    FJ_Kevin Been here awhile

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    Unadilla Moto2

    Well I finally got a moment to continue on here. These doctor visits and issues surrounding my knee have keep me busier than expected.

    One of my main issues is that I have no ACL and so my knee is not as stable as a normal knee. I have been investigating knee braces as a means of avoiding a repeat of this injury and another surgery. The good news is I found something that looks promising. I wound up getting measured and fitted last week and now have a brace on order. I'll provide some details on this in a later post in case someone else is dealing with a similar issue.

    Anyway, turning back to Unadilla, we first recall the surprise 3rd place finish in moto 1 while riding the IT490 of all things.

    Not only did it surprise me but it surprised plenty of other guys in my class. And they let me know it in the staging area for moto 2.

    You see in the 1st moto, riders were called to the gate according to sign up order. I signed up late so was called late. Showing up with an enduro bike I hardly drew any attention. OK, perhaps a snicker or two but that's about it.

    However, for moto 2 they called the riders according to finishing position in moto 1. Being the 3rd guy called out I was getting plenty of attention, mostly in the form of steely stares as I rolled up with that big blue IT! And I got plenty of ribbing too.

    One guy said it was very unfair how I was blinding everyone behind me with my turn signals and brake light and and that was reason he couldn't keep up :lol3 . Another was poking fun at my tool bags and asked if I had my lunch back there :D. Yeah, these guys were quite funny:1drink.

    OK, so I was teased a bit but one nice thing about being called early was that I could clearly see and size up the two riders that had beaten me. And I could choose a place on the line where I could keep my eye on them!

    I also had another secret weapon to draw inspiration from that I have not discussed until now. Although I was unable to refresh my skills at an MX school, I was able to get my hands on this...

    [​IMG]

    That's right. The Technique of Motocross by the great Swedish Grand Prix star Ake Jonsson. I had lost my original copy from 1974 but my wife miraculously found a copy in a Louisiana library and had it shipped in just in time for me to re-read and study before MX Rewind. And study it I did!

    [​IMG] [​IMG]

    With Ake's advice in mind, I carefully and confidently selected a starting position with a straight line groove leading out of the gate for maximum traction.

    I paid particular attention to this as I knew the period immediately after the start would be vital. How did I know? It's all right here on page 183...

    [​IMG]

    Let's now turn to the photos to tell the rest of the story.

    Here we are, all lined up for moto 2. Directly on my left is #77, winner of moto 1. On my right is 53 (4th place) and #7 (2nd place) on the red Maico. You can see this is all very serious business. Everyone has their eye on everyone else. And I've made up my mind that there is no way that old f'er on #77 is running away from me!

    [​IMG]

    But darn if I didn't get another so-so start.

    [​IMG]

    Around we go and these guys are getting away from me!

    [​IMG]

    [​IMG]

    [​IMG]

    Through the 1st corner I'm back in fifth position already :puke1.

    And then, from Ake's book, I remember "Do not wait to pass, do it right away!":deal.

    So I did.

    The first time out of gravity cavity I've moved into 4th and right behind that crafty #7 in 3rd. But I'm not looking at him, I'm looking at #77 in 1st.

    [​IMG]

    I out drag and out brake the Maico into the turn for 3rd just like Ake said to do :1drink!

    [​IMG]

    And now #77 is caught up in the grooves and in my sights :evil!

    [​IMG]


    But no, #79 slows more than I expect and I run into his back wheel :eek1!


    [​IMG]

    This was a big mistake on my part. Will I fall down or will I stay up :eek1???

    Can't blame Ake for this either as he warned me about this situation right here on page 191 :deal!

    [​IMG]

    Somehow I did not fall but while I am regaining my composure, #77 is hooked up and on the gas :puke1!

    [​IMG]

    Not only that but crafty #7 takes advantage of my misfortune and re-passes me :puke1:eek1:puke1.

    [​IMG]

    With #77 and #7 off and running I regroup in 3rd position and give chase :norton!

    [​IMG]

    By the end of lap 1 #7 is within sight again :wink:

    [​IMG]

    ============

    Oh my! What's next? How will it end?

    Stay tuned! More to come....
  16. wfopete

    wfopete Suffer Fools; Gladly!

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    You're killin' me! The suspense is too much!
  17. brucifer

    brucifer Long timer

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    Dang you Kevin! I'm on the edge of my seat here! Seriously! :lol3
  18. Foot dragger

    Foot dragger singletracker

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    The camera may be full?
  19. mxscot

    mxscot n00b

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    Hi Kevin, great to see the race pics and reports!

    Now that my big adventure to the Farleigh Castle "Field of Dreams" has come and gone I've got a bit of time on my hands to update the story of my own rebuild as promised.

    [​IMG]

    The frame was repaired then grit blasted and powder coated. The front forks were in a bit of a state but a good clean out and new seals and bushes and a cosmetic grit blast sorted them out.
    The rear shock was sent off to Pro-Action for a re-valve job to suit me and some modern internals added. I also added a heavier progressive spring.

    The cylinder bore was well worn so a re-bore was done and a new Wiseco piston went in.
    The bottom end was in good nick, the gearbox and clutch were like new so I left well alone.
    A full new PFR exhaust system was obtained and fitted.....along with a whole heap of new cables, plastics and bits and pieces.

    [​IMG]

    [​IMG]

    I prefer the white euro style so the old yellow was binned. Even though it is a YZ465H 4V4 I always preferred the older style Yamaha speed block decals so I got the 1980 tank stickers.

    [​IMG]

    [​IMG]

    Last job was getting the carburation sorted out and the bike run in ready for the Farleigh Castle Vets MXdN run over the 13 -15 September.
  20. mxscot

    mxscot n00b

    Joined:
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    So off we went to the south of England for the big event. :freaky

    After scrutineering and sign on there is the official photo shoot:
    [​IMG]

    Racing was on the Saturday and Sunday. First Timed Practice for gate pick. then two 5 lap races each day round the historic circuit.

    Ready for practice:
    [​IMG]

    Racing:
    [​IMG]

    Results? well I didn't set the heather on fire but was 32nd overall in the over 50's class. A class incidently won by Jim Anderson from the USA who shipped his bikes over for the event! Well done Jim!

    As a souvenir of fulfilling the dream I got a few signatures ( Chuck Sun, Roger Harvey #7. Jan Geboers, Johan Boonen #3) on my race shirt

    [​IMG]

    On reflection a bit of familiarisation would have been a good thing before getting into the action but time was a bit tight in the end. I need to learn how to get this thing to turn. Also half way into the races I started hearing this strange noise which I hadn't come across before on a motocrosser - knocking, pinging, detonation. So I'll have to get that sorted out.