Building a 1981 Yamaha YZ465 Factory Replica...

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

  1. athomerecords25

    athomerecords25 Banned

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    I would like to see this also, not that the porting would fit me or my riding level (I think Eric Gorr is the best at porting YZ400, YX465 and YZ490 Cylinders). I don't think he would have the equipment to be able to provide a Port Map or Cylinder Port Scan, and taking it to an Engineering Facility to have it done would cost a small fortune.
  2. anotherguy

    anotherguy unsympathetic

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  3. athomerecords25

    athomerecords25 Banned

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    FJ_Kevin,

    Could you please post up a picture of the Clutch Hub Nut from your 1981 Yamaha YZ465? Thank You in advance?

    Edit: scratch that I found a pic online. I have the right nut and washer (thought I had lost them and was trying to put on the wrong one). For some reason the Shaft isn't sticking out through the clutch hub, it is way too short, it was fine before I took the clutch off. I did something wrong. Oh well back at it tomorrow.
  4. FJ_Kevin

    FJ_Kevin Been here awhile

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    Well I cant believe it has been a month and a half since I last posted anything here.

    Aside from the usual life events, I have been real busy trying to get things ready for the upcoming season. It's easy to spend all the time working on projects without leaving any to report on the progress.

    But wow! I can see I really need to address that huge whooper of a story I told about the OW41 cylinder in my last post!

    Haha, yup, that was a total fabrication on my part :lol3 originally put together as a gag to one of my old racing buddies to get him interested in joining me in some vintage MX this year. It worked so well on him that I just couldn't resist having a little fun with my friends here :eek1!

    So here's the real story.

    That OW cylinder is really just an ordinary IT465 cylinder for a second yz465 I am building (and one that my buddy might ride). You can tell this as it has the rubber noise isolators in the fins.

    To help make this caper fly, I purposely kept the image of the cylinder in the oven small in the previous post hoping no one would notice this :evil. I knew with a large image someone here would have thrown the BS flag on me!

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    As for the "special OW" cylinder stampings,

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    I simply ground the original casting marks off and then did a little finishing with a hand file. After that it was just a matter of searching the shop for my old stamps (see below).


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    My original intent was to stamp Hannah on the cylinder but I was missing the letter "H". So that's when I got the idea to look in the book to see who else could have been riding YZ465's at the time. That's when I spotted Rex Statens name on the very same page as a photo of the factory OW, what could be better?

    The reason I stamped "R X instead of "REX" was because I was also missing the letter "E" :deal.

    In any case, I hope my BS story hasn't offended anyone and besides half the fun of vintage MX is the BS :wink: that goes along with it all!

    And if I did offend someone, then you will be very pleased to know that I am sore as hell today after falling off the 465 yesterday at Budds Creek while racing in the post vintage 50+ class... more about that later :freaky!

    So now that I have confessed and while still on the topic of fakes, forgeries and fish stories, here are a couple of more.

    First is an update on my fake Bell Motostar (really a $100 snell 2010 HTC ) helmet I posted earlier. Here it is again after adding the Bell stickers and as it sits next to my old Moto 5 on left.

    [​IMG]


    And then there is this ebay listing for a factory Suzuki Motocross bike (dont worry, not mine!). This has generated a lot of commentary on the usual vmx web sites. Earlier listings had a BIN price of $250K... seems about as fishy as my story :-)

    SUZUKI RH 250 HISTORIC VINTAGE WORKS FACTORY MOTOCROSS
    http://cgi.ebay.com/ebaymotors/SUZU...sPageName=STRK:MEWAX:IT&forcev4exp=true#v4-39

    [​IMG]

    If the Suzuki factory bike is too much for you then consider Rodger Decosters expansion chamber for just $3000 here...

    http://www.ebay.com/itm/Suzuki-RN72...Parts_Accessories&hash=item3380dc9871&vxp=mtr

    [​IMG]

    A fishy photo from the past?

    [​IMG]


    Next up... the YZ465 and old guy head to Budds Creek for vmx racing :eek1

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    Uh oh :huh!

    [​IMG]
  5. anotherguy

    anotherguy unsympathetic

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    I kinda feel like old Flounder.
    [​IMG]

    “Flounder, you can’t spend your whole life worrying about your mistakes! You fucked up… you trusted us!”
  6. wfopete

    wfopete Suffer Fools; Gladly!

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    Really Kevin, April 1st is only a few days away. You should have waited until then.

    I don't know about the rest of the photos but #22 is Magoo showing the AMA that he could ride a track "backwards".

    The 465's in the truck and the Budds Creek are more fakes no doubt; carefully photoshopped.
  7. Mr. Carts

    Mr. Carts Been here awhile

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    I just picked up a IT465 and have a oil question.

    What oil are you using with for your 40 to 1 premix?

    My IT465 manual says Yamaha R at 16 to 1.

    Thanks
  8. FJ_Kevin

    FJ_Kevin Been here awhile

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    Hey,no way!

    I know well seasoned, grizzled veteran when I see one (yeah, I've read your posts!).

    I will soon be starting on a Moto Bitsa composed of a collection of left over husky, maico, ktm, kawasaki and yamaha parts and will be needing some sage advise to make it work so please stick around!

    Of course, it will have some kind of yz/it490 motor in it.

    Here are a couple of teaser photos. First one is gathering up possible parts to use (thats a maico tank on there).

    [​IMG]

    Here is another mock up with ktm swing arm, husky tank and some yz forks.

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    Plenty to figure out but it should be fun.

    Here is another bitsa found on the web. This seems to have a husky frame too.

    [​IMG]
  9. FJ_Kevin

    FJ_Kevin Been here awhile

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    I really do deserve that, ouch! :wink:

    BTW, I made a new observation relating to the kick starter gear issue. The problem turned up on the 2nd YZ I have been working on and relates to the tang on the gripper spring on the kick gear. A problem here caused the kick gear to engage when the motor rotates backward (like in kick back).

    It's easy to miss, will post some photos with the details.
  10. FJ_Kevin

    FJ_Kevin Been here awhile

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    I seem to be doing fine running Amsoil Dominator mixed 40:1 and sometime 50:1 .

    The shop down the street from me has it so I mainly use it out of convenience.

    I'll let the others chime in with their opinions.
  11. anotherguy

    anotherguy unsympathetic

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    My 465 has survived a long time w/BelRay H1R @32:1 in leaded and oxygenated race fuel. Second owner and second oversize piston. Crank's number 2 only because I wanted to balance it. #1 had plenty of life in it when I took it apart.
  12. FJ_Kevin

    FJ_Kevin Been here awhile

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    They had a pretty good turn out at Budds Creek and I was fortunate to find a bit of time to stroll the pit area and take some pictures.

    I'll start off with the euro bikes.

    This KTM 420 caught my eye right away. It looked well cared for.

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    A couple of CZ's also showed up.

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    There were a good number of maicos, here is one of them.

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    There were two of these neat little ducati dirt bikes at the same trailer. Too bad I did not get to see them run.

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    And a Benelli!

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  13. dtysdalx2

    dtysdalx2 PITA but useful

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    That looks so cool. Man I need to find some vintage MX races this summer.
  14. FJ_Kevin

    FJ_Kevin Been here awhile

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    Of course there were plenty of japanese mx bikes too, including many alloy tanked Suzuki RM's

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    This red framed honda looked pretty tricked out,

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    CR250

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    More air cooled Honda's, single and twin shockers.

    [​IMG]

    1979? YZ250

    [​IMG]
  15. FJ_Kevin

    FJ_Kevin Been here awhile

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    Yes, you should go. It was great fun!
  16. FJ_Kevin

    FJ_Kevin Been here awhile

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    OK, I dont have too much time at the moment but perhaps I can start the report on my experience racing the big bad YZ465 Factory Replica that has been the subject of this thread :eek1.

    Now keep in mind that this is my first motocross in 32 years. Yes, it is true, I am an old guy!

    One thing for sure, the March 23rd event came up pretty fast here in Maryland (way too fast!). Especially as the weather has been cold and there have been few opportunities to get out on the bikes. In fact, the 1st time I started any of the bikes up this year was just 2-weeks prior to the event.

    So I guess you could say I wasnt going into this so well prepared :lol3.

    On the other hand, I did at least exercise fairly regularly, mostly by riding the indoor trainer. My wife is a serious cyclist and rides 5-6K a year. I have to do this so I can have even a glimmer of hope of riding with her in the spring.

    She is on the left, I am on the right. Notice how her bike is placed ahead of my bike as this is the usual position on the road :puke1.


    [​IMG]

    Since I am new to this vintage racing stuff I was not exactly sure which vintage racing events required a racing license. I decided I would join the AHRMA group this year as they seem to be the fairly active in my area (I have since learned of others).

    On the application they ask for your top 3 picks for racing number. Figuring that all the double digit numbers would be taken already, I made my first choice 640, the same number as used in my very first race in 1976 and the one I received when they mailed me my license. Hows that for nostalgia?:D

    [​IMG] [​IMG]
    Photos from 1976 with race number 640


    And now a photo of the 490/465 bikes with new numbers in place. They do look the business don't you think?

    [​IMG]

    Ah, but still more work to do. Once the numbers went on, more time doing final checks and adjustments.
    Then the matter of pulling the gear together, assembling a toolbox, gathering spares, fresh gas and on and on.

    With so much to do, I found myself working right up until about 10pm the night before the race, just like the old days :deal.

    To save time I thought it best to load up the bikes the night before.

    [​IMG]


    While my intent was to race the yz465, you can see I took the IT490 also. This was so I could swap parts if anything failed on the 465 as many of the parts are interchangeable. This proved to be a good move :evil .

    By the time we got to the track the next morning there was only 15 minutes before end of sign up. There was a bit of a line but it moved fast. I am happy to say that the Budds staff was very friendly and helpful. And it looked to me that they kept the sign up open well past the official closing time and long enough to accomodate all comers.

    The other racers were great too and were really helpful in showing me the ropes.

    It seemed there were several possible classes that were open to me. Being away for so long, I thought signing up for just the 50+, intermediate, post vintage would be more than enough for 1st time out.

    The post vintage class seems to include most MX bikes up until about 1984 and with no disc brakes. They ran all displacements together in my age category. So me and my 465 were lined up together with guys running 125's, 250's and a few other open class bikes. Good for me.:wink:


    Since we got to Budds later than I had hoped, I found there was no time left after sign up for me to walk the track. This may have been a good thing as I was already a little worried after viewing some of the obstacles from the pit area.

    Here again is that photo that I posted earlier.


    [​IMG]

    The size of the hills and jumps (compared to the people) had me thinking about getting back in the truck and heading home!
    My wife was concerned too but didnt say anything so as not to make me nervous... haha, too late!

    I decided my plan would be to pick someone out to ride behind in the practice sessioin so I could pick up some lines and get a sense for how fast to approach some of the jumps. I have no trouble admitting I was a bit freaked out over these! So with plan in place, I went back to the truck to suit up. I then started the bike and rode down to await my groups practice session.

    My wife snapped this picture of me with the replica OW 465 holding my replica Bell Moto Star (thinking what the hell am I doing?:lol3).

    [​IMG]


    I am seriously hoping that somehow the use of my old race number will allow me to channel my inner 17 year old (like below).

    [​IMG]

    Anyway, by this time in the morning the temperature was finally warming up and the 465 was running very well. I was hoping it would as the bike had felt a little lean earlier in the week when the temps were running in the low 30's. I hadn't had the time to fatten up the jetting so really took a chance on this point.

    When I finally rolled onto the track I found the dirt to be moist and traction excellent, the 465 was snappy and really hooked up.

    Unfortunately, I only got a few turns in before the rear wheel locked up. I skidded to a halt thinking my gearbox was seizing or something.

    But no, my tire had gone flat and the sidewall had blown right off the rim. Not only that but the tube had wrapped itself around the wheel, the swing arm and the rear brake lever like a big rubber band. Now what???

    Practice was only 20 minutes and I still had not seen the course yet. I knew the only option was to leave the 465 on the side of the track and go get the 490 off the back of the truck, quickly!

    This all ate up time of course. In the end I got 3 laps in. Not enough to learn the track but enough to get me settled down and thinking I could get around without completely embarassing myself.

    [​IMG]

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    I have to say, these big bore Yamaha two strokes are such fantastic motors. That 490 just ripped up the hills and had great drive out of the corners.

    On the other hand, the IT suspension, while cushy on the trails, was way too soft for an MX track. I found myself bottoming in several sections. In fact, the shock bumper was totally gone after the pracice session. I guess it needed to be replaced anyway.

    And for some reason I found the track not as intimidating once on the bike. I was actually enjoying myself. I could even feel some of the old instincts already kicking in. That was neat!

    But I still didnt know the track very well. Several of the jumps at Budds are blind and I wasn't always sure what was on the other side.

    One thing I was sure of was that fitness would be a big problem. My arms pumped up quickly and I was left breathing fairly heavy after just those 3 laps.

    More to come...
  17. dtysdalx2

    dtysdalx2 PITA but useful

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    Geez, blew out the rear tire already?? What psi did you have?

    Thanks for sharing...:D
  18. FJ_Kevin

    FJ_Kevin Been here awhile

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    continuing from last nights post...

    With the practice over I had some quick repairs to make. I rode the IT back to the truck and removed the rear wheel. I then carried it down to the track to swap it into the YZ.

    However, when I removed the wheel from the YZ a brake shoe liner fell out. Somehow it had separated from the brake shoe!

    Has anyone seen this before?

    [​IMG]

    Ah well, replacing the wheel allowed me to roll the bike back to the truck but I would need to fix that brake shoe. I had fitted a YZ490 wheel to the 465 so knew the IT shoes would fit. So a quick switcharoo and I was back in business.

    [​IMG]

    With all this going on I missed the riders meeting and all the instructions that go along with that. Thankfully another racer clued me in on the most important details and what moto number I would be going off in. Like I said, the folks I met this weekend were really terrific.

    As the time for my moto approached, I told my wife I was going to take it easy and follow someone else around as I still didnt really know where I was going and I kind of wanted to make it home in one piece. She liked this idea.

    I then rode down to the start area and selected what I thought would be a good position on the gate. My moto would be five laps, I knew I would have a tough time making that.

    It's funny, while sitting at the gate I couldn't help thinking how it looked exactly like I remembered from so long ago. It is one of those jobbies that falls towards you. If you go too soon you risk pushing the gate back up. You get stuck while everyone leaves you behind. And while the gate falls together they are independent in the sense that the guy next to you can push his gate up while yours can still fall cleanly.

    Although the gate was familiar, Budds uses a traffic signal light to inform riders when it is about to be "go" time. It goes red to yellow to green at which time the gate is supposed to drop in 2-3 seconds. In my day, someone (a girl if you were lucky :wink:) held a 1 minute card which she turned sideways in the final 10 seconds or so before the gate fell.

    Anyway, the light goes green, the gate drops and that 465 (with my fat as$$ on it) just rockets off the line and straight into the first turn... in first place!

    I didnt see another wheel, a fender or anything. Just wide open track. I didnt know if the 1st turn was 90 degrees or 180 degrees (it was 180) but somehow I made it through.

    At this point I decided I better keep gassin it so as not to get run over right away. Somehow in all this excitement my wife had enough composure to take this picture of me leading out of the first turn with some other old geezers snappin at my heels. :freaky

    [​IMG]

    With 3 quarters of the 1st lap complete I finally remember my plan to follow someone so I could learn the track. So I look over my shoulder to let second place go by but second place was not there. Instead I saw gap!

    I then decide I am just going to just go until some fast guy blows by me. But at the end of the 1st lap the lead is growing and at the end of the 2nd lap the lead is larger still. Finally I figure out whats going on here, haha, the other guys are all 50+ too :rofl.

    It didnt matter though because by this point I am in trouble anyway. There are 3 laps to go and I am getting tired. It is remarkable how much energy it takes to ride a motocross bike around a track like Budds. The 8 motos that went before us really roughed things up for us oldtimers.

    Of course you can guess what happens next. Yes, I fall down. :muutt

    2.5 laps in and my front wheel rolls over a rutted down hill berm. My wheel washes out over the other side and I go down. And down kind of hard, like "uuhhuggg" hard! I definitely remember thinking how hard a hit it was.

    On the bright side, I didn't feel any pops indicationg a break or dislocation :1drinkand I was able to get myself up. I asked a nearby track worker for help in lifting the bike as it was dug into the hill a bit and I did not want to hurt my back lifting it on my own. It wasnt really damaged other that the front fender being curled under like a cheese doodle.

    Trying to start it up wore me out even more. I did get it going but decided the best thing to do was to call it a day while I was still relatively OK.

    So here are some take aways for me :lol3.

    First, I was really pleased about how well the bikes performed. The YZ and IT Yamahas are terrific race bikes and both make excellent choices for vintage racing. It was very satisfying to have them go so well after all the effort to rebuild them.

    After getting over my initial fears, I was really starting to warm up to the Budds Creek track. It wasnt as dangerous as it first appeared to me. It was a well run event with good facilities. They even have a sprinkler system to keep the dust down.

    Although I cant say I put any really solid laps together, I was able to string together a few corners and sections that reminded me of what it was like to race in my youth. That felt wonderful!

    I have also concluded that its real important that I not fall down too hard. This means I have to be in better shape, practice more and be satisfied riding at a comfortable pace without regard to placing :puke1 :lol3.

    The racers and oldtimers that participate in this are a real nice bunch. Hats off to them for getting out there on the track and for getting these old bikes into race condition

    The next race is April 13 in WV at a track called Tomahawk. It is being put on by a group called ACR I think. I have never been there but I'm thinking about giving this one a try too.
  19. FJ_Kevin

    FJ_Kevin Been here awhile

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    Yeah, I know. I was running about 15psi. I am pretty sure I had the rim locks tight but perhaps they were not tight enough. Maybe the wheel spun in the tire and ripped the valve stem? I'll take a good look at it over the weekend.
  20. brucifer

    brucifer Long timer

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    That's awesome Kevin! I love it. Too bad about the crash but at least you and the bike were okay.

    As for the separated brake shoe--I have seen that a lot where the bike has not been used for long periods of time, usually years. But I haven't seen it happen to one being used regularly. It may have something to do with water intrusion and the aluminum part of the shoe oxidizing and loosing adherence to the lining over time.