Fixing the 1980 yz465

Discussion in '2 smokers' started by mudmantra, Jun 19, 2012.

  1. mudmantra

    mudmantra Been here awhile

    Joined:
    Jul 6, 2009
    Oddometer:
    364
    Location:
    Humboldt
    I checked the air screw. It was at 1 and 7/8's. Started right up and ran fine until it got hot. Then the idle rpm's raised a bit higher and would fluctuate a bit. I lowered the idle speed and set the air screw for the smoothest response, without any rpm hang, 1 and 1/4 out. Tested the bike and it runs strong. I'll Start it again cold, and see how it works.
    #81
  2. anotherguy

    anotherguy Long timer

    Joined:
    Jun 18, 2009
    Oddometer:
    15,491
    Location:
    the hills
    OK as long as that checks out the pilot size is good.

    My YZ is kinda finicky about pilot size. I change it when the seasons change 'cause it just starts and runs better. I run race fuel so my sizes won't help you but it was something I found over time. I've had the YZ a long time and it took some time to get in sync with it's wants and needs. Typical big bore air cooled smoker. Moody like a hot woman and just as rewarding when everything's good. The best thing for it and your relationship with it is to ride it as much as you can. Keep notes and refer back to them when issues arise.

    I need to get out to the farm and ride the beast. :cry
    #82
  3. mudmantra

    mudmantra Been here awhile

    Joined:
    Jul 6, 2009
    Oddometer:
    364
    Location:
    Humboldt
    Yes good notes help. I was keeping them, but forgot to put on the date. So I couldn't figure out my last jetting change. Now I put a date on them, but still get my notes mixed up with my notes for my YZ490. :huh :lol3 I think I have the jetting pretty close. I started with a 50 pilot jet and went to a 45. I think I can get a 47.5 pilot. I might try that too. Might be just right. Every work day I start the YZ465, test ride and try something. Just a few more things to dial in, and I'll take it up to the woods. Completely different type of riding, so I'm sure I'll have to make adjustments.
    #83
  4. mudmantra

    mudmantra Been here awhile

    Joined:
    Jul 6, 2009
    Oddometer:
    364
    Location:
    Humboldt
    Well all this ripping around and now the clutch is starting to slip. New list of things to fix. Replace the clutch discs and springs. Better replace the old clutch cable. while I have the side cover off, I'll replace the clutch side crankshaft seal too.
    #84
  5. mudmantra

    mudmantra Been here awhile

    Joined:
    Jul 6, 2009
    Oddometer:
    364
    Location:
    Humboldt
    Still fixing stuff. Installed new clutch cable, clutch fiber plates and springs. After looking at the clutch, I should get new steel plates too. It's all together now, but I'll order the steel plates to have on standby, in case I just have to fix it. New front brakes and Yamaha brake cable. New rear fender drilled and ready to install. Plastic's are off to spot paint and seal the frame. Still have a little more painting to go, but it's raining like crazy now. Bad painting weather. Might be a good time to install new fork seals and change the fork oil. :norton
    [​IMG]
    #85
  6. mudmantra

    mudmantra Been here awhile

    Joined:
    Jul 6, 2009
    Oddometer:
    364
    Location:
    Humboldt
    A little more work done. Checked the forks, and it looks like I'd have to destroy the dust seals to remove them. The seals aren't leaking, so I only changed the fork oil. I remove almost 500cc's from each, I don't have a manual, so I just added 500cc's to each leg. It should work for now. The old fork boots were ripped. Installed new black fork boots. The steering bearing felt stiff. I checked the lower was rusted beyond use. Ordered new bearings. Ordered new handle bar to replace the one I bent. Fit checked the fender, seat and tank. Getting closer.
    [​IMG]
    #86
  7. RKM50

    RKM50 n00b

    Joined:
    May 22, 2012
    Oddometer:
    7
    Are the forks 43mm? On my '83 490 with 43mm forks each leg took about 19 oz (560cc). I believe the oil level is 6.75 inches down from the top when measured with the fork collapsed and no spring in it. I used 15wt, I think stock is 10wt.
    #87
  8. mudmantra

    mudmantra Been here awhile

    Joined:
    Jul 6, 2009
    Oddometer:
    364
    Location:
    Humboldt
    No. I think they are the 38mm, the stock 1980 YZ465 forks. I just looked at the level and it looked like 4 inches from the top. I hope to find the actual spec's for the level before I ride it. I like the 83 YZ490 better than my 82 YZ490. It still has the rugged original YZ490 look, but it's 10 lbs. lighter. Well on the bright side, I have more incentive not to have my YZ490 fall on top of me. :lol3
    #88
  9. mudmantra

    mudmantra Been here awhile

    Joined:
    Jul 6, 2009
    Oddometer:
    364
    Location:
    Humboldt
    I just installed new steering bearings. The bottom race was stuck , I finally used a welder to build it up just enough to pop it out. Installed new handle bars to replace the one I bent. Actually, the old bars survived without being bent. One of the lower handle bar holders was bent instead. Lucky for me, it's the same part as my spare YZ490 holder.
    [​IMG]
    #89
  10. mudmantra

    mudmantra Been here awhile

    Joined:
    Jul 6, 2009
    Oddometer:
    364
    Location:
    Humboldt
    Back to waiting for parts again. :norton I removed the clutch to change the gear side crank shaft seal. Then I discovered a screw had backed off and contacted the clutch gear. This caused some minor damage to the seal hold down plate, plus the upper plate. I pulled some plates off a spare YZ490 motor and replaced the screws. I noticed that the kick start idle gear was a little damaged, I selected a better one from my spare parts. I then checked the kick start assembly. The main spring was on it's way to being sheared off. The retaining washer was deformed, and needed to be replaced. So I needed a few parts. I ordered a new friction spring just in case too. In 1983 Yamaha has new part numbers for the kick starter assembly parts and idle gear. The new parts were used all the way up to the WR500. I wonder if they are any better.
    [​IMG]
    [​IMG]
    #90
  11. Racerjoe

    Racerjoe n00b

    Joined:
    Jun 10, 2010
    Oddometer:
    4
    I had left you a message on the other thread about this bike. then I found this one....I would like to hear more about the head and cylinder work you had done... Can you tell me more? What real changes did you get? I figure it was much stronger as you bored and built top end at the same time correct? Did it move the power lower or spread it out ect...??? I bought a beater and tore it down to the bare frame and replaced most everything as I put it back together. Ridden it a couple of times but need to fix the pinging and get the carb right.

    [​IMG]
    #91
  12. wfopete

    wfopete Suffer Fools; Gladly!

    Joined:
    Aug 19, 2004
    Oddometer:
    850
    Location:
    Somewhere North of Dover, AR
    Hey Mudmantra, I don't know if I ever PM'd you on this so it might be old news about my 465 jetting:

    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. 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: 0-800 ft. AMSL

    [​IMG]

    [​IMG]

    [​IMG]

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

    I’m sure that it could be dialed in a bit 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.

    Right now the motor is waiting for a IT lower end and a visit to Eric Gorr.
    #92
  13. wfopete

    wfopete Suffer Fools; Gladly!

    Joined:
    Aug 19, 2004
    Oddometer:
    850
    Location:
    Somewhere North of Dover, AR
    Here is a pic of me back in 1990. Flanked by my YZ490 and ATK406. I had just moved to the Ozark foothills in Arkansas and found out that YZ was only good for throwing rocks and the ATK was only good as conversation piece. :D

    I had sooooo much to learn, like how low can you mount a handlebar?

    [​IMG]
    #93
  14. mudmantra

    mudmantra Been here awhile

    Joined:
    Jul 6, 2009
    Oddometer:
    364
    Location:
    Humboldt
    A little catching up to do. I replaced the crankshaft seal. Rebuilt the clutch, with new springs, steel and friction plates. Installed new kick starter springs and washer. I also installed new washers on the kick starter idle gear. I had some worn parts, so I selected my best old spare parts and put it together. At first, the kick starter wouldn't engage right. So I checked it out and replaced the kick starter shaft, with another spare. Seemed to do the trick, because it works perfect now. I also installed a push button compression release. Mostly to reduce strain on the kicker parts. Some of them are no longer available. I think I have the jetting pretty good. This video show giving it a little throttle, then dethrottling once the front starts to come up. I'm already forward over the tank and not letting the RPM's climb. The goal is to keep the front end down and get a feel for it, before I take it to the woods. :D
    http://youtu.be/nDvy2THiefo
    #94
  15. mudmantra

    mudmantra Been here awhile

    Joined:
    Jul 6, 2009
    Oddometer:
    364
    Location:
    Humboldt
    On the YZ465, All I had done was the cylinder head mod and the cylinder bored out to 86.5mm. I thought I had the ports done too. But not on this one. I think the cylinder head mod and getting the jetting dialed in will cure the pinging. I had the porting done on the YZ490. I'm installing a compression release, then I'll get it running too.
    #95
  16. brucifer

    brucifer Long timer

    Joined:
    Nov 27, 2007
    Oddometer:
    3,316
    Location:
    Eureka, Ca.
    Nice, effortless wheelies. Sounds good too. :clap
    #96
  17. mudmantra

    mudmantra Been here awhile

    Joined:
    Jul 6, 2009
    Oddometer:
    364
    Location:
    Humboldt
    Nice bikes. :thumb Thanks for the jetting information. I don't know exactly where I've got mine jetted at, but it's running pretty good. It hasn't fouled a plug yet and it starts right up. Normally 2 or 3 kicks cold. Installing an IT crankshaft is something I've thought about too. Do you know how much more they weight over the YZ crankshaft? I just installed a 16 OZ. flywheel weight on my YZ465. It still rips, but I think it dose offer a little more throttle control. Another effect , I think it helps keep the motor rolling during starting. Plus it seems to idle better. I need to make a flywheel cover spacer, then I'll test it on the dirt.
    #97
  18. wfopete

    wfopete Suffer Fools; Gladly!

    Joined:
    Aug 19, 2004
    Oddometer:
    850
    Location:
    Somewhere North of Dover, AR
    I don't know about FW weight, but I bet FJ Kevin does! For myself the IT lower end advantages are more than FW weight. I like having a lower first gear, taller fifth and wider spacing between gears. Oh and a lighting coil.
    #98
  19. mudmantra

    mudmantra Been here awhile

    Joined:
    Jul 6, 2009
    Oddometer:
    364
    Location:
    Humboldt
    Yes a complete IT lower end, gears and all would be nice. I think the 5 speed on the yz465 well be fine for me. On the next rebuild on my YZ465, I'd like to install a IT465 crankshaft and my spare 1981 YZ465 cylinder. I'll just use the flywheel weight for now.
    #99
  20. mudmantra

    mudmantra Been here awhile

    Joined:
    Jul 6, 2009
    Oddometer:
    364
    Location:
    Humboldt
    Thanks. Even with the 16oz. flywheel weight it acts the same. It give you just a little extra warning before the front end comes up. I bought the flywheel weight for the YZ490, but I think the YZ465 needs it more. The 490 pulls the front end up easy in all gears, but has a more steady feel to it.