1981 YZ465 Won’t Run, Need Help

project racer 11/29/2018 3:24pm
11/29/2018 3:24pm
Put the bike in gear , hold the clutch in ,and rock it back and forth a number of times to try and break the plates free. I would do this with the engine not running , for your safety.

If that does not work, start the bike, push off a bit, and snick it in gear. Ride around with the clutch lever pulled in, tapping the rear break a bit, but not enough to stall it. This may also help free the clutch.
If the plates are stuck tight, disassembly and fibers are probably in the future.
wfoskir
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wfoskir 11/29/2018 7:38pm
11/29/2018 7:38pm
project racer wrote:
Put the bike in gear , hold the clutch in ,and rock it back and forth a number of times to try and break the plates...
Put the bike in gear , hold the clutch in ,and rock it back and forth a number of times to try and break the plates free. I would do this with the engine not running , for your safety.

If that does not work, start the bike, push off a bit, and snick it in gear. Ride around with the clutch lever pulled in, tapping the rear break a bit, but not enough to stall it. This may also help free the clutch.
If the plates are stuck tight, disassembly and fibers are probably in the future.
They are stuck tight. Once I got it running I did a rolling start to get going hoping it would break free as you mentioned. I rode it for about 5 minutes, no luck.
I will dig into this weekend when I have a bit more time.
riv187
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riv187 11/30/2018 6:25am
11/30/2018 6:25am
project racer wrote:
Put the bike in gear , hold the clutch in ,and rock it back and forth a number of times to try and break the plates...
Put the bike in gear , hold the clutch in ,and rock it back and forth a number of times to try and break the plates free. I would do this with the engine not running , for your safety.

If that does not work, start the bike, push off a bit, and snick it in gear. Ride around with the clutch lever pulled in, tapping the rear break a bit, but not enough to stall it. This may also help free the clutch.
If the plates are stuck tight, disassembly and fibers are probably in the future.
wfoskir wrote:
They are stuck tight. Once I got it running I did a rolling start to get going hoping it would break free as you mentioned. I...
They are stuck tight. Once I got it running I did a rolling start to get going hoping it would break free as you mentioned. I rode it for about 5 minutes, no luck.
I will dig into this weekend when I have a bit more time.
I have never failed to free a stuck clutch with the above way of riding with clutch pulled in zapping gas. I can also suggest switching to ATF +4.Any brand car quest,castrol ect.. It's thin and synthetic
and has made my old clutches smoother and less stick prone. Another tequnique I heard was tie the clutch lever in and let the bike sit over night.
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wfoskir 12/8/2018 3:02pm
12/8/2018 3:02pm
Today I rode the bike around for about five minutes, shifting gears, coasting with clutch in, hitting the brakes, holding the clutch, raving, hitting the brakes. It never would completely disengage. At times if felt like it would, then NO.
I drained the oil. Looked like oil out of an old bike, some metallic. Pulled the cover, pulled the plates, measured the plates and the springs. Oh, before I pulled the plates, I pulled the lever in and out and watched the pressure plate move in and out. All the plates measured almost new, steel plates look great, clutch springs are in spec. Cleaned everything, oiled the back up, installed them, put oil it and test road. SAME. Clutch has proper free play.
What am I missing?

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450exc115
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450exc115 12/8/2018 5:43pm
12/8/2018 5:43pm
Switch to ATF. Non dextron. Or a thinnest oil you can find
barnett468
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barnett468 12/8/2018 5:57pm
12/8/2018 5:57pm
wfoskir wrote:
Today I rode the bike around for about five minutes, shifting gears, coasting with clutch in, hitting the brakes, holding the clutch, raving, hitting the brakes...
Today I rode the bike around for about five minutes, shifting gears, coasting with clutch in, hitting the brakes, holding the clutch, raving, hitting the brakes. It never would completely disengage. At times if felt like it would, then NO.
I drained the oil. Looked like oil out of an old bike, some metallic. Pulled the cover, pulled the plates, measured the plates and the springs. Oh, before I pulled the plates, I pulled the lever in and out and watched the pressure plate move in and out. All the plates measured almost new, steel plates look great, clutch springs are in spec. Cleaned everything, oiled the back up, installed them, put oil it and test road. SAME. Clutch has proper free play.
What am I missing?
Exactly what happens after you start the bike then pull the clutch lever in then put it in gear?

What oil did you put in it?

look at the clutch release lever on the engine to see if someone lengthened it.

Remove all the freeplay and try it again.

wfoskir
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wfoskir 12/8/2018 8:52pm
12/8/2018 8:52pm
wfoskir wrote:
Today I rode the bike around for about five minutes, shifting gears, coasting with clutch in, hitting the brakes, holding the clutch, raving, hitting the brakes...
Today I rode the bike around for about five minutes, shifting gears, coasting with clutch in, hitting the brakes, holding the clutch, raving, hitting the brakes. It never would completely disengage. At times if felt like it would, then NO.
I drained the oil. Looked like oil out of an old bike, some metallic. Pulled the cover, pulled the plates, measured the plates and the springs. Oh, before I pulled the plates, I pulled the lever in and out and watched the pressure plate move in and out. All the plates measured almost new, steel plates look great, clutch springs are in spec. Cleaned everything, oiled the back up, installed them, put oil it and test road. SAME. Clutch has proper free play.
What am I missing?
barnett468 wrote:
Exactly what happens after you start the bike then pull the clutch lever in then put it in gear? What oil did you put in it...
Exactly what happens after you start the bike then pull the clutch lever in then put it in gear?

What oil did you put in it?

look at the clutch release lever on the engine to see if someone lengthened it.

Remove all the freeplay and try it again.

Bike running, pull in clutch, put it in gear and the bike takes off or dies from trying to take off.

I have always uses regular motor oil, 10W30. Clutch worked fine before the ignition system went hay wire.

Clutch release lever is stock

I will give it a try.
project racer 12/9/2018 3:04am
12/9/2018 3:04am
Clutch drag. Older Yamaha's are notorious for that. Basically, the plates are not being separated far enough when the lever is pulled in to disengage the plates. Check the condition of the clutch rod and ball.
wfoskir
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wfoskir 12/9/2018 6:17am
12/9/2018 6:17am
project racer wrote:
Clutch drag. Older Yamaha's are notorious for that. Basically, the plates are not being separated far enough when the lever is pulled in to disengage the...
Clutch drag. Older Yamaha's are notorious for that. Basically, the plates are not being separated far enough when the lever is pulled in to disengage the plates. Check the condition of the clutch rod and ball.
I will check this.
riv187
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riv187 12/9/2018 6:51am
12/9/2018 6:51am
I have a 1980 Y125. The clutch plates are probably from same fiber. Mine will drag and plates stick if it sits 1 week if I use motor oil. I switched to dextron atf+4 and 90% solved and only if it sits 6 months may it stick initially. If you don't getit going with oil change and have to take apart...look for burn marks on steels,,,indicating warpage that can cause drag. Lay plates on glass and look for warp or cupping.
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Hasletjoe 12/9/2018 2:44pm
12/9/2018 2:44pm
So if you have the clutch plates out, with the bike in gear, kick the bike over and see if the both inner and outer baskets are spinning with no clutch plates. I believe the outer basket should spin, but the inner will not. If the bike tries to move forward as if in gear, there is a problem with the assembly. My guess is a spacer if out of position or missing.
wfoskir
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wfoskir 12/9/2018 6:13pm
12/9/2018 6:13pm
riv187 wrote:
I have a 1980 Y125. The clutch plates are probably from same fiber. Mine will drag and plates stick if it sits 1 week if I...
I have a 1980 Y125. The clutch plates are probably from same fiber. Mine will drag and plates stick if it sits 1 week if I use motor oil. I switched to dextron atf+4 and 90% solved and only if it sits 6 months may it stick initially. If you don't getit going with oil change and have to take apart...look for burn marks on steels,,,indicating warpage that can cause drag. Lay plates on glass and look for warp or cupping.
If I take them out again, I will check them. I did inspect them when I had them out yesterday and they are all clean, not burn marks, look like new.
wfoskir
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wfoskir 12/9/2018 6:15pm
12/9/2018 6:15pm
riv187 wrote:
I have a 1980 Y125. The clutch plates are probably from same fiber. Mine will drag and plates stick if it sits 1 week if I...
I have a 1980 Y125. The clutch plates are probably from same fiber. Mine will drag and plates stick if it sits 1 week if I use motor oil. I switched to dextron atf+4 and 90% solved and only if it sits 6 months may it stick initially. If you don't getit going with oil change and have to take apart...look for burn marks on steels,,,indicating warpage that can cause drag. Lay plates on glass and look for warp or cupping.
This would be the easiest thing to try first.
wfoskir
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wfoskir 1/20/2019 8:57am
1/20/2019 8:57am
Went to the track yesterday in hopes to ride the 465 and 125 but it was a bit wetter than I was hoping. Didn’t figure would ride them. Then my FC350 decided not to cooperate so, the 465 it was. The clutch still has issues and you have to warm it up to drain the oil, so you may as well ride it! It has been many years since I rode that bike on a track, it was fun. I will see if I can’t get that clutch fixed today.

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sandman768 1/20/2019 2:47pm
1/20/2019 2:47pm
A worn/ notched basket will cause drag issues. Next time you have the clutch cover off, pull the actuation arm out of the case, and pull the push rod & ball bearing that push on the pressure plate top hat, when these become worn, it will cause drag issues...sometimes you can clean up the ends of the rod & arm, but severe wear requires replacement. 1mm of wear can cause drag, these clutches were not great to begin with...I"m rebuilding a 1981 yz250 for a friend, the clutch hard parts are pretty worn, The plates were stuck together pretty hard from sitting, metal plates rusted...if it were mine, I would buy whatever I could new Oem , but my friend is cheap so, we going to try & save/& repair what we can.
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barnett468 1/20/2019 4:36pm
1/20/2019 4:36pm
wfoskir wrote:
Went to the track yesterday in hopes to ride the 465 and 125 but it was a bit wetter than I was hoping. Didn’t figure would...
Went to the track yesterday in hopes to ride the 465 and 125 but it was a bit wetter than I was hoping. Didn’t figure would ride them. Then my FC350 decided not to cooperate so, the 465 it was. The clutch still has issues and you have to warm it up to drain the oil, so you may as well ride it! It has been many years since I rode that bike on a track, it was fun. I will see if I can’t get that clutch fixed today.

xlnt, glad it ran for you a least. i just bough an 80 and 81 yz465. i'm building one now for vintage mx.

.
wfoskir
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wfoskir 1/20/2019 6:53pm
1/20/2019 6:53pm
sandman768 wrote:
A worn/ notched basket will cause drag issues. Next time you have the clutch cover off, pull the actuation arm out of the case, and pull...
A worn/ notched basket will cause drag issues. Next time you have the clutch cover off, pull the actuation arm out of the case, and pull the push rod & ball bearing that push on the pressure plate top hat, when these become worn, it will cause drag issues...sometimes you can clean up the ends of the rod & arm, but severe wear requires replacement. 1mm of wear can cause drag, these clutches were not great to begin with...I"m rebuilding a 1981 yz250 for a friend, the clutch hard parts are pretty worn, The plates were stuck together pretty hard from sitting, metal plates rusted...if it were mine, I would buy whatever I could new Oem , but my friend is cheap so, we going to try & save/& repair what we can.
Basket, push rod and plates all look good and in tolerance.
The pic isn’t the best view but you can see the fiber plates fit good on the basket. I put ATF in this time, hopefully that does the trick.
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wfoskir 1/20/2019 6:59pm
1/20/2019 6:59pm
wfoskir wrote:
Went to the track yesterday in hopes to ride the 465 and 125 but it was a bit wetter than I was hoping. Didn’t figure would...
Went to the track yesterday in hopes to ride the 465 and 125 but it was a bit wetter than I was hoping. Didn’t figure would ride them. Then my FC350 decided not to cooperate so, the 465 it was. The clutch still has issues and you have to warm it up to drain the oil, so you may as well ride it! It has been many years since I rode that bike on a track, it was fun. I will see if I can’t get that clutch fixed today.

barnett468 wrote:
xlnt, glad it ran for you a least. i just bough an 80 and 81 yz465. i'm building one now for vintage mx.

.
Yea, I have been to this track twice now and each time I have had a bike issues. Not a good average! Good thing I bring more than one bike.
Good luck on your build.

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barnett468
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barnett468 1/20/2019 7:47pm
1/20/2019 7:47pm Edited Date/Time 1/20/2019 7:50pm
wfoskir wrote:
Went to the track yesterday in hopes to ride the 465 and 125 but it was a bit wetter than I was hoping. Didn’t figure would...
Went to the track yesterday in hopes to ride the 465 and 125 but it was a bit wetter than I was hoping. Didn’t figure would ride them. Then my FC350 decided not to cooperate so, the 465 it was. The clutch still has issues and you have to warm it up to drain the oil, so you may as well ride it! It has been many years since I rode that bike on a track, it was fun. I will see if I can’t get that clutch fixed today.

barnett468 wrote:
xlnt, glad it ran for you a least. i just bough an 80 and 81 yz465. i'm building one now for vintage mx.

.
wfoskir wrote:
Yea, I have been to this track twice now and each time I have had a bike issues. Not a good average! Good thing I bring...
Yea, I have been to this track twice now and each time I have had a bike issues. Not a good average! Good thing I bring more than one bike.
Good luck on your build.
thanks, i am basically just replacing a few worn parts then trying it in vintage racing. if it is too much for me then at least i won't have a bazillion dollars in it which should make it easier to sell. i am currently racing an fmf modified 1980 yz250 at the local vintage races in the 250 class and occasionally in the open class, but it is a little hard to keep up with some of the big bores in the open class.

.
also, if your fork boots are not stock, you should remove the spring from a fork then collapse it and see if the boot is preventing your forks from compression all the way if you haven't done this already.

.
wfoskir
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wfoskir 1/21/2019 8:34pm
1/21/2019 8:34pm
barnett468 wrote:
xlnt, glad it ran for you a least. i just bough an 80 and 81 yz465. i'm building one now for vintage mx.

.
wfoskir wrote:
Yea, I have been to this track twice now and each time I have had a bike issues. Not a good average! Good thing I bring...
Yea, I have been to this track twice now and each time I have had a bike issues. Not a good average! Good thing I bring more than one bike.
Good luck on your build.
barnett468 wrote:
thanks, i am basically just replacing a few worn parts then trying it in vintage racing. if it is too much for me then at least...
thanks, i am basically just replacing a few worn parts then trying it in vintage racing. if it is too much for me then at least i won't have a bazillion dollars in it which should make it easier to sell. i am currently racing an fmf modified 1980 yz250 at the local vintage races in the 250 class and occasionally in the open class, but it is a little hard to keep up with some of the big bores in the open class.

.
also, if your fork boots are not stock, you should remove the spring from a fork then collapse it and see if the boot is preventing your forks from compression all the way if you haven't done this already.

.
My 465 is completely original, it is a survivor. I believe it to be a low hour machine. All original plastic with the #1 behind the current background, original seat, exhaust,... It has been a solid bike for me until lately, but I will get it back to 100%. I also have a 250 that is original as well, but I have made a few mods to it (still have the original parts though), 465 swing arm Longer) 465 front brake, gold wheels (its a 1980)... The bikes are in my avatar
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barnett468 1/21/2019 9:13pm
1/21/2019 9:13pm
wfoskir wrote:
Yea, I have been to this track twice now and each time I have had a bike issues. Not a good average! Good thing I bring...
Yea, I have been to this track twice now and each time I have had a bike issues. Not a good average! Good thing I bring more than one bike.
Good luck on your build.
barnett468 wrote:
thanks, i am basically just replacing a few worn parts then trying it in vintage racing. if it is too much for me then at least...
thanks, i am basically just replacing a few worn parts then trying it in vintage racing. if it is too much for me then at least i won't have a bazillion dollars in it which should make it easier to sell. i am currently racing an fmf modified 1980 yz250 at the local vintage races in the 250 class and occasionally in the open class, but it is a little hard to keep up with some of the big bores in the open class.

.
also, if your fork boots are not stock, you should remove the spring from a fork then collapse it and see if the boot is preventing your forks from compression all the way if you haven't done this already.

.
wfoskir wrote:
My 465 is completely original, it is a survivor. I believe it to be a low hour machine. All original plastic with the #1 behind the...
My 465 is completely original, it is a survivor. I believe it to be a low hour machine. All original plastic with the #1 behind the current background, original seat, exhaust,... It has been a solid bike for me until lately, but I will get it back to 100%. I also have a 250 that is original as well, but I have made a few mods to it (still have the original parts though), 465 swing arm Longer) 465 front brake, gold wheels (its a 1980)... The bikes are in my avatar
very cool. i have an 80 yz250 also that i have been vintage racing. it was ported by fmf back in the day.

i bought a 465 swingarm for mine and should have it installed tomorrow and will try it out at a vintage race this sunday.

just curious, did you notice much difference in your 250 after you installed the longer arm. it should have made it slightly harder to turn.

..
Hasletjoe
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Hasletjoe 1/23/2019 10:35am
1/23/2019 10:35am
Time for a bit of humor....... humor.......

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