1982 yz 490 still having clutch problems

[JPbigbore]

Hey guys I have an 82 yz490 and I finally got the kickstart that was holding me back on a complete restore, but I'm still having problems with the clutch. I can't get it to come free. Here's what I've tried: I've pulled the entire clutch pack apart and made sure the plates weren't stuck together, I put it back together making sure all the plates were in the same order they came out, the push rod is in place with the ball bearing, the springs on the pressure plate are to the right torque. The adjuster on the pressure plate is in place, I. Adjusted it so that the projection on the case lines up with the clutch are amd I have the lever adjusted right and still nothing. After starting the bike I warm up the clutch real good, and with my foot on the brake I drop it into gear and it dies instantly.?? I'm open to suggestions. Any and all help will be greatly appreciated. Thanks

[motoxvet]

You say you put the plates back in the same way they came out. Are you sure they were installed correctly in the first place? If you don't have any kind of service manual, check one of the parts supplier web sites on the net that sells OEM parts. They show a blow-up with correct count and locations of the plates. It's a shame to not be able to ride an awsome bike like that! Good luck on the fix.

[SMarquez]

Do you have the correct cable on it? Is it new? Stock or aftermarket? How much of the adjuster at the lever have you used? If you adjusted most of the slack out of the cable you may not have enough pull left in the cable. Is the adjuster in the center of the clutch adjusted to make contact with the clutch rod? Do you have an old cable to try on it or compare? Are you sure you don't have 1 too many plates in there?

Good luck.

[JPbigbore]

You say you put the plates back in the same way they came out. Are you sure they were installed correctly in the first place? If you don't have any kind of service manual, check one of the parts supplier web sites on the net that sells OEM parts. They show a blow-up with correct count and locations of the plates. It's a shame to not be able to ride an awsome bike like that! Good luck on the fix.

I have a yamaha service manual for it, the plates are in the way they should be, the only thing I wonder is if they've ever been taken out and been mixed up. A friend of mine had the bike before me and had the clutch pack apart to put a new kickstart gear in. Maybe he mixed up the order when he put it back together?

Do you have the correct cable on it? Is it new? Stock or aftermarket? How much of the adjuster at the lever have you used? If you adjus.ted most of the slack out of the cable you may not have enough pull left in the cable. Is the adjuster in the center of the clutch adjusted to make contact with the clutch rod? Do you have an old cable to try on it or compare? Are you sure you don't have 1 too many plates in there?

Good luck.

This is the cable that has always been on the bike, it worked before my friend had the clutch pack apart. The adjuster on the pressure plate is tightened until there's resitance, so it should be making contact with the rod. I have a pretty good amount of adjustment left at the lever not a whole lot but a bit. I don't have any old cables at hand but that's a good idea, I'll get some and try it. I'm going to take the clutch apart again today and double check everything, hopefully I can come up with something. Thanks again guys.

[johnnyboy]

I know you didnt but someone else may have overfilled the gear oil lol

[funke5372]

wait if you over fill the gear oil what does that do make not enough friction for the plates to connect?

[JPbigbore]

I know you didnt but someone else may have overfilled the gear oil lol

Would that ruin the plates for life? Because I've had the clutch cover off and the clutch pack. Apart a number of times. I've always filled it to spec. I'm starting to think new clutch plates are in the near future.?

[scalejockey]

Check the proper thickness and amount thrust washers of the basket and if the bearing for the shaft has no side play.

Sometimes it's the drag of the side washers\thrust.

Look for evidence of burnt\worn washers..

Edited December 3, 2011 by scalejockey

[SMarquez]

Check the proper thickness and amount thrust washers of the basket and if the bearing for the shaft has no side play.

Sometimes it's the drag of the side washers\thrust.

Good call there. Maybe get away from it for a day or two to refresh your perspective. Maybe something will jump out at you with a clear head.

[JPbigbore]

Check the proper thickness and amount thrust washers of the basket and if the bearing for the shaft has no side play.

Sometimes it's the drag of the side washers\thrust.

Look for evidence of burnt\worn washers..

I had never thought of that, thanks I'll look into that.

Good call there. Maybe get away from it for a day or two to refresh your perspective. Maybe something will jump out at you with a clear head.

That's a good point, after messing with for so long with no result a guy kind of starts to get frusturated. Thanks

[txsbuckeye490]

friction plate first then alternate & should be friction plate last...leave cover off and pull on lever & watch to see if clutch pack moves when you pull on lever you could have too many plates...the picture in my clymer manual was different than the picture on a yamaha dealers parts picture...just my 2cnts Rick (i have an 82 also & i love it!!)

[JPbigbore]

friction plate first then alternate & should be friction plate last...leave cover off and pull on lever & watch to see if clutch pack moves when you pull on lever you could have too many plates...the picture in my clymer manual was different than the picture on a yamaha dealers parts picture...just my 2cnts Rick (i have an 82 also & i love it!!)

How many plates is there supposed to be? How many friction? How many steel? With the cover off I can pull the lever and watch the plates move the plates move.. I wish I could enjoy mine like you do yours? these bikes are real monsters ?

[txsbuckeye490]

dealer pic shows 7 friction & 6 steel...beast from the east is what i call mine...i here alot of bad talk about the 490 engine but if you do the mod to the head it lowers the compression & that helps a bunch...if i can get the money together my jug & head is going to Eric Gorr's Forward Motion ...he & Rich Rohrich have had a ton of dealings with the 490 & know what to do to them to make "run" better if ya know what i mean Rick

[JPbigbore]

dealer pic shows 7 friction & 6 steel...beast from the east is what i call mine...i here alot of bad talk about the 490 engine but if you do the mod to the head it lowers the compression & that helps a bunch...if i can get the money together my jug & head is going to Eric Gorr's Forward Motion ...he & Rich Rohrich have had a ton of dealings with the 490 & know what to do to them to make "run" better if ya know what i mean Rick

I've got 7 friction and 6 steel plates starting and ending with. A friction. That's what my yamaha service manual shows also. I haven't hear the best of things about the 490's either, its basically a hopped up 465, the bottom ends are identical. I'm not sure if mine has the head mod done or not, but its got all matching numbers and still running on a standard bore, and judging from the condition it was in when I got it I'm guessing it was rode hard and put away wet most of its life, so I'm not sure if its had the head shaved or not, would you be able to tell just by looking at it? And I don't know what they look like stock but my cylinder is ported up the ass.

[JPbigbore]

Check the proper thickness and amount thrust washers of the basket and if the bearing for the shaft has no side play.

Sometimes it's the drag of the side washers\thrust.

Look for evidence of burnt\worn washers..

Can you explain these thrust washers better for me? I'm not sure I fully understand what you mean. Thanks

[scalejockey]

Can you explain these thrust washers better for me? I'm not sure I fully understand what you mean. Thanks

# 13 ,14 ,15.These can sometimes be worn,thus adding friction to the normally free spinning basket.

http://www.yamaha-motor.com/partviewer/default.aspx?ls=sport#/Yamaha/YZ490J_-_1982/CLUTCH/YZ490J_(1982_MOTORCYCLE)/CLUTCH_(YZ490J_-_1982)

[txsbuckeye490]

if you look at the exploded picture of the clutch assy there is a thrust washer on the front of the basket & one behind the basket , there also is a "

spacer" on the shaft the the basket rides on check all of those for signs of binding also check the primary drive gear rivets that hold the gear to the back of the basket, when you have the clutch all back together & be fore you put the cover on put it in 3rd gear pull in the clutch lever & get someone to try & turn the back wheel by hand (take out the spark plug) the wheel should move along with the clutch assy if it doesn't then maybe you can see what's going on...the head mod is not "shaving" but reshapeing the squish band it's hard to explain but i know there is a picture of the mod on another website somewhere ..i think it was on dirtrider.net ...as far as i know mine is all stock exept for the squish mod & i did that with a dremmel (guess i got lucky) cause it still will rip your arms off & that is the one & only time i've had the head off,i should have measured the bore but didn't..my bad cause i would like to get a topend for it to have before they get anymore hard to find or expensive

[JPbigbore]

# 13 ,14 ,15.These can sometimes be worn,thus adding friction to the normally free spinning basket.

http://www.yamaha-motor.com/partviewer/default.aspx?ls=sport#/Yamaha/YZ490J_-_1982/CLUTCH/YZ490J_(1982_MOTORCYCLE)/CLUTCH_(YZ490J_-_1982)

if you look at the exploded picture of the clutch assy there is a thrust washer on the front of the basket & one behind the basket , there also is a "

spacer" on the shaft the the basket rides on check all of those for signs of binding also check the primary drive gear rivets that hold the gear to the back of the basket, when you have the clutch all back together & be fore you put the cover on put it in 3rd gear pull in the clutch lever & get someone to try & turn the back wheel by hand (take out the spark plug) the wheel should move along with the clutch assy if it doesn't then maybe you can see what's going on...the head mod is not "shaving" but reshapeing the squish band it's hard to explain but i know there is a picture of the mod on another website somewhere ..i think it was on dirtrider.net ...as far as i know mine is all stock exept for the squish mod & i did that with a dremmel (guess i got lucky) cause it still will rip your arms off & that is the one & only time i've had the head off,i should have measured the bore but didn't..my bad cause i would like to get a topend for it to have before they get anymore hard to find or expensive

Oh I gotcha, thats what I thought they were I just wasn't totally sure, they seem to be in good shape and working condition, I'll try like you said after I get it back together.

[duner96]

is your basket notched?

[txsbuckeye490]

check the basket for notches like duner said also check the metal tabs on the friction plates you can "bevel" the edges of them with a flat jewelers file not much just take the "sharp" edges off them you can file any notches out of the basket to get a little more life out of it but if it is notched too bad you need to start looking for a replacement one...while you have someone to spin the back wheel try shifting through all the gears up & down