transmission jumped in gear from nuetral

[kwacker83]

  So I drive up to a lookout on my 92 kx500, I brought my step son riding(xr70) so my day involved a lot of nuetral sitting and revving to ease my fears of fouling a plug lugging all day. My bike sat for about 25 min. The hill down was rocky and I was waiting at bottom for him, I got a little rev happy this time cleaning it out and out of nowhere it jumps in gear and locks up after lunging forward a few feet. It fired with clutch pulled but died as soon as let out. I had to get towed back to truck holding clutch lever. The shifter moved up and down but would not click or find nuetral no matter how much I rocked it. The bike was shifting fine every ride till this.
 Upon getting home I filled the transmission up with wd40. The next day I rocked it enough and found nuetral. The shifter seemed slightly better as it clicked(but not a solid normal "click")first, nuetral, second, but stop trying to go into 3rd. At my friends shop we took off clutch cover and clutch and all springs appeared fine, he split the case for me and said all gears slide fine and nothing is chipped or broken. Everything looks clean.
 Sorry for long post I just want to be descriptive,  I have searched problem and was hoping it would be one of the springs behind clutch. Can anyone point me in a direction of where to look or check. Thanks
 

[Foxx4Beaver]

how do the shift forks look?...possibly could've bent one.
check the small spring on the gear change mechanism too...there's actually 2 springs in there...one is part #92081-076 which is a "return" spring , and the other is #92145-1368.

[Foxx4Beaver]

also, being a '92, there's a good chance most of that tranny is original...meaning there could be a lot of worn parts and contributing factors.
This was the case with mine a couple years ago...mine started jumping outa gear due to a broken snap ring...but once I pulled it apart, I found several worn gears, worn and bent forks, worn shift drum....so instead of just replacing a few things, I replaced the entire tranny and gear change mechanism, because I didn't want to mate any new parts to any old parts.
I really doubt you'll need to go to that extreme, but be sure to check everything really well....if you don't have a service manual, get one...as it'll give you all the wear tolerance specs on all the tranny parts.

[kwacker83]

  I am heading to the shop today to check things out myself. I know I need a service manual. Where is the best place to get one?I really would like an original book.
 
Can anyone give the specs to check on shift forks and drum?I am probably at a standstill till I can get the tolerances for gearbox.

 I have seen bikes that pop out of gear or miss a gear or just shift notchy but this is my first time having a bike that seemed fine jump out of nuetral then lock up and it not shifting into third. Thanks for the help.

One more question,  did Kawi not use a gasket on main case halves? This bike did not have one.

[Foxx4Beaver]

  I am heading to the shop today to check things out myself. I know I need a service manual. Where is the best place to get one?I really would like an original book.
 
Can anyone give the specs to check on shift forks and drum?I am probably at a standstill till I can get the tolerances for gearbox.

 I have seen bikes that pop out of gear or miss a gear or just shift notchy but this is my first time having a bike that seemed fine jump out of nuetral then lock up and it not shifting into third. Thanks for the help.

One more question,  did Kawi not use a gasket on main case halves? This bike did not have one.

you can find used and new manuals on e-bay all day long...'88-'04.

no gasket between the case halves...a good layer of Yamabond-4 or Threebond case sealer is the only thing used to seal it up.

[kwacker83]

 I don't know how I missed it before, but El Snorro had a link to a free FSM download here. I will let you know what I find later.

[Foxx4Beaver]

yeah I forget he posted that too sometimes...keep us posted.

[sandblaster]

SHIFT FORK AND SHIFT DRUM SPECIFICATIONS
Scroll down about half way down the page to find it.

http://www.oem-cycle.com/forum/viewtopic.php?f=49&t=344

[kwacker83]

 Well I lucked out some. Every tolerance in my transmission for gears, drum and forks(checked for straightess) was right at the tightest side of tolerances.  For a 92 it either was barely ridden(which is what I was told) or had everything new installed. I assembled everything in the case half and clicked through gears and rotated gears slow, in two positions(first and nuetral I assume) everything seemed fine. Clicking up through gears the forks slid sideways fine but I could only rotate the gears half way around before they bound up. I noticed the dogs were not engaging into one of the gears. I pulled both shafts out with gears together. Fifth gear was not spinning. I could barely turn it using all my force. I removed circlips on gears and they all slid off easy except this one needed to be tapped with a rubber mallet.
 So all I need is the gear, shaft and related gakets and seals for reassembly. I am going to replate cylinder and do top end.
 Thinking about how this could've happened to a tight gearbox that was shifting fine I believe when I had the bike parked resting it was leaned far to stator side on a rock.I rolled down the trail and popped bike near bottom (short distance) and was revving out bike. The bike was warmed up and I assumed was alright. I guess it takes a bit longer to get oil in parts than I thought from it being leaned over.
 For now on I will never rev a bike more than the small burp needed to keep it clean while sitting in nuetral.
 
Thanks for the help. I am glad there is still a lot of good info out there for this bike. I love this bike and plan to keep it in my family.

[Foxx4Beaver]

awesome, good to hear!....
since you're gonna have it replated and new top end...now's also the time to replace all the bearings and seals in the bottom end too while it's apart.

[reklessj]

awesome, good to hear!....
since you're gonna have it replated and new top end...now's also the time to replace all the bearings and seals in the bottom end too while it's apart.

Absolutely!!! No need tearing it apart again this year right?

[kwacker83]

 Yeah I know I should but this thing is tight. It is the least vibration of any big bore I have ridden, doesn't seem to bother me. You guys are right though and I should for peace of mind.

[DoldGuy]

Kwacker,

What fluid was in the crankcase? How did it look when you drained it?

DoldGuy

[reklessj]

Yeah I know I should but this thing is tight. It is the least vibration of any big bore I have ridden, doesn't seem to bother me. You guys are right though and I should for peace of mind.

Just do it man!!! Pretty cheap insurance, since ya already hAve her cracked open. Remember as you stated if it is just really low hrs bike those seals are 24 yrs old (ready to let loose any time)

[kwacker83]

Kwacker,

What fluid was in the crankcase? How did it look when you drained it?

DoldGuy

The bike had a gear lube type oil in it when I got it, it had a slight greyness in it, not milky and did not smell fuel. I replaced it with rotella.