ADVrider

Go Back   ADVrider > Bikes > Thumpers
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 01-13-2009, 04:52 PM   #31
dentvet
Beastly Adventurer
 
Joined: Aug 2008
Location: hunt country virginia
Oddometer: 1,194
bdc doesn't really matter. you just want the piston down to reveal the cylinder walls. I'm not sure you'll even be able to sight through the hole , depending on the sight-line etc, but i thought it was worth the suggestion. if you can see heavily scored areas on the cylinder, that would be good to know. Some mechanics have borescopes for such examinations. i have a medical endoscope that might work if you want to haul your bike over here. Or you could just pull the head off and looksee.
dentvet is offline   Reply With Quote
Old 01-13-2009, 04:54 PM   #32
cyclewizard
Beastly Adventurer
 
cyclewizard's Avatar
 
Joined: May 2007
Location: Norway/Michigan.
Oddometer: 4,797
The bad thing about the xl500 motors is the cam rides in plain bearing that are part of the head, you can't replace them.
When you run one of these motors out of oil or low on oil or with dirty oil it takes out the head.
Megacycle can machine your head and rocker box for needle bearings to fix a problem like this.

I would pull the rocker box and at least take a look at to see if they got damaged and then go from there. I would say the bearings probably aren't looking to good after that ordeal. 168.00 to machine the head for the NB cam.
http://www.megacyclecams.com/
__________________
C-dub......


Powered by CW-Pistons/cams
Wizard manufacturing....

cyclewizard screwed with this post 01-13-2009 at 05:09 PM
cyclewizard is offline   Reply With Quote
Old 01-13-2009, 05:16 PM   #33
mtn500 OP
bush jumper
 
mtn500's Avatar
 
Joined: Sep 2006
Location: Floyd, VA, Edenton, NC
Oddometer: 301
i tried looking down the spark plug hole and no dice. can't see too much of anything due to the angle with the engine sitting in the frame.

cyclewizard, thanks for the headsup about megacycle cams, they might be a useful option in the near future.

as for now, my next move will be to further examine the top end and see what damage i can find. finding the time to do it is going to be the hard part but i will keep everyone informed as to what i find.

i would still like to do a compression check, but that may be a mute point if i take the top end apart and find i need to have it reworked; if that is the case then she may as well have her first complete rebuild.

thanks for everyone's help and suggestions. i'm still open to any and all if you have them.
__________________
certs and destroy

If... the machine of government... is of such a nature that it requires you to be the agent of injustice to another, then, I say, break the law.

When any government, or any church for that matter, undertakes to say to its subjects, "This you may not read, this you may not see, this you are forbidden to know", the end result is tyranny and oppression no matter how holy the motives.


mtn500 is offline   Reply With Quote
Old 01-14-2009, 05:22 AM   #34
cyclewizard
Beastly Adventurer
 
cyclewizard's Avatar
 
Joined: May 2007
Location: Norway/Michigan.
Oddometer: 4,797
At least pull the rocker box off an look at the cam and bearings.
The cam might have seized in the head when it got hot from lack of oil.
It only takes a few minutes to do that.
__________________
C-dub......


Powered by CW-Pistons/cams
Wizard manufacturing....
cyclewizard is offline   Reply With Quote
Old 01-14-2009, 08:12 AM   #35
mtn500 OP
bush jumper
 
mtn500's Avatar
 
Joined: Sep 2006
Location: Floyd, VA, Edenton, NC
Oddometer: 301
Quote:
Originally Posted by cyclewizard
At least pull the rocker box off an look at the cam and bearings.
The cam might have seized in the head when it got hot from lack of oil.
It only takes a few minutes to do that.
actually, to pull anything off the topend besides the valve covers, the motor has to come out of the frame. i really wish it only took a few minutes and was that easy but it is a time consuming process--unless you know something about that motor in that frame that i don't ??


where ive drawn a red line around the top of the motor is where a cover is. is that the rocker box you write of? that cover requires a new gasket when it is removed (not a paper gasket, the type from a tube). this engine is notorious for leaking at that gasket, and mine did suffer from that leak but has been fixed. in order to take that cover off and apply new gasket, the engine has to come out of frame.
thanks
__________________
certs and destroy

If... the machine of government... is of such a nature that it requires you to be the agent of injustice to another, then, I say, break the law.

When any government, or any church for that matter, undertakes to say to its subjects, "This you may not read, this you may not see, this you are forbidden to know", the end result is tyranny and oppression no matter how holy the motives.



mtn500 screwed with this post 01-14-2009 at 08:31 AM
mtn500 is offline   Reply With Quote
Old 01-14-2009, 09:50 AM   #36
cyclewizard
Beastly Adventurer
 
cyclewizard's Avatar
 
Joined: May 2007
Location: Norway/Michigan.
Oddometer: 4,797
OK.......that's a little more than a few minutes, more like a few hours.
__________________
C-dub......


Powered by CW-Pistons/cams
Wizard manufacturing....
cyclewizard is offline   Reply With Quote
Old 01-14-2009, 10:25 AM   #37
JustinT
I will ride my whole life
 
JustinT's Avatar
 
Joined: Mar 2008
Location: The Great US
Oddometer: 943
Were you running it with open headers when it seized? No matter now have to fix it.

This is almost as severe as you can get on these air cooled thumpers without getting into the transmission.

What you felt when it was hard to kick over was a partially seized piston due to heat or lack of lubrication (doesn't matter at this point) but if you were able to move it at all with the kicker then it did score the cylinder wall some...This isn't your worry because the damage is done and it'll just have decreased compression.

Your worry is possible Lack of lubrication in the cam/rocker assembly which will cause premature wear.

ALSO

Lack of lubrication and wear in the small end of the rod which will fail if scored and roughened up as well.

So the search for the cause is needed for the repair anyway.

I'd say go ahead and pull the motor and plan on putting at least a piston and rings in it if everything is perfect because you will have it off to look at the small end of the rod anyway...(need to have the motor out anyway based on what you said)

But due to your description I suspect you will need piston/rings, cylinder honed minimum. but likely will need a rod and possible head work. (if its an old cam chain...replace it and the adjuster and gears while its apart)

It sounds like alot but if parts are available and similar to price with later XR's then it will be worth fixing it

So my point is...either pull it and check it out right...or if its not worth pulling it...ride it till its dead...then pull it, except for leaving you stranded if it fails the head work is the only thing that would be better to address sooner than later if it needs it

my 2 cents
__________________
Full Throttle - it either solves the problem or ends the suspense
JustinT is offline   Reply With Quote
Old 12-27-2011, 04:01 PM   #38
mtn500 OP
bush jumper
 
mtn500's Avatar
 
Joined: Sep 2006
Location: Floyd, VA, Edenton, NC
Oddometer: 301
well i certainly did not intend to take this long but after a short hiatus....i pulled the motor and removed the top end. what i saw was somewhat discomforting, but expected. check out the timing chain sprocket. it looks like the sprocket has ground into the edge of the cam journal.



my next move it to remove the head and see what other damage i might find.

any suggestions on the cam journal? anybody got a cylinder head for a 1979-1981 xl/xr500 collecting dust?
__________________
certs and destroy

If... the machine of government... is of such a nature that it requires you to be the agent of injustice to another, then, I say, break the law.

When any government, or any church for that matter, undertakes to say to its subjects, "This you may not read, this you may not see, this you are forbidden to know", the end result is tyranny and oppression no matter how holy the motives.


mtn500 is offline   Reply With Quote
Old 12-27-2011, 04:33 PM   #39
dorkpunch
Oops...
 
dorkpunch's Avatar
 
Joined: Aug 2006
Location: Blackfoot, ID
Oddometer: 4,941
Wow, thats a new one! Can't for the life of me figure out what would cause the came to slide sideways like that?! I'm almost willing to bet that this is your only problem... Unless aluminum filings have worn out a bunch of other stuff in the engine. If it was mine AND I didnt want to spend any money, I'd first figure out what caused the cam to shift sideways like that, then clean up the edges of that journal as best I could with a file or dremel or something, polish it all up, and stick it back together. If it was mine and I wanted to TRUST it ever again on long trips far from tools, then yes, you'd probably better find a new cam and head. STILL figure out why the cam is pushed over like that though- is the cam chain tensioner messed up? missing a shim? Loose bolts on the rocker box cover? Did the cam eat into the journal on one side causing it to be at an angle and rub like that? Soooo many questions...
__________________
http://www.mobilemrt.com http://www.dorkpunch.com

"I've been going to this high school for SEVEN YEARS. I'm no dummy!"
-Charles De Mar.
dorkpunch is offline   Reply With Quote
Old 12-27-2011, 05:40 PM   #40
NJ-Brett
Brett
 
Joined: Sep 2010
Location: Southern New Jersey
Oddometer: 6,104
That is what happens with lack of oil, all thrust loaded parts wear and melt.
Even the steel cam looks like it melted and wore away, unless that is melted head deposited on it.
Roller and ball bearings can go a long time without much oil, not so plain bearings, or no bearings.







Quote:
Originally Posted by dorkpunch View Post
Wow, thats a new one! Can't for the life of me figure out what would cause the came to slide sideways like that?! I'm almost willing to bet that this is your only problem... Unless aluminum filings have worn out a bunch of other stuff in the engine. If it was mine AND I didnt want to spend any money, I'd first figure out what caused the cam to shift sideways like that, then clean up the edges of that journal as best I could with a file or dremel or something, polish it all up, and stick it back together. If it was mine and I wanted to TRUST it ever again on long trips far from tools, then yes, you'd probably better find a new cam and head. STILL figure out why the cam is pushed over like that though- is the cam chain tensioner messed up? missing a shim? Loose bolts on the rocker box cover? Did the cam eat into the journal on one side causing it to be at an angle and rub like that? Soooo many questions...
NJ-Brett is offline   Reply With Quote
Old 01-02-2012, 10:42 AM   #41
GravvyTrain
Adventurer
 
Joined: Dec 2011
Location: Southeast US
Oddometer: 28
[QUOTE=mtn500;17601875]

I have an 82 xl500r, and just about the same kinda thing happened to me just last week. Motor seized- loss of power ,and the kicker won't move. Not too sure if it overheated, but it also had an exhaust leak and after I bought the bike I changed the oil and it had metal in it as well as a clicking-tapping noise when running... So far I have the motor dismounted but this is my first time doing engine work. How can I get top cover off like your picture? Do I have to pry on it with a crowbar ?

GravvyTrain is offline   Reply With Quote
Old 01-02-2012, 10:48 AM   #42
brucifer
Beastly Adventurer
 
brucifer's Avatar
 
Joined: Nov 2007
Location: Eureka, Ca.
Oddometer: 2,213
There's bolts under your valve inspection covers. DO NOT USE A CROWBAR!! Pull those covers and you'll see.
__________________
2005 KTM 525EXC-2000 Buell M2 Cyclone-1996 XR600R-Plated 1995 XR600R-1993 Kawasaki KX500-1984 Honda XL600R/XR650L Hybrid-1984 Yamaha TT600L-1980 Honda CB750F

XL600R Build http://advrider.com/forums/showthrea...4+xl600r+build For Sale
brucifer is offline   Reply With Quote
Old 01-02-2012, 11:48 AM   #43
mtn500 OP
bush jumper
 
mtn500's Avatar
 
Joined: Sep 2006
Location: Floyd, VA, Edenton, NC
Oddometer: 301
after the bolts from under the covers are out tap on the cylinder head cover in the solid spots with a rubber mallet to break the seal between the gasket and the head.
__________________
certs and destroy

If... the machine of government... is of such a nature that it requires you to be the agent of injustice to another, then, I say, break the law.

When any government, or any church for that matter, undertakes to say to its subjects, "This you may not read, this you may not see, this you are forbidden to know", the end result is tyranny and oppression no matter how holy the motives.


mtn500 is offline   Reply With Quote
Old 01-02-2012, 12:28 PM   #44
NJ-Brett
Brett
 
Joined: Sep 2010
Location: Southern New Jersey
Oddometer: 6,104
Please clean the motor off before taking it apart.
If by chance you get it doing again, you do not want all kinds of sand/dirt inside.

Maybe power wash it.
NJ-Brett is offline   Reply With Quote
Old 01-04-2012, 04:38 AM   #45
TnTiretracks
Adventurer
 
Joined: Jan 2011
Oddometer: 54
2 years and 3 months

Now, if I am looking at this right, it took mtn500 2 years and 3 months to fix his, if it is even fixed by now.
I hope that this never happens to me.
Hope that you finally got her running, you certainly have stayed with it.
TnTiretracks is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 01:27 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014