KX Riders
Maintenance & Technical => KX500 Original => Topic started by: MeanGreenMachine on August 16, 2013, 02:09:13 PM
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I recently got a 1990 KX500, and after riding the bike just enough to fall in love with it, I'm finding out that the previous owner was not all that honest about it's condition.
Things I've found so far:
- Water in transmission, milky oil: I found that the water pump seal was bad, and in fact, had silicone over a crack in it... Minimal shaft play, unable to feel any groove in the shaft with a screwdriver or a fingernail, so I just replaced the seal. Milkiness returned once, but it'll probably take another change or two before I know if it's gone for sure.
- Frame crack at the top near motor mount: Ground/notched, MIG welded and painted over. Seems to be holding fine.
- Stripped out drain plug: It came with a cut off 1/2-13 bolt in it, which then stripped. I made a guide jig and put a Perma-Coil in it to bring it back to 1/2-20. Then I installed a Fumoto F101 drain valve with about 1mm of metal "wall" left. It seems like it'll hold, though I don't exactly want to torque it too hard. The valve is well constructed and protected by my skid plate, so it should be safe. Should make changing oil easy, anyways.
So ok, it looks like I got it under control. I come home today and check the bike over in preparation for some badly needed riding time tomorrow and discover:
- Oil leaking from output shaft/chain sprocket: Must be a seal, unsure if installed from the outside or inside.
- Whirring noise at idle: Sounds suspiciously like the kind of noise a roller bearing makes when it's worn out. I pull the stator cover off and push/pull on the crank and notice that it wiggles up and down and side to side very, very slightly, though you can feel it and hear it tick when it moves. Also, the crank has some end play as well, when pushed or pulled directly. I turn the flywheel with my hand and notice that there's a very slight slack before the piston/rod move as well... Looks like I need a full rebuild. d**n it!
So, it looks like I won't be making it to Pismo after all. Further more it looks like I'll be sitting out on riding season trying to get this thing put back together. Does anybody have any ballpark estimates on how much I'm looking at to go through the entire engine, bottom end and top end rebuild, with crank, rod and new piston? Even though I got the bike for cheap and have become completely addicted to it, I could use some encouragement... I'd appreciate any information!
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The good thing and the bad thing about a K5 is that they can run a long time completely worn out if your not too hard on them but yours sounds like it is really in need.
At a minimum.... a crank rebuild, top end plating and piston, bearings, and seals, your looking a 1K minimum and of course, that's doing the work yourself and the sky's the limit on cost.
If you find out that 3rd gear is bad which is common, there's a couple of hundred more, if the exhaust valves are worn out, there's a few hundred more, ect, ect..
You really won't know until you get into it.
If I were you I would read this build..
http://www.kxriders.com/forums/index.php/topic,8717.0.html (http://www.kxriders.com/forums/index.php/topic,8717.0.html)
And
http://www.hallbergs.net/kx500/ (http://www.hallbergs.net/kx500/)
And
http://www.kxriders.com/forums/index.php/topic,8890.0.html
Of course, this is the right site for K5 info and rider sympathy :lol:
Oh.... save a few bucks and buy a Clymer Service manual...
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Yeah, I figure that my biggest problem right now is the crank mains and the rod bearings. It's funny since I compression tested it and ice cold, I was getting ~145 PSI, and looking through the exhaust port, the bore looked undamaged and KIPS valves moved freely. Obviously if I go through the bottom end, I'll send the top end for plating and get a new piston as well.
The pisser is that we were supposed to go to Pismo in two weeks... There's no way I can get parts out and back in time to have it ready. The guys are hounding me to "just ride it till it breaks", which IMO is probably a great way to end up with 10 times the damage and parts costs.
So what places do you guys recommend for plating? Millennium? US Chrome? Powerseal? What about crank rebuilding? I read about a place called Crank Works, but could use some recommendations. Probably time to start planning...
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K5's are notorious for wallering out the left main bearing journal on the case.
The more you ride it loose, the greater the chance of damage.
Also, if you ride it enough with a loose piston, the greater chance of breaking off a piston skirt and munching a set of cases...
But hey, new cases are available for about 450 bucks :-o
For a crank rebuild I would sent it out to Pinsonnault Racing for a rebuild, weld, true, and balance.
http://pinsonnaultracing.com/ (http://pinsonnaultracing.com/)
Your engine and hands will thank you from the reduction in vibration.
Plating?
I'll let other chime in...
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US Chrome +1
Jug came back beautiful within .0002 , the finish was sweet, sealed up quick
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Alright guys, aside from starting the day breaking off the kickstart lever :roll: (how much stronger is the improved part? Guess it's time for one), I bit the bullet and tore down the bike today. I've never taken a bike apart, but there didn't seem to be much to it. No unpleasant surprises so far, everything looks ok.
I currently have the engine out sitting on the bench and will start taking it apart tomorrow. The top end seems fairly straight forward. As for splitting the case halves, do you need a puller tool, or is there another way if your kx-fu is good enough? If the main bearing journals in the case are pounded/spun out, can the case be saved or is it time for new parts?
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There is all sorts of ways to split your cases...
I do it this way...
http://www.oem-cycle.com/forum/viewtopic.php?f=40&t=66 (http://www.oem-cycle.com/forum/viewtopic.php?f=40&t=66)
The newer kick lever design is stronger...
Get it apart and measure the bearing journals in the cases and tell us the measurements.... Then we can give you options :-)
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leakdown test before you take appart.
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Ok guys. As I expected, the top end came apart without any problems. The piston is an "ART" piece, size "A" that showed some light scratches but no apparent problems. There was no chamfer on any of the ports... Could the plating be stock?
The jug appears to be in good shape, but has a small area of flaking coating and 2 fine cracks between the main exhaust port and the 2 small KIPS booster ports on each side... The plating guys can weld these before plating, right? The KIPS parts have some carbon buildup but moved freely. There's a little bit of gear wear but it doesn't seem like it will effect much.
The rod has some slight movement on the big end if you pull up and down on it, but also rocks and slides side to side noticeably. That's probably part of the bearing noise I was hearing at idle. I haven't been able to split the case yet, but the crank has noticeable play on the clutch side bearing, which I guess makes sense since that's where power is taken off the crank.
Somewhere along the way I found another problem that concerns me - the splines on the output shaft that the chain sprocket goes on is very badly worn... I missed it until now. Do I have to replace the entire shaft/gears to fix it? Honestly, at this point, I'm afraid to split the cases and see what's inside, as it's clear that every part on this bike is worn completely out...
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Ok guys, I've made some progress today. I bought a couple 75mm long M6x1.0 bolts with the idea of screwing them into the stator holes, and using one of those crows foot shaped harmonic balancer pullers I had laying around. Problem was that the bolts were too short and the 2 opposing slots in the puller weren't long enough. I ended up cutting the head of the M6 bolts then threading them to make a stud. Then I put a 3/8x24 bolt on the lathe, drilled a hole into the end and tapped to accept the stud. Or you could just buy longer bolts, but I was bored at work. Then I went to Autozone and for $15 bucks picked up this: http://www.autozone.com/autozone/accessories/OEM-Timing-gear-and-pulley-puller/_/N-26b8?itemIdentifier=231208&_requestid=1684868
I used an open end wrench and carefully applied pressure, and sure enough, the cases popped right open, no problem. Try this at your own risk: I can't guarantee that 2 bolts will be strong enough, or won't strip the threads out of your cases or even break them. Use common sense and be careful!
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Honestly, I was dreading what I'd find inside to the point of dragging my feet, but it appears that everything looks pretty good so far. All transmission components appears to be in good working order (except that output shaft splines - I'll need to replace the shaft).
The output side crank main where the looseness was most noticeable doesn't look catastrophically failed. The core moves a little bit when prodded with a screwdriver and it's a little noisy when turned by hand, but thankfully the OD of the bearing appears firmly pressed into it's bore in the case. There's even a cast in iron sleeve that it rides in, which is a reassuring touch, especially with the mighty 500. I think that the problem is the crank journal - it slipped out of the bearing without any resistance, and the journal surface looks a little chudded, like it's been rolling/spinning a little. Will most crank rebuilders be able to spray/weld/sleeve/chrome and grind this back to spec?
I will need to investigate the engine and transmission innards in detail before I know for sure, but so far the damage tally is:
Topend:
- Possibly stock, 23 year old bore needs a replate.
- Cracks between KIPS booster ports and central port
- Pin shaped extension on one KIPS drum valve broken off, but seems to be holding the valve in place anyways
- Exhaust spring mount worn completely through in one place
Bottom end:
- Rod/bearings worn out
- Output side crank main bearing worn out, corresponding crank journal worn
- Transmission output shaft/sprocket splines damaged
- Kick start idler gear bushing wallered out
External
- Needs new fuel tank
- Kick starter broken
- Need to investigate rims/spokes for tension/true
- Front pipe mount broken off next to engine
- Threaded insert for side plastic missing in subframe
- Whatever else I haven't discovered yet!
Time to tally up the damage one last time in detail, start planning/budgeting, getting parts shipped out, and doing other work while I wait for them to come back...
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Be sure to get all new cir clips for your trans...
Replace them all...
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Oh yeah! That's a good idea... Any other must change/problem parts while I'm in here? Are worn circlips usually the cause of losing 3rd gear and other problems?
Also on another note, does anybody know if a crank rebuilder typically offers a service to weld or chrome up bad journals and regrind?
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I just rebuilt my kx250 bottom end due to a circlip breaking apart. Took out a gear and allowed the gear to rub the shift for. Grooved the fork but didn't damage it to bad. New clips equal cheap insurance.
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Ok guys... This is the part where I sacrifice (the remains of) my wallet to the great entity that is Kawasaki. I've fully disassembled the trans and every last bit of the engine, and prepared "KX Casserole" - I had a pretty easy time getting all the bearings removed from the case halves with the oven method.
It turns out that I spoke too soon, and found more damage in the transmission. As you know, the output shaft is boned due to badly worn chain sprocket splines. Ok fine. I found today that 4th gear (labeled 13260-1020 on the exploded diagram) is wallered out and the input shaft is galled in between the 2 circlips where it spins. So it looks like I need input and output shaft, and 4th gear... There is a trans assembly out of a 91 up on eBay right now for less than it'd cost for the shafts and gear. How common is this problem? Where does 3rd fail? How likely is it that these parts could come with the same problem?
[edit]: The bearings that I extracted from the case halves are the same as Motorrad mentioned in his thread:
Main: 2x Koyo 6306
Trans (L): NTN 6305, NTN SXO391 (OEM# 92045-0013)
Trans (R): NTN 63/22C3 (Plastic cage, of course...), Bushing (OEM# 92028-131)
Shift Drum: NSK 6905
KIPS governor: 608 (Make unk.)
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Ok, I finally got some images of the work so far... Won't need 1000 words if I can just show you guys!
Bike torn down:
(http://imageshack.us/scaled/modthumb/546/3mfi.jpg) (http://imageshack.us/photo/my-images/546/3mfi.jpg/)
The Barrel:
(http://imageshack.us/a/img35/8096/t76c.th.jpg) (http://imageshack.us/photo/my-images/35/t76c.jpg/)
Cracks in the usual places:
(http://imageshack.us/a/img545/4443/xpez.th.jpg) (http://imageshack.us/photo/my-images/545/xpez.jpg/)
(http://imageshack.us/a/img208/8325/a6r6.th.jpg) (http://imageshack.us/photo/my-images/208/a6r6.jpg/)
Peeling:
(http://imageshack.us/a/img11/6976/4py2.th.jpg) (http://imageshack.us/photo/my-images/11/4py2.jpg/)
Piston. It doesn't look all that worn.
(http://imageshack.us/a/img196/8393/2k5m.th.jpg) (http://imageshack.us/photo/my-images/196/2k5m.jpg/)
(http://imageshack.us/a/img20/2186/e7mw.th.jpg) (http://imageshack.us/photo/my-images/20/e7mw.jpg/)
(http://imageshack.us/a/img825/1728/q2n0.th.jpg) (http://imageshack.us/photo/my-images/825/q2n0.jpg/)
(http://imageshack.us/a/img35/2981/p05o.th.jpg) (http://imageshack.us/photo/my-images/35/p05o.jpg/)
KIPS Parts, one valve is broken:
(http://imageshack.us/a/img12/7545/d6u3.th.jpg) (http://imageshack.us/photo/my-images/12/d6u3.jpg/)
This part broke off, but continued to hold the valve to a degree
(http://imageshack.us/a/img401/8780/f704.th.jpg) (http://imageshack.us/photo/my-images/401/f704.jpg/)
Scored a transmission from a 1991 from eBay:
(http://imageshack.us/a/img839/9315/lnt5.th.jpg) (http://imageshack.us/photo/my-images/839/lnt5.jpg/)
Old shaft on the bottom for comparison
(http://imageshack.us/a/img202/677/n228.th.jpg) (http://imageshack.us/photo/my-images/202/n228.jpg/)
Close up of the galled section
(http://imageshack.us/a/img819/6382/vzpq.th.jpg) (http://imageshack.us/photo/my-images/819/vzpq.jpg/)
ID of the new gear, the old one was galled badly on the edges
(http://imageshack.us/a/img841/6705/zne3.th.jpg) (http://imageshack.us/photo/my-images/841/zne3.jpg/)
Output shaft looks ok, the output splines on the old one were trashed
(http://imageshack.us/a/img542/5456/n2om.th.jpg) (http://imageshack.us/photo/my-images/542/n2om.jpg/)
It came with a 1/2-13 bolt in it, Permacoiled back down to 1/2-20.
(http://imageshack.us/a/img22/9711/l4da.th.jpg) (http://imageshack.us/photo/my-images/22/l4da.jpg/)
Fumoto F101 drain valve installed. It's totally shielded by my skidplate, otherwise not a good idea. I intend to install it with Loctite red, and torqued firmly. Hopefully it stays.
(http://imageshack.us/a/img14/3680/k979.th.jpg) (http://imageshack.us/photo/my-images/14/k979.jpg/)
I machined the cross slots for more complete oil drainage.
(http://imageshack.us/a/img547/6097/5t6p.th.jpg) (http://imageshack.us/photo/my-images/547/5t6p.jpg/)
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A short video of the fit (if you could call it that) of the main bearing on the power take off side of the crank:
http://img825.imageshack.us/img825/738/ibfyjzxmcqiwvpmrhrzfpm.mp4
I plan to send it out to Crankworks, and have them build it back up, resize, rebuild/replace rod, and balance it. I'm going to use bearing retaining compound at least on the PTO side in hopes of this not happening again...
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Well, the cylinder and new Wiseco piston are out to US Chome. I'm gonna have the piston coated at the time time, as I'm a big fan of the black polymer coating when it comes to anti scuffing/seizing and (hopefully) taking up a little bit of that big clearance needed for this piston. Once it comes back, I gotta pack the piston back in a box with the crank this time, and get that sent out to Crankworks... In the meanwhile I'm trying to get everything else done.
This weekend, I used some classic, grade AAA s**tkicker engineering to make a soda blasting rig to clean the engine cases. Turns out it works quite well to clean the cases, and even better on the frame (right down to discovering more cracks the previous owner hid when he painted the frame... Ass): (http://imageshack.com/a/img829/9248/0qon.jpg) (http://imageshack.com/i/n10qonj/)Uploaded with ImageShack.com (http://imageshack.com)
(http://imageshack.com/a/img541/1172/cu7v.jpg) (http://imageshack.com/i/f1cu7vj/)Uploaded with ImageShack.com (http://imageshack.com)
(http://imageshack.com/a/img199/4686/i937.jpg) (http://imageshack.com/i/5ji937j/)Uploaded with ImageShack.com (http://imageshack.com)
BTW The fine baking soda flows at too great a rate (at least with this gun) if you just drop the siphon hose in the box and go to town, so the valve was added to bypass some air to thin out the mix. You could go nuts with a pressurized feed system or something using air/vibration that fluidizes the mix of soda/air going to the gun, but I didn't have time. You still have to shake the container and/or stick a finger over/block the valve once in awhile to create a vacuum pulse to dislodge clumps, but it works well enough to get the job done if you're patient enough. Baking soda is available at Wal-Mart at 2 bucks per 4 lb box. It took 4 boxes to do the cases and the frame... Pretty cheap.
After blasting, I fixed and welded up the broken front exhaust mount (closest to where the pipe hooks up to the cylinder), re welded one of the foot pegs, and the rear gas tank bracket that had cracks. I'll give it another blast to clean/roughen, then paint the frame. I was going to powder coat, but figured that if more cracks develop, I can repair it as I go and simply repaint. I guess I'm going for a good practical, rideable bike, since I'm sure I have a few falls and get offs coning in my future!
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Ok guys, so I have the front half of the bike put back together and am basically waiting for my cylinder and piston to come back so I can ship the crank (with the piston) for rebuild/balance. I have a couple questions I wanted to ask.
I've cleaned and washed the rear swing arm carefully, and wasn't able to notice grittiness or slop on any of the pivot bearings by hand. Obviously, 60HP worth of 2 stroke insanity is going to beat on it much harder than I ever could. How do you know when your pivot bearings are going bad? Slop?
This is probably putting the cart before the horse, but I was also wondering about forks too. I was reading that the early years have blue colored front forks that can be revalved to work adequately. But after going over to OEM-Cycle, it looks like the 1990 bikes have a special size fork for this year only. Can these be revalved? Can 1991+ "blue" forks bolt in or do you need a later year triple clamp? Should I just ride it, and save up to install KX450F forks, triple clamps, and custom stem (I could make the stem if I knew the dimensions)?
Lastly, how worn is worn when it comes to your chain guides? The 2 rollers that bolt onto the frame look fine, no play, no roller wear, but the rubber chain guide that goes around the front of the swing arm has some grooves in it, and the aluminum and nylon guide in the rear looks halfway worn through...
The nylon sides of the chain guide a
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Finally got the cylinder back from US Chrome... Having done some boring/honing work on Nikasil cylinders myself, I can definitely say that they did a beautiful job welding up the cracks, plating, and honing it. They even welded up the worn exhaust spring loops for me as I had requested. I had the piston coated at the same time... It's not as beautifully masked and applied as a factory coated piston (has a couple drips on the crown and the bottom of the skirts) though it should get the job done fine anyways.
I ended up using the Motorrad freeze/heat/bearing retaining compound method to install the bearings into the cases today. I took all of the bearings out of the package, and carefully wiped the OD clean with solvent, placed them in zip lock bags, and put them in the freezer overnight. I installed the crank seals with a light smear of case sealant, and put the case halves in the oven at 275 and let sit until hot. I took each bearing out, wiped the OD with paper towel to remove frost, wiped quickly with a light smear of Loctite 609, then quickly installed in the bore by hand, being careful not to get it in the races, or let it run down into seals, etc. I had a panic moment when one bearing stuck in it's bore and was beginning to expand, but managed to place the old bearing over it, and using a socket, drive it into the bore with a couple good smacks.
The crank and piston are on the way to Crankworks... Once it's back, it'll be time to try the hot socket on bearing inner race/freeze the crank trick.
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Ok guys, so I have the front half of the bike put back together and am basically waiting for my cylinder and piston to come back so I can ship the crank (with the piston) for rebuild/balance. I have a couple questions I wanted to ask.
I've cleaned and washed the rear swing arm carefully, and wasn't able to notice grittiness or slop on any of the pivot bearings by hand. Obviously, 60HP worth of 2 stroke insanity is going to beat on it much harder than I ever could. How do you know when your pivot bearings are going bad? Slop?
This is probably putting the cart before the horse, but I was also wondering about forks too. I was reading that the early years have blue colored front forks that can be revalved to work adequately. But after going over to OEM-Cycle, it looks like the 1990 bikes have a special size fork for this year only. Can these be revalved? Can 1991+ "blue" forks bolt in or do you need a later year triple clamp? Should I just ride it, and save up to install KX450F forks, triple clamps, and custom stem (I could make the stem if I knew the dimensions)?
Lastly, how worn is worn when it comes to your chain guides? The 2 rollers that bolt onto the frame look fine, no play, no roller wear, but the rubber chain guide that goes around the front of the swing arm has some grooves in it, and the aluminum and nylon guide in the rear looks halfway worn through...
The nylon sides of the chain guide a
the blue 43mm kayaba forks came in 91.. you have the 1990 41mm kayaba fork without rebound-adjusting, that were also used on the european 89 kx250 and 500s ...i think it could also be revalved , but you can update your bike with the blue 43mm forks or the later 46mm forks (97-2004) in any case you need the rigt clamps to the fork that you bolt in.
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While I'm playing the crankshaft rebuild waiting game, I've been doing some reading about rods... It looks like Hot Rods should be avoided? I looked around on Motosport.com and I don't think you can get the OEM rod anymore... What's my best choice? Vesrah? Pro-X (had a hard time finding one but think they may still be around)?
Crankworks is a Hot Rods distributor so I imagine I'll have to call and expressly insist on not using one if that's the case...
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While I'm playing the crankshaft rebuild waiting game, I've been doing some reading about rods... It looks like Hot Rods should be avoided? I looked around on Motosport.com and I don't think you can get the OEM rod anymore... What's my best choice? Vesrah? Pro-X (had a hard time finding one but think they may still be around)?
Crankworks is a Hot Rods distributor so I imagine I'll have to call and expressly insist on not using one if that's the case...
can still get stock rods from Kawi. after oem.. id run vesrah....
avoid hotrods... seriously....
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How do you know when your pivot bearings are going bad? Slop?
How worn is worn when it comes to your chain guides? The 2 rollers that bolt onto the frame look fine, no play, no roller wear, but the rubber chain guide that goes around the front of the swing arm has some grooves in it, and the aluminum and nylon guide in the rear looks halfway worn through...
Before I remove the swing arm assembly and shock from the frame, I put the bike on a stand and move the swing arm around.
If it is tight with no slop in any direction, then I disassemble and inspect each bearing.
If the bearing are smooth and not gritty and the inserts are shiny then I grease them up and go.
If I find any slop or gritty bearings or the bearings fall apart I replace everything..
On the rollers, if they aren't too worn and spin freely, just make sure that the surface isn't checked.
If the surface is smooth, run em.
Chain slider... as long as it's not allowing the chain to eat the front of the swing arm then it's usable... But if it's getting thin, I'd replace it to be safe.
Chain guide... as long as it's not allowing the chain to eat the mounting bolts then it's still usable... But if it's getting thin, I'd replace it to be safe.
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Well guys, after all the time, money, and painstaking work, it looks like I just trashed my shiny balanced, rebuilt crank. Look for a possible basket case for sale composed of all brand new unused top shelf parts for less than half of new cost...
I used the heat/freeze method, placing smoking hot sockets fresh out of the toaster oven on the bearings, but noticed that it wasn't really heating the bearing inner race up so I ended up assisting it with a heat gun until the bearings started to be a little hard to turn from the inner race expanding. I put sealant on one case half, grabbed the crank from the freezer, and wiped the journals with solvent, put a little bit of Loctite bearing retaining compound in there and after a quick reheat on the bearing with the heat gun, I dropped it in till it stopped.
It wasn't until I put the other half on that I noticed a slight gap. I gave the crank a smack with a rubber hammer, and started lightly tightening down the bolts. The crank was frozen and wouldn't turn. Closer inspection revealed that the crank didn't seat all the way down, and when I tightened the bolts, it bent the crank. I ended up pulling the ignition side case half back off, and noticed that the crank now has very visible runout after being bent. The crank is now bent beyond usefulness and frozen in the clutch side case half with no way to remove it short of pressing it out, which would undoubtedly destroy my nice new main bearings.
I really have to stop and decide on whether to just scrap the bike before I take anymore losses on this train wreck.
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That sucks man sorry to hear.
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I wonder if you can have the crank trued without having it completely rebuilt. Might not be much money just more time. I was looking at the crank shaft jig TOOL: 57001-1174 as some extra insurance.
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Ok, so using a hydraulic press, despite being glued in with Loctite 609, I was able to push the crank back out of the cases without any real abuse. In fact, the Loctite didn't seem to make much of a difference aside from that first initial "pop". The mains and case halves appear to have survived the ordeal undamaged. I suppose they're rated for several thousand lbs of dynamic force so a mere portion of shouldn't be a big deal, even axially, I guess.
Needless to say, I won't be using freeze/heat again... I never liked it to begin with. The principle is sound and it works fine when done right, but if anything hangs up or hesitates, you're screwed. It's strange, since the crank virtually fell right through the bearing and went "clunk" right up against the bearing, so I figured we were golden.
The crank is another matter. I put it in the lathe at work, and using my best Swiss made indicator, I gently drove a wedge between the webs, tapped with a mallet, and squeezed to try to get the crank straight again, but wasn't able to do the job satisfactorily. I took it down to Q&E down in Anaheim to see if they could get it straightened out. Worse case scenario, the crank cannot be straightened, and I'll have to buy a new crank assembly from Kawasaki. I'm debating on whether I'd want to have it balanced and trued on top of it... Let's hope it doesn't come to that.
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Ok guys... So I decided to put the crank in the hands of somebody who knows press together cranks, and hasn't played a continually losing game the whole way. He managed to get it straight to within .0025 or so on one side and .0015 on the other. That'll get the job done. I took it home and went to a friends house with a hydraulic press and pressed it right in without a hitch. On advice from the machinist, I fashioned some aluminum wedges to lightly tap between the crank webs on each side of the rod, put cardboard over the rails of the press to set the cases on, and pressed it right in. IMO the force required never came close to harming the cases or the bearings, and everything went together fine this time. So much so that I regret having tried any other way.
On a more familiar note though, I managed to break my new shifter shaft, and waste my brand new clutch nut and gasket as well. It turns out the stud that guides the shift shaft was not all the way down either, and when I (cautiously) tightened the cover down, I noticed that the shift shaft wouldn't shift. On investigation, it turns out that the stud held the pawl up, bending it. Attempting to straighten it resulted in it cracking. It turns out to be hard coated or nitrided or something. As I tried to bend it with pliers, the surface cracked and flaked like glass... Definitely scrapped now. So, in short, I spent 3 hours to trash 100 bucks in parts, and ends up worse off than I started, which now appears to be customary when working on a KX500.
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He managed to get it straight to within .0025 or so on one side and .0015 on the other. That'll get the job done.
I would really reconsider using that crank in it's current condition..
If I remember correctly you are right at the service limit.
In my opinion, K5 cranks need to be much closer then the book says.
I sent mine to Pinsonnault Racing and received it back in perfect condition.
I put my Test indicator on it and couldn't read any runout and I can measure .0001" with it.
Also, I reviewed Motorrad's heat/freeze method for crank installation and if you follow it precisely, and you have no defects in your parts, you should have no problems.
The only thing I do differently from Motorrad is skip the beers :lol: and I have had no problems at all...
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Ok guys... So I decided to put the crank in the hands of somebody who knows press together cranks, and hasn't played a continually losing game the whole way. He managed to get it straight to within .0025 or so on one side and .0015 on the other. That'll get the job done. I took it home and went to a friends house with a hydraulic press and pressed it right in without a hitch. On advice from the machinist, I fashioned some aluminum wedges to lightly tap between the crank webs on each side of the rod, put cardboard over the rails of the press to set the cases on, and pressed it right in. IMO the force required never came close to harming the cases or the bearings, and everything went together fine this time. So much so that I regret having tried any other way.
On a more familiar note though, I managed to break my new shifter shaft, and waste my brand new clutch nut and gasket as well. It turns out the stud that guides the shift shaft was not all the way down either, and when I (cautiously) tightened the cover down, I noticed that the shift shaft wouldn't shift. On investigation, it turns out that the stud held the pawl up, bending it. Attempting to straighten it resulted in it cracking. It turns out to be hard coated or nitrided or something. As I tried to bend it with pliers, the surface cracked and flaked like glass... Definitely scrapped now. So, in short, I spent 3 hours to trash 100 bucks in parts, and ends up worse off than I started, which now appears to be customary when working on a KX500.
Man that sucks...
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Well... The bike is running. Though I have seemingly endless reasons to be paranoid, I think that things are going to work out ok after all.
I thought about having the crank torn down and reassembled, or buying a new assembly and sending it out to be balanced and welded, but at this point, so over budget, the choice was pretty clear: get it together and ride this thing before the growing resentment and unending money pit ends up talking me out of the bike.
That said, at .0015-.0025 misalignment, if you think about it, it's likely that even kicking the engine over will cause the crank to deflect by that amount. All that vibration shaking a 230 lb bike around? It's being transmitted through those 2 bearings. Sure, I expect that it's lifespan will be effected, but I'm hoping to get my fill of good riding out of it before having to crack it open again.
Anyways, after I finished putting it together, I turned the gas on, held the kill button and gave it 2 kicks, and sure enough, it started on the very first kick once I released the button. The bike even idles now once warmed up - something it wouldn't do before no matter what I did. I let it warm up for 5 minutes or so until the rads heated up and carefully rode it around the neighborhood for 15 min the next couple of nights. Finally last night I took the bike out to the dirt after work and after riding around enough to be at full temp opened her all the way up - insane! Instant wheel spin and fishtailing unless I sat back off the tank some, and then, instant wheelies. I'm pretty sure that the KIPS is working right, as you can really feel it wake up and go apes**t once you're in the upper rev range.
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Good to hear you got it running. You'll be an expert for the next rebuild.
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Hey guys, been awhile so I figure that I'd report in now that the bike has been running for awhile. The power is even more amazing than I remember when first riding this bike, and so far, all of the gear whine rattling/rolling bearing noises haven't gotten louder or resulted in the engine exploding - so far.
The first thing I noticed is that it was eye watering, smoky rich off idle (55 pilot, needle 2nd clip), but cleans up after 1/3 throttle up to WOT fine (168 main). I'm at about 1000 ft., Weather has been around 60 degrees. The engine is stock, with a FMF Gnarly pipe and Turbine Core in bad need of repacking. O ring seal at the cylinder is nearly perfect due to slightly oversize O rings for a tight fit, new springs, and copper gasket. I eventually reduced the pilot to 52 with the needle at 2nd clip and it cleans up just off idle but the plug still comes out black and wet if I haven't hit WOT. I'm debating on whether to go further or leave it avoid potentially seizing the piston coming off WOT. Perhaps slightly richer on the main and slightly leaner on the pilot would be safer? I ride almost primarily in the desert.
Other shakedown problems include slowly weeping coolant from the head gasket on each side when the bike gets hot enough, and a slightly damp look with dirt collecting around the base gasket on the sides - it may be leaking. I know that I had to helicoil a couple head studs and one was sort of borderline when I put the head on. I may end up pulling the head and cylinder to inspect, helicoil head stud threads, and re gasket with Cometic gaskets or the like. It's got a factory base gasket and whatever paper with steel ring type head gasket came with the Wiseco piston kit.
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From what I read on this site those in the know recommend countersinking the head studs to make sure nothing gets pulled up. I countersunk mine just a bit might not be a bad idea if you take it back off anyway
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I think that US Chrome (or the previous owner) actually countersunk the stud holes. The top surface was lapped flat and everything, too. It's still possible that they pulled up, and it's possible that the one stud (and possibly others) that had weak threads decided to creep. I will probably pull the head and jug and helicoil the rest of the head stud holes on the mill just to be sure, counter sink again, and replace base and head gasket.
Anybody have recommendations for head and base gaskets? Cometic? OEM? I used an OEM base gasket but it looks like it may be leaking a tiny bit/collecting dirt. Maybe not, but the talk of sucking base gaskets scares me, so I want to put the best in while I can.
I was running the Wiseco HG that came with the top end kit, but it's not really top quality. It's a bit thicker than the steel gasket that came out - I'm trying to avoid having to mix in race gas and stick with CA 91 if at all possible. I don't need max power, just max reliability since it's going to be a desert bike used far from home.