Author Topic: Fixing problems with new (old) bike. - Running  (Read 16568 times)

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Offline MeanGreenMachine

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Re: Fixing problems with new (old) bike: Pictures are up
« Reply #15 on: September 01, 2013, 06:45:32 AM »
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:


The Barrel:


Cracks in the usual places:



Peeling:


Piston. It doesn't look all that worn.





KIPS Parts, one valve is broken:


This part broke off, but continued to hold the valve to a degree


Scored a transmission from a 1991 from eBay:


Old shaft on the bottom for comparison


Close up of the galled section


ID of the new gear, the old one was galled badly on the edges


Output shaft looks ok, the output splines on the old one were trashed


It came with a 1/2-13 bolt in it, Permacoiled back down to 1/2-20.


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.


I machined the cross slots for more complete oil drainage.


Offline MeanGreenMachine

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Re: Fixing problems with new (old) bike: Pictures are up
« Reply #16 on: September 01, 2013, 07:27:27 AM »
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...

Offline MeanGreenMachine

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Re: Fixing problems with new (old) bike: Pictures are up
« Reply #17 on: September 07, 2013, 04:44:03 PM »
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): Uploaded with ImageShack.com

Uploaded with ImageShack.com

Uploaded with 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!


Offline MeanGreenMachine

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Re: Fixing problems with new (old) bike: Questions? Guys?
« Reply #18 on: September 21, 2013, 07:58:11 AM »
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

Offline MeanGreenMachine

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Re: Fixing problems with new (old) bike
« Reply #19 on: September 28, 2013, 03:08:53 PM »
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.

Offline motopunk

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Re: Fixing problems with new (old) bike: Questions? Guys?
« Reply #20 on: September 28, 2013, 04:58:13 PM »
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. 
big 2 stroke bikes are weapons for real men, who don´t fear death or devil. ;O)
´83 kx250, ´87 kx250 (with 360 big bore), 87 kx500, ´93 kx500 sfc

---  www.der-motopunk.de.tl  ---

Offline MeanGreenMachine

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Re: Fixing problems with new (old) bike - Crank Is Out... Which Con Rod?
« Reply #21 on: October 02, 2013, 02:13:56 PM »
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...

Motorrad

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Re: Fixing problems with new (old) bike - Crank Is Out... Which Con Rod?
« Reply #22 on: October 02, 2013, 02:25:11 PM »
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....

Offline sandblaster

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Re: Fixing problems with new (old) bike: Questions? Guys?
« Reply #23 on: October 02, 2013, 02:40:21 PM »
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.
« Last Edit: October 02, 2013, 02:58:18 PM by sandblaster »
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline MeanGreenMachine

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Re: Fixing problems with new (old) bike... Game Over...
« Reply #24 on: October 29, 2013, 04:26:25 PM »
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.

Offline Pmcg

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Re: Fixing problems with new (old) bike... Game Over...
« Reply #25 on: October 29, 2013, 04:32:31 PM »
That sucks man sorry to hear.

Offline Pmcg

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Re: Fixing problems with new (old) bike... Game Over...
« Reply #26 on: October 30, 2013, 02:46:55 AM »
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.

Offline MeanGreenMachine

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Re: Fixing problems with new (old) bike... Game Over...
« Reply #27 on: November 02, 2013, 08:47:45 AM »
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.

Offline MeanGreenMachine

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Re: Fixing problems with new (old) bike... Game Over...
« Reply #28 on: November 11, 2013, 03:04:47 PM »
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.

Offline sandblaster

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Re: Fixing problems with new (old) bike... Game Over...
« Reply #29 on: November 12, 2013, 04:11:48 AM »
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...
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.