KX Riders
Maintenance & Technical => KX250 / KX125 => Topic started by: andydunne on November 06, 2011, 06:17:02 AM
-
Hey guys, I took the head off my bike today for the first time since I got it just to have a look. When I did so, I noticed a few things a miss, here is what the head looked like, with the exhaust valve(blue) sitting way off, is it hard to see how this bike was running fine??
(http://i556.photobucket.com/albums/ss8/mivec86/DSCF07301-1.jpg)
Here is what the intake(red), exhaust(blue) valves looked like when i took them out, the teeth on both of them are very worn and chipped! The gear marked green wasnt chipped or damaged at all btw!
(http://i556.photobucket.com/albums/ss8/mivec86/DSCF07361-1.jpg)
And here is what underneath the exh. valve looked like when I took it out, the piece of metal underneath the exh. valve looked melted and is jammed in a port to the exhaust pipe?
(http://i556.photobucket.com/albums/ss8/mivec86/DSCF07311.jpg)
Now I know little or nothing about how this stuff works only presuming it involves the powervalve? But surely the above is not right, I could see the little bar/slider the valves were supposed to lock into but in their shape they were surely missing this bar/slider alot of the time!
So can anyone shed some light on whats going on and will the above be affecting my bikes performance?
-
:-o
Umm.. Yes...I think your bike has a few issues that need to be addressed..
I think I have some pages from a manual that my help.. Let me see if I can find them.
Tuck\o/
http://www.kxriders.com/coppermine/displayimage.php?album=lastup&cat=1&pos=67
http://www.kxriders.com/coppermine/displayimage.php?album=lastup&cat=1&pos=71
http://s69.photobucket.com/albums/i75/Friar-Tuck/KX%20500/Kips%20Valve/
-
good thing you can still get new valves from kawasaki. and they are like $40 ~ each
-
Thanks Tucko that gives me a better understanding now of what is going on, a few parts have most definitely had their long life ha!
Yes 1989kawasak, I seen that on the Kawi website, not too bad at that price imo. So with that I hope to order new ones from my local Kawi dealer tomorrow! It will be back running in no time not that it wasnt running well, I was at the track recently and the bike never missed a beat all day and always has rode perfect. Hopefully more power when its sorted :-)
-
Andy are you able to get a service manual?
I think K-wack mentioned a european E-bay of some sorts you may be able to find a used one. The Kawasaki service manual might even be cheaper from your dealer if you don't have to pay shipping. It will be well worth you money and can be recouped if you decide to sell the bike later...
There are several pages of those books if you spend some time snooping around the links in the prev post.
I'm pretty Daft when it comes to computer stuff so the pages aren't in order, you have to look around...
Tuck-O \o/
-
New valves have been ordered hopefully will have them next weekend :-)
Andy are you able to get a service manual?
I think K-wack mentioned a european E-bay of some sorts you may be able to find a used one. The Kawasaki service manual might even be cheaper from your dealer if you don't have to pay shipping. It will be well worth you money and can be recouped if you decide to sell the bike later...
There are several pages of those books if you spend some time snooping around the links in the prev post.
I'm pretty Daft when it comes to computer stuff so the pages aren't in order, you have to look around...
Tuck-O \o/
No I havent even looked for one Tucko, might be handy to get one though!
Here is a few I seen on ebay;
http://www.ebay.com/itm/120606255525?_trksid=p3984.m1423.l2649&item=120606255525&cmd=ViewItem&sspagename=STRK:MEWAX:IT&vxp=mtr
http://www.ebay.ie/itm/330629304132?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
http://www.ebay.com/itm/160605500707?_trksid=p3984.m1423.l2649&item=160605500707&cmd=ViewItem&sspagename=STRK:MEWAX:IT&vxp=mtr
Im not sure if any of them are any use, is a service manual and a owners manual the same thing?
-
New valves have been ordered hopefully will have them next weekend :-)
Andy are you able to get a service manual?
I think K-wack mentioned a european E-bay of some sorts you may be able to find a used one. The Kawasaki service manual might even be cheaper from your dealer if you don't have to pay shipping. It will be well worth you money and can be recouped if you decide to sell the bike later...
There are several pages of those books if you spend some time snooping around the links in the prev post.
I'm pretty Daft when it comes to computer stuff so the pages aren't in order, you have to look around...
Tuck-O \o/
No I havent even looked for one Tucko, might be handy to get one though!
Here is a few I seen on ebay;
http://www.ebay.com/itm/120606255525?_trksid=p3984.m1423.l2649&item=120606255525&cmd=ViewItem&sspagename=STRK:MEWAX:IT&vxp=mtr
http://www.ebay.ie/itm/330629304132?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
http://www.ebay.com/itm/160605500707?_trksid=p3984.m1423.l2649&item=160605500707&cmd=ViewItem&sspagename=STRK:MEWAX:IT&vxp=mtr
Im not sure if any of them are any use, is a service manual and a owners manual the same thing?
no, service is not the same as owners
-
Thanks mate, Ill keep an eye on that
-
Hey guys, I took the head off my bike today for the first time since I got it just to have a look. When I did so, I noticed a few things a miss, here is what the head looked like, with the exhaust valve(blue) sitting way off, is it hard to see how this bike was running fine??
if you think it was running fine like that your in for a nice surprise when you get it fixed :evil:
-
andy, I would advise buying a clymer manual(this is a generic KX manual, covering all capacities), and then a yr specific genuine Kwak kx125 manual, and they do a tuning (general, not porting stuff) manual too, also yr and model specific..if you cant find em (ebay search, set to worldwide) gizza shout and I'll have a gander. you should have most of the bed time reading you'll ever need.K.
-
Hey guys, I took the head off my bike today for the first time since I got it just to have a look. When I did so, I noticed a few things a miss, here is what the head looked like, with the exhaust valve(blue) sitting way off, is it hard to see how this bike was running fine??
if you think it was running fine like that your in for a nice surprise when you get it fixed :evil:
Ye I hope so, I have a 50 toooth sproket ordered also so it with the new valves should be different anyway :-)
-
andy, I would advise buying a clymer manual(this is a generic KX manual, covering all capacities), and then a yr specific genuine Kwak kx125 manual, and they do a tuning (general, not porting stuff) manual too, also yr and model specific..if you cant find em (ebay search, set to worldwide) gizza shout and I'll have a gander. you should have most of the bed time reading you'll ever need.K.
Thanks fot that mate :-)
-
I removed what was left of the subvalves, the one on the right was wedged between the shaft it sits in and the exhaust port, here is how they look :-o
(http://i556.photobucket.com/albums/ss8/mivec86/DSCF07411.jpg)
-
Eee Gads Mate!
X's 2 on having a surprise when you get the girl back on her feet.
Tuck\o/
-
Oh stop, they are in a state.
I ordered a clymer service manual earlier too, it might educate me a bit :lol:
-
I got the new valves today, much better
(http://i556.photobucket.com/albums/ss8/mivec86/DSCF07421.jpg)
(http://i556.photobucket.com/albums/ss8/mivec86/DSCF07431.jpg)
I will probably get a mechanic to fit them as I am unsure which way to position them. The mechanic in mention, is the top Kawasaki mechanic in Ireland and is only 10mins from my place, so it would be foolish not to bring the bike to him and have her running sweet :-)
-
those look so sweet. those wont be available for too much longer unfortunately
so sit and gawk at them while they are new :wink:
they discontinued the valves for my 89 kx250 years and years ago..
but i am interested to hear the improvements you will gain from those.
-
Ha im going to sleep with them tonight :lol:
I noticed the 88 kx125 valves are different to the 89 and they are discountinued, so im lucky they are still available.
I cant bloody wait :-)
-
A little bit of an update, I got a new Clymer manual so I found out how to replace the powervalves and the collars above them myself. Couldnt believe the size and detail of the manual, it made the job simple. So I put everything back together,all timed up , everything clean, new base,head,pv,exhaust gaskets, fresh fuel, air filter etc.
Cylinder was in good condition no marks etc.
With that I tried to fire the bike, wont fire at all with a kick so I got my bro to push me and kick it into gear, the bike then attempts to fire but makes a bogging sound for 2/3 secs and then dies. Before it always was difficult to get her going after lying up for a while but usually 1 or 2 kicks when used regularly.
The plug is wet when i check it.
I am getting a spark, although the plug isnt new but it looks fine. I have both br8eg and br9eg plugs, not sure if there correct?
Havnt touched any of the jets or slider on the carb, same as before.
Maybe the compression isnt great, I was thinking this before I started any work. So I will test the cylinder for compression, it would be a good start right?
About 300-400 feet above sea level
4-5 degrees celcius, if they help!
Any tips would be good, not the most detailed sorry
-
I have tested the compression in the topend and it is making 90psi. This is without warming the engine beforehand as I cant start the bike atm which probably isnt ideal.
What is this figure like?
Is it time for a new piston and rings?
-
yeah,it's more than ready.anything under 150psi,and it's starting to get on the weak side....just my opinion.
Foxx
-
I have tested the compression in the topend and it is making 90psi. This is without warming the engine beforehand as I cant start the bike atm which probably isnt ideal.
What is this figure like?
Is it time for a new piston and rings?
Did you hold the throttle wide open when testing the compression?
If you don't it will cut your PSI reading drastically.
-
yeah,it's more than ready.anything under 150psi,and it's starting to get on the weak side....just my opinion.
Foxx
Thanks for that mate, it is pretty low alright. It always was hard to start when not riden for a few weeks but fine when out riding. Low compression would make it harder to start right, as my mate reckons it should start even if it has only 10psi, but i doubt that :?
-
I have tested the compression in the topend and it is making 90psi. This is without warming the engine beforehand as I cant start the bike atm which probably isnt ideal.
What is this figure like?
Is it time for a new piston and rings?
Did you hold the throttle wide open when testing the compression?
If you don't it will cut your PSI reading drastically.
No I didnt touch the throttle when testing it, I will test it again today to make sure I did it right!
-
It will not start well under 80ish psi. As said earlier WFO throttle position, kick it 8-10 times, read gauge, for proper comp test. If under 125psi new top end time, and probably more.
If you want you can pour a "LITTLE" 2 stroke or any oil in the cyl, then slowly kick thru the stroke a few times (spark plug out) reinstall plug then try to start it it will smoke more but it should boost compression enough to start easier.
Also if you don't start your bike for a few weeks it is alot easier to start if you lay her on her side. That will drain the carb bowl, and then start with fresh fuel in the carb bowl. It will also flood her a little and help start her when she's cold.
Bob W
-
It will not start well under 80ish psi. As said earlier WFO throttle position, kick it 8-10 times, read gauge, for proper comp test. If under 125psi new top end time, and probably more.
If you want you can pour a "LITTLE" 2 stroke or any oil in the cyl, then slowly kick thru the stroke a few times (spark plug out) reinstall plug then try to start it it will smoke more but it should boost compression enough to start easier.
Also if you don't start your bike for a few weeks it is alot easier to start if you lay her on her side. That will drain the carb bowl, and then start with fresh fuel in the carb bowl. It will also flood her a little and help start her when she's cold.
Bob W
Thanks mate, I did all that but still nothing happening. With the throttle open I am still only getting 90psi so I think its time for a new piston and rings! I will measure the cylinder for size and wear.
Any opinions on piston choice, I can get a Mitaka piston for 50 euro or so, but would I be better off spending a little more for a Wossner, Wiseco piston. Are the Mitaka cheap for a good reason?
-
Said id throw up a few pics seeing as I am bored and cant ride..
Clymer manual i got a few weeks back, by god does this make life easy, never would have touched the piston etc only for this
(http://i556.photobucket.com/albums/ss8/mivec86/DSCF07491.jpg)
Here is my piston removed, no real damage afaik, just a few small nicks at the edges. Im waiting on tools(calipers,gauges etc) to arrive to check the cylinder size, ring gap and other tolerances according to the manual so when I order a new piston its correct! Does this piston look stock?
(http://i556.photobucket.com/albums/ss8/mivec86/DSCF07451.jpg)
(http://i556.photobucket.com/albums/ss8/mivec86/DSCF07461.jpg)
I am going for a Wossner piston kit probably, they are pretty good right?
-
beware of wiseco piston kit, i bought a wiseco and the rings end gap is way to big .069" should be at .014", the part numbers are correct so some how the manufacturing is wrong because i measured my old ring and its at .014" i even ordered another ring and it measures the same .069" im not the only one who has had this issue. i called wiseco and they are of no help said they would send me correct rings but its been three days now and no show, will have to call again. all i can do is look at my bike and wish i was riding. if id known this i would of just ordered oem piston.
-
Cheers dude, I dont think ill be touching a wiseco piston, they dont have a good name here anyway.
I might just price a stock piston versus the wossner I was going to buy, stock seem to have the least amount of complaints :?
-
I did a few checks today with the manual at hand,
Piston ring end gap is 1.04mm(0.04") which is beyond service limit.
Piston ring groove width is around 1.06mm(0.04") which is beyond service limit.
Piston to cylinder clearance is roughly 0.05mm(0.0020'') which is good thankfully.
So now, I need to measure the piston and cylinder for size to be sure they are stock, so I order the correct size new piston. Is a vernier calipers an adequate tool for measuring these??
-
I ordered a Wossner piston kit from the UK last night, cant wait for it to arrive.
In the meantime I have ordered a new clutch and throttle cable, clutch lever and swingarm bearings, I really should start a proper thread of the bike :lol:!
-
Fitted new piston and rings without any problem.
Tightened everything back up and after a little issue with the carb, 2nd kick and BOOM combustion :-D
I have the swingarm arm off atm, changing bearings, so I didnt run the bike for too long while on the stand. I cannot feckin wait to have her moving, run it in and give her welly then :-D
-
Finally got around to riding the bike properly today. Absolutely delighted with how it ran and my new found power :-).
Firstly, the bike starts on first kick every-time now, which makes life very easy!
The new powervalves have made a big difference, much more top end, when before it seemed to go flat after the middle.
The bike feels quicker and snappier overall, whether its down to greater compression or me being rusty :-D
Real happy with her now and am surprised how everything is working after doing all the work by myself without an ounce of previous knowledge. Onwards and upwards now hopefully, thanks for all the help btw guys :-)