wont rev clean,smoking

[no sub for cubes]

hi all

i have just rebuilt my 88 kx500 engine after coming to the conclusion the crank seals had gone,the first time i started it before i pulled it apart it run great revved clean and after 2 3 times of running it started to smoke alot,sounded lumpy and would not rev clean.
Having completely rebuilt the motor new seal bearing etc i started her up first time today and exactly the same problem it wont rev clean sounds lumpy and smoking alot  ,the kips valves are opening when its revved so i dont think thats the issue,the air screws 1 half turns out as it says in the book,i put fresh fuel in it at 40/1.

One thing i have noticed before when it was running good adjusting the tickover screw i could get it to tick over and now it wont tick over adjusting the screw does nothing i can wind it all the way in and it does nothing...


                                  anybody any ideas?

[KX500freak]

maybe its carb issues ,
is the coneshaped floatpin still in good order?

if not, it allows the floatheight to rise so that can cause your issue.
it sounds to me tho its surging due to too many fuel which it can ,if the pin is worn ,
if the coneshape is not perfect  .it needs replacement .

i cant think of something else right now 

succes !

[cbxracer30]

You would hate to think it but maybe the crank seal you got for the waterpump side was bad from the get go and gave up already?  It stinks when you find out you got brand new bad parts. Could also be a bad head gasket , does it right away when you first start it up?CBX

[no sub for cubes]

cheers for replying guys

yes the motor bogs and smokes straight from start up,hard to belive after a full rebuild,i have replaced all bearings and seals that it given up the ghost again but like i said before i tore the motor apart with suspect main seals gone it run really sweet,just thought there might be another rational explaination for it.is their any other tell tale signs i can look for to confirm seal is leaking?


                     

[no sub for cubes]

i will pull the carb off tomorrow and check that kxfreak,like i said before when it was running good i could control the tick over by adjusting the throttle screw but now it doesnt do anything  ,it is almost like the choke is constantly on..is that a sign of the crank seals gone?

[Hillclimb#42]

It does sound like its flooding. Some kind of float problem maybe. Reeds ok?

[KX5Zuki]

Some thing that I ran into, and chased around for a while before, you could have a leak in the cases from the tranny. Check your tranny fluid, is it low? Or have gas in it? I had that issue once before on a KX125 I had. hard to track down, and you could do more harm than good by "fixing" what isnt wrong.

[KX500freak]

Some thing that I ran into, and chased around for a while before, you could have a leak in the cases from the tranny. Check your tranny fluid, is it low? Or have gas in it? I had that issue once before on a KX125 I had. hard to track down, and you could do more harm than good by "fixing" what isnt wrong.

i don,t see any harm done by tearing the carb down ,
also a reeds check like hillclimb mentioned in the same time
atleast sub for cubes knows the carb is proper and still in good order,or not   

[no sub for cubes]

Well pulled the carb off and checked that,needle rubber looks fine,float height was fine and no blocked jets,also i pulled the reeds out they looked ok,i pulled the plug out and it was oily and black looking i peared down the plug hole and it looks like the top of piston is same condition an oily black colour.
It started easy no choke needed ,and for about 15secs sounded ok but after that started to smoke more and wouldnt rev clean,does this sound like seals gone again ? im thinking so.

[Speedway73]

Sounds like it's sucking oil from the tranny either from the seal or center case gasket.

[no sub for cubes]

thats a good point speedway same as kx5zuki suggested,i had an issue with oil leak between the case halves before i pulled it apart,i have cured that now since the rebuild,the k5 does not have a gasket between the case halves which i learnt when pulled it apart and found that very odd but thats how they are meant to be so i used a decent case sealer and its cured the leak but it is a possibilty its leaking between the gearbox into the cylinder.
looks like i will be pulling it apart again and another rebuild  ,i have an 87 engine i bought for spares anybody any idea if the cases are the same as the 88?maybe i will swop the case over and use them.

[KX5Zuki]

The cases are different. Sorry. But if you want to get rid of the kickstart gear assembly let me know.

[no sub for cubes]

oh cheers for letting me know that,i bought the motor because i did some research and could see alot of the 87 88 bits are the same,so i am hanging onto the parts that are interchangeable  shame about the cases i knew they were diff part no but look pretty similar


                                            thanks anyways

[cbxracer30]

If you haven't torn the motor down yet I would do a leak down test. This will let you know if the seals and or the seal between the 2 inner cases is bad.CBX

[no sub for cubes]

hi cbx

no not pulled the motor apart yet,yes to do a leak test before i pull it apart this time might be a smart idea,forgive my lack of knowledge here but how do i perform a leak test ?