2005 KTM 125 power valve adjustment?

[Simon Aamand Enevoldsen]

so i just got a ktm 125 2005 and it couldent evan keep up with a yz 85 so i oppened the power valve inspection port and when i turn the adjuster it seems like there is a lot of slack in it how do i solve this problem?

[7Tktm]

Hi, with the left hand pv cover off (the one with the breather pipe) check that the valves are opening. Give the bike a real hard rev and you should  see a bracket with a stroke in it turning down to the bottom of the 'window' and returning back up to the top as you return to idle. Check that first. Bob

[seer]

 The valves in the head are all gear driven. Mine had slop and needed replacement. As it was the transfer ports would only open about half way. 

 Yours sounds like possible wear at the governor attachment. 

[Simon Aamand Enevoldsen]

4 minutes ago, seer said:

 The valves in the head are all gear driven. Mine had slop and needed replacement. As it was the transfer ports would only open about half way. 

 Yours sounds like possible wear at the governor attachment. 

and is that an easy fix?

 

[seer]

1 minute ago, Simon Aamand Enevoldsen said:

and is that an easy fix?

 

I cant say whats easy for you. You need to pull the cover off to replace but i wouldnt order anything before diagnosis ing. 

 

[Simon Aamand Enevoldsen]

5 minutes ago, seer said:

I cant say whats easy for you. You need to pull the cover off to replace but i wouldnt order anything before diagnosis ing. 

 

and how do i know for sure its the governor attachment? and if it is the governor attachment where can i buy a new one an not an used one

 

 

Edited December 3, 2018 by Simon Aamand Enevoldsen

[7Tktm]

Hmm. Have you checked that the valves are opening yet when you rev the bike? It is the most common problem. The 'governor' or centrifugal timer is a foolproof mechanism. The only thing that goes wrong with it is for the one or more of the 4 ball bearings jumping ramps which stops the valves opening fully. Easy to fix yourself but you would need to remove the clutch cover. You would be best to check the valves are opening first to ensure the system is actually connected, but if you don't want to then it's up to you. Bob

Edited December 3, 2018 by 7Tktm

[Simon Aamand Enevoldsen]

1 hour ago, 7Tktm said:

Hmm. Have you checked that the valves are opening yet when you rev the bike? It is the most common problem. The 'governor' or centrifugal timer is a foolproof mechanism. The only thing that goes wrong with it is for the one or more of the 4 ball bearings jumping ramps which stops the valves opening fully. Easy to fix yourself but you would need to remove the clutch cover. You would be best to check the valves are opening first to ensure the system is actually connected, but if you don't want to then it's up to you. Bob

i haven't checked yet because its late when i come home from work and i woudent like to piss of my neighbors

[7Tktm]

Ah, ok. There is a process you go through with the power valve which is a very simple but good system. First is to make sure it is meshed. If so then move on to next stage. All it requires is a quick rev, even when cold, to see if it is opening. We run our bikes up and down the street when issues - must have good neighbours. Bob.

Edited December 3, 2018 by 7Tktm

[Simon Aamand Enevoldsen]

16 hours ago, 7Tktm said:

Ah, ok. There is a process you go through with the power valve which is a very simple but good system. First is to make sure it is meshed. If so then move on to next stage. All it requires is a quick rev, even when cold, to see if it is opening. We run our bikes up and down the street when issues - must have good neighbours. Bob.

i have just checked and it seems to be opening but the mark in the power valve i way beond the 2 marks on the non moving part. and when it opens it goes down to the top mark

[7Tktm]

Hmm. For the factory setting (which we prefer) - when idling the inner stroke should be higher than the fixed lines then when you rev it hard the moving line travels down almost out of sight at the bottom of the inspection window. That is how it should be set to give you power through the whole rev range.  Have you tried adjusting the moving stroke back up to the top then see how far it travels when revved hard

Edited December 4, 2018 by 7Tktm

[Simon Aamand Enevoldsen]

32 minutes ago, 7Tktm said:

Hmm. For the factory setting (which we prefer) - when idling the inner stroke should be higher than the fixed lines then when you rev it hard the moving line travels down almost out of sight at the bottom of the inspection window. That is how it should be set to give you power through the whole rev range.  Have you tried adjusting the moving stroke back up to the top then see how far it travels when revved hard

i havent tried that but it pulls more with that setting so i dont think it would help

[nobade]

If the adjuster has a lot of slop in it (more than 1/4 turn) the link arm is worn and the power valve won't open all the way. It's a wear item, costs $35, and is easy to replace. It's behind the inner cover, attached to the timer.

[7Tktm]

Agree it's an older bike, possible the control lever is worn where it runs up the shaft. I've re-read his last thread and it appears, if I am reading it correctly, that the control segment is at the top of the 'window', ie flap and valves closed, but when he revs it is only opening as far as the 'control' mark on the securing plate. Certainly have to remove the clutch cover and check the control lever to see if it has a half circle worn in the end and also check the ball bearings haven't jumped ramps which deffo stops the pv from opening fully.