bogging out

[DannyBeavis]

i have a 1991 kdx 250 and the bike has recently had the ring changed and has had the piston cleaned because the bike bogged out just after i hit the powerband and smoked heavily. As it turned out the silencer needed repacking as it was clogged with oil. The bike no longer smokes as heavily but still bogs out after i hit the powerband. I was reading a previous thread which said the bike needed rejetting. If this is the case could someone tell me how i need mine jetted and how to do it please as i am a novice.
The bike has the stock silencer and expansion pipe, as well as the snorkel still on the filter.
Any help will be greatly appreciated thanks.

 

[kdx220freak]

well first off jetting is not easy if you have never done it before. but once you have done it, it is easy. FIrst make sure your airfiler is very very clean, or your jetting will be off. Then if seems like you need to lean your main jet up. Say you have a 155 in now i would try a 150 and see what it does. Do you know what jetts you have in the bike now and what is your elevation and temp??

 

[DannyBeavis]

I have absolutely no idea, but i dont think the jetting will have been changed in the bikes lifetime, as the person who owned it before me had it imported and prior to that it was used on the road. The air filter is absolutely filthy will that make a difference? and do you think it is because of this the bike is bogging out or is it common to all kdx's

 

[kdx220freak]

Definatly the air filter reguates the air flow, if it cant get air it will bogg. Clean it. When i got my bike a few months ago the airfilter was clogged horribly, the bike smoked alot and the preformance was lacking, after i cleaned it, it ran much better and did not smoke as much. This may not be your whole problem but i can garantee if the air filter is not clean you may ruin your bike. Also make sure you put some air filter oil on it when you are done. This will collect the small particals that will clogg your carb. So clean that filter!!!!!!!!! :)

 

[kdx220freak]

i have to go out to eat now, but i will be back in a few hours, if you have any more questions just ask and i can answer them (if i know the answer) in a few hours. But clean that filter.

 

[kdx220freak]

use a degreaser or a ton of like dishwasher soap cause it is impossible to clean them with just water.

 

[DannyBeavis]

Cheers mate its the next job on the list.

 

[lepper]

I'd check the KIPS.... sound like it's not opening to me...

 

[DannyBeavis]

When i had the exapnsion pipe off i checked the kips it seemed to be working fine but that was only when i pulled the valve myself. mite i have tightened the arm 2 much, and can i tighten the arm when the kips valve i slightly out so it is open longer?

 

[lepper]

You can take the left screw cover off and see if the shaft is turning at around 6K...

 

[trevor morgan]

Definately get that filter cleaned, you may want to remove the snorkel from the top of the air filter box too to free up the air flow, made a noticable difference on mine. With regard to jetting its hard to say because each bike is different but if your jets are standard they will be 165 main and 42 pilot. I changed mine for 160 main and 38 pilot, made the bike rev cleaner and higher. Whilst your repacking the tail pipe remove the mechanical baffle that sits in the middle, doesn't alter the noise too much but again frees some more power.