palbunch

Member
Apr 22, 2008
5
0
Put newBoysen reeds in moved the jet needle down 1 notch from middle to lean a bit, also I was told to adjust the air screw in 1/4 to 1/2turn and do test. I cant find an air screw just the idle screw facing out towards me . Does any one have diagram of a 87 kdx carb, or know where to adjust air on carb?
 

Core87

Member
Jul 4, 2006
23
0
Hi palbunch, I have two of these carbs and neither of them have an adjustment for the air screw. The only adjustments can be made by changing the low speed jet/ idle jet. If the new reeds require a richer setting then 5 to 10 larger on the idle jet should be enough. second from the bottom on the needle is factory setting according to my w/shop manual. Always check the plug colour if in doubt.
 

palbunch

Member
Apr 22, 2008
5
0
Thanks Core87


I believe i have a #320 main jet stock and Boysen says to go down with the main jet 1 size to start.I was told middle on the jet needle was stock I moved it down 1 to lean according to Boysen. My plug does seem to be black so I guess I am to rich, that is why it is bogging at mid to full throttle.
Everyone tells me there should be an air screw.
 

glad2ride

Member
Jul 4, 2005
1,071
1
There is not an air screw on the 1987 KDX200. There is on 1988+, but not on the 1987 (and some earlier versions).

Start with your pilot, as it affects all other circuits.
 


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