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1996 KDX200 Jetting Issues at altitude

Posted: 03:27 pm Jun 19 2022
by linny
Hello,
I'm back in the KDX mafia after picking up a project KDX200 for fun.

I've rebuilt the carb and I've still been having jetting Issues. I'm running way rich to where it bogs when I crack the throttle.

Here's the breakdown
V-Force 3 carbon reeds
FMF gold pipe stock silencer
Opened airbox
91 octane pump gas with octane booster to around 98.
50:1 premix

Kehin PWK carb with a 148 Main and 42 pilot, needle in 3rd position. Air screw 2 turns out. Currently air screw does nothing as it's TOO DAMN RICH :oops: 4300 foot elevation.

My googling is giving me settings all over the board with people swearing it's the best.

I'm at the point where I ordered a size 140 main and 35 pilot. Am I crazy here?

Re: 1996 KDX200 Jetting Issues at altitude

Posted: 03:41 pm Jun 19 2022
by Molly's 70
Try replacing your jet block gasket. You tube it.

Re: 1996 KDX200 Jetting Issues at altitude

Posted: 03:55 pm Jun 19 2022
by linny
That's a new one for me. I ordered the $7 gasket and we'll see what happens!

Re: 1996 KDX200 Jetting Issues at altitude

Posted: 05:23 pm Jun 21 2022
by linny
While waiting for my gasket to show up I blew out and cleaned all the passages in my carb - better but still too rich. Think it's time for a new jet block gasket.

Re: 1996 KDX200 Jetting Issues at altitude

Posted: 06:21 pm Jun 21 2022
by SS109
The jet block gasket has frustrated many people over the years. If I can't seem to get the jetting right I'll test it just to make sure.

Re: 1996 KDX200 Jetting Issues at altitude

Posted: 09:14 pm Jun 22 2022
by linny
I went to a bike shop with some old guy there telling me NOT to mess with it and how I must be doing something wrong 🙄 and how they don't go bad blah blah blah.

Re: 1996 KDX200 Jetting Issues at altitude

Posted: 12:21 am Jun 23 2022
by SS109
linny wrote: ↑09:14 pm Jun 22 2022 I went to a bike shop with some old guy there telling me NOT to mess with it and how I must be doing something wrong 🙄 and how they don't go bad blah blah blah.
That old guy is an idiot. I have personally seen it go bad on three different PWK carbs. Plus, if they didn't go bad then there sure wouldn't be a replacement part available!

BTW, how to check the jet block gasket...


Re: 1996 KDX200 Jetting Issues at altitude

Posted: 11:44 pm Jun 23 2022
by linny
Yes he was - he also kept interrupting me to tell me to do a pressure test with freeze plugs blah blah blah, I had a friend blah blah blah.

I bought a $50 Chinese Kehin clone off Amazon and it braaped right up properly with full power. I'm going to fix the original Kehin and put it back on I was just in a pinch this weekend and needed something so I could ride.

Re: 1996 KDX200 Jetting Issues at altitude

Posted: 12:36 am Sep 07 2022
by billie_morini
linny, that jet block gasket cause trouble for me, too, earlier this year. Did not know it existed until forum members assisted. Like you, it was impossible to correctly jet the carb - always rich and plugs were wet afterwards.