KDXRIDER.NET

Guys, need your expertise to solve this mystery. Recently installed the above new carb w/ 1988 boot. With the stock settings it ran fine but would not idle no matter how i set the idle and air screw. As such I thought i needed a larger pilot. Once the new pilot was installed it initially started and ran similar until it bogged down like running out of gas and stopped. From that point on it would not start unless WOT and when it did it would start at an idle an die regardless of what did w/ the throttle. When i pulled the plug just to make sure i had spark (i did) smoke (unburnt fuel) starts coming out the plug hole. When I looked at the plug it was very wet. So i changed the plug and she fired up after two kicks like normal. Smoked a ton until it seemed like the excess fuel was burn off. At this point I assumed the pilot was too large so i went back to the original. Unfortunately the same problem with starting happened again w/ the original pilot and something close to original settings. So here i am total confused on why I’m having issues starting and when it does start why can’t i get it to idle. Please note the top end is new. Any help would be greatly appreciated.

How is the engine mechanically? Compression good? Have you done a leak down test to eliminate the possibility of air leaks? Stocking the carb came with or the stock jetting for the '86 KDX?

Leak down was fine, carb came w/ stock setting from Keihin for what i believe is for a kdx200, good compression (new top end)

You sound way too rich to me, not lean. You went the wrong way.

How is the jetting compared to an OEM '88 carb? I know it is not an air stryker, but still.

Yeah, what main, pilot, slide cut, and needle are you running?

So I finally figured out the issue. Yes it was rich, but mostly because it was not getting enough air. THe reason for this is because I was concerned setting the carb w/o a filter and the risk of sucking in any dirt that falls off the frame. What I had done was put a thin tee shirt over end of the carb, but this had too much drag and low surface area resulting in air starvation. When I pulled the shirt off she ran. Reduced the pilot from 55 to 50 she would idle. Raised the needle one and changed the main from 160 to 155. Still need to recheck if its lean at WOT, but she friggin rips now. Checked the plug and the color was brown-black. THe other learning is not only do I need an 1988 engine side boot, but I also needed the 1988 air box side boot for it to seal up properly to air box and engine. Foots a little sore from all the kicking, but glad she’s running well. Thx for all of the ideas/help!

Are you telling us that this whole time you had a tee shirt over the cab and not a normal airbox and oiled air filter?