Low rpm bogging
Posted: 06:09 pm Mar 31 2024
On my 1993 Kdx200 its bogging really bad in the low and lower middle rpm ranges. It pulls decently once you get on the pipe.
FUEL:
I don't think it is jetting as I have tried everything from 155-140 main and 48-36 pilot with every step in between. I've landed on 35 pilot and 150 main 3rd clip position and the air screw about 2.5 turns out. It also idles really bad. The air screw seemingly does nothing and it will only stay alive if you have the idle adjust turned all the way in.
With the carb out it looked really clean inside and the guy who had it before me had ultrasonically cleaned it, I also adjusted the floats. So again I don't think its a fuel issue. (32:1 oil ratio)
SPARK:
I checked the timing and it was right on the arrow and the spark on the head while my buddy kicked it over looked maybe a little dim but it was definitely sparking.
COMPRESSION:
It passed a compression check with flying colors showing strong numbers right off rip
AIR:
The intake tract has no cracks on the inside of the boots and I just put in the Boyesen Power reeds thinking it was that. it idled really well one time when we tried it with no air filter but once it warmed up some it went back to crappy.
Here is a video where I ride it in 1st gear on my street. I was about 3/4-7/8 throttle there and it barley accelerates.
Before we changed the jetting a bunch it would surge and die really fast in that range almost like you were spamming the kill button. its a little better than that now but it still feels messed up.
Any advice appreciated I'm really at a loss for what to do here
FUEL:
I don't think it is jetting as I have tried everything from 155-140 main and 48-36 pilot with every step in between. I've landed on 35 pilot and 150 main 3rd clip position and the air screw about 2.5 turns out. It also idles really bad. The air screw seemingly does nothing and it will only stay alive if you have the idle adjust turned all the way in.
With the carb out it looked really clean inside and the guy who had it before me had ultrasonically cleaned it, I also adjusted the floats. So again I don't think its a fuel issue. (32:1 oil ratio)
SPARK:
I checked the timing and it was right on the arrow and the spark on the head while my buddy kicked it over looked maybe a little dim but it was definitely sparking.
COMPRESSION:
It passed a compression check with flying colors showing strong numbers right off rip
AIR:
The intake tract has no cracks on the inside of the boots and I just put in the Boyesen Power reeds thinking it was that. it idled really well one time when we tried it with no air filter but once it warmed up some it went back to crappy.
Here is a video where I ride it in 1st gear on my street. I was about 3/4-7/8 throttle there and it barley accelerates.
Before we changed the jetting a bunch it would surge and die really fast in that range almost like you were spamming the kill button. its a little better than that now but it still feels messed up.
Any advice appreciated I'm really at a loss for what to do here