lo 206 stuttering at 4400 rpm

tmrace25

Member
Hey guys, new to karting, i have a a 206 that im having problem with it stuttering at 4400-4500. running the red slide i believe its .440 height.
not sure what i need to do, i took the carb completly apart cleaned it good.
set it back up at;

float height .895
drop at 1.050
3rd c-clip
mixture screw at 1 turn out.

any help would be appreciated, thanks .
 
Make sure that it has all 3 brass ball plugs in place of the air circuit machining/tooling entrances.
If you cleaned it with brake clean and compressed air...this could likely be your problem.

Also check all the normal stuff (I'm sure you already have):
coil wire inserted tightly at both ends
spark plug is gapped (.023") and clean
coil air gap is sufficient (.016")
head gasket not leaking
valve lash is set correctly (ie not on overlap cycle)
float drop tab doesn't slip over the top of the post (common problem)
Fuel filter not plugged
Fuel valve turned on and not plugged
Fuel tank has proper venting
Catch can for the carb overflow has adequate venting (not run together with the valve cover vent)

-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
30 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
How about checking that the 2 clips that hold the needle in the slide are installed correctly.
 
Often times they will run ok that way but give it a try.
 
i think i figured it out, my pulse line was to long, and oil was puddling in it, would that create a stutter?
Bigger question might be "why is oil puddling in the pulse line?"
Over filled with oil?
Not enough crankcase ventilation (ie catch can not filtered or vented from valve cover breather?)
 
Is the catch can large enough volume, big enough filter, large enough line, etc?
14 ounces and mount is fine.
You might try running the engine without the breather line connected and see if that stops pushing the oil up the pulse line as much.
Just how long was your pulse line?
 
Briggs recently added another 6X1mm threaded hole so you can mount the fuel pump with the pulse line pointed directly towards the pulse fitting in the top of the side cover. However, You will have to drill and tap the other hole to secure the pump properly.
Gravity helps to drain Oil that might get into the hose back into the crankcase.
KIMG0995_1_-600x450.jpg
KIMG0996_1_-600x450.jpg

This eliminates the long hose that loops around the kill switch and usually develops a low spot for oil to accumulate.;)
 
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Is the catch can large enough volume, big enough filter, large enough line, etc?
14 ounces and mount is fine.
You might try running the engine without the breather line connected and see if that stops pushing the oil up the pulse line as much.
Just how long was your pulse line?
it was around 13 inches
 
it was around 13 inches

Even with the stock fuel pump mounting position, 7" is about as long as you need.
Like Jimbo said, running this line a bit shorter will help keep it from sagging and collecting oil.
I still prefer the original pump positioning over the add'l hole that has been added. If you rotate the pump, then you've got the inlet line to the carb looping under the throttle cable (and Kwik Link if you're running one.)
 
Make sure that it has all 3 brass ball plugs in place of the air circuit machining/tooling entrances.
If you cleaned it with brake clean and compressed air...this could likely be your problem.

Also check all the normal stuff (I'm sure you already have):
coil wire inserted tightly at both ends
spark plug is gapped (.023") and clean
coil air gap is sufficient (.016")
head gasket not leaking
valve lash is set correctly (ie not on overlap cycle)
float drop tab doesn't slip over the top of the post (common problem)
Fuel filter not plugged
Fuel valve turned on and not plugged
Fuel tank has proper venting
Catch can for the carb overflow has adequate venting (not run together with the valve cover vent)

-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
30 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
is there a way you can tell if the brass plugs are still in the air circuit machining entrances?
 
I'm gonna tip toe in here.
You should be able to see where they drilled the intersecting passages .
outside .
In order to see them all you may have to remove the float bowel to see any under there.
 
is there a way you can tell if the brass plugs are still in the air circuit machining entrances?

There are three brass ball plugs ( a little smaller than 1/8" - .100" actually) right next to the main jet and emulsion tube - they're all on the opposite side from the float -- you can see them without removing the float, but you'll at least have to remove the float bowl to see inside.
 
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