So I’ve posted a few threads on here trying to solve this bogging from idle stabbing to wot issue and also looked online a lot some people even suggest that it’s a four stroke thing and can’t be solved. I may have solved mine at least. Refer to the crappy illustration as I explain. We all know the accelerator pump gives an extra shot of gas upon acceleration to help with the sudden increase in air. I had my carb open (03 400ex) and noticed the cam that activates the plunger begins flat and eventually activates the lever bout a third of the way in. It’s not a free play issue, the start of the cam is literally flat (red area) and it does not depress the plunger until the little knob (pink dot) reaches the green area of the cam. If you stab while you’re in the green area you take off… "yeah bro you’ll learn it’s a four stroke thing just get your rpms up before you stab it ride in a higher gear blablabla". So if you are accelerating with your accelerator pump squirt no bog but accelerate without it you bog. If they knew this carb would starve for fuel upon quick acceleration why would they design it to only give extra gas after a quarter or third throttle. I tested it by manually depressing the accelerator pump rod at the exact same time as I hammered the throttle an it revved like an Indy car from complete idle. Armed with this new info, I bent a small piece of spring steel (3/16 inch wide 1/8 thick, actually a piece of a fish tape I’m an electrician) around the knob at the end of the arm, pink dot, and the pivot point of the arm, yellow dot. The blue line is where I put the spring steel and the black lines indicate where I tie wrapped it to the arm. Had to rebend it a few times to get it working well but basically the green area of the cam touches my new piece as soon as thecam starts moving and activates the accelerator pump as soon as you crack any amount of throttle as opposed to waitingfor the pink knob to make it through the red area before activating it. I haven’t done extensive testing yet the wife is about to strap a bomb to my quad but I rode to my mailbox an back and it was responding like an RC car. From any rpm to every rpm, from complete idle I hit it to wot as fast as I could (in wet grass) and straight to rev limiter. Is this something that’s been done before I’ve seen taffy mods and Bernie mods but I think those are on fcr carbs in 450s. Am I at risk for anything bad to happen? Also had to bend the tab that touches the pump rod back a little to compensate for the added thickness of the Springsteen between the cam and the knob. All thoughts ideas and comments welcome
Carburetor masters lend me your ears
So I’ve posted a few threads on here trying to solve this bogging from idle stabbing to wot issue and also looked online a lot some people even suggest that it’s a four stroke thing and can’t be solved. I may have solved mine at least. Refer to the crappy illustration as I explain. We all know the accelerator pump gives an extra shot of gas upon acceleration to help with the sudden increase in air. I had my carb open (03 400ex) and noticed the cam that activates the plunger begins flat and eventually activates the lever bout a third of the way in. It’s not a free play issue, the start of the cam is literally flat (red area) and it does not depress the plunger until the little knob (pink dot) reaches the green area of the cam. If you stab while you’re in the green area you take off… "yeah bro you’ll learn it’s a four stroke thing just get your rpms up before you stab it ride in a higher gear blablabla". So if you are accelerating with your accelerator pump squirt no bog but accelerate without it you bog. If they knew this carb would starve for fuel upon quick acceleration why would they design it to only give extra gas after a quarter or third throttle. I tested it by manually depressing the accelerator pump rod at the exact same time as I hammered the throttle an it revved like an Indy car from complete idle. Armed with this new info, I bent a small piece of spring steel (3/16 inch wide 1/8 thick, actually a piece of a fish tape I’m an electrician) around the knob at the end of the arm, pink dot, and the pivot point of the arm, yellow dot. The blue line is where I put the spring steel and the black lines indicate where I tie wrapped it to the arm. Had to rebend it a few times to get it working well but basically the green area of the cam touches my new piece as soon as thecam starts moving and activates the accelerator pump as soon as you crack any amount of throttle as opposed to waitingfor the pink knob to make it through the red area before activating it. I haven’t done extensive testing yet the wife is about to strap a bomb to my quad but I rode to my mailbox an back and it was responding like an RC car. From any rpm to every rpm, from complete idle I hit it to wot as fast as I could (in wet grass) and straight to rev limiter. Is this something that’s been done before I’ve seen taffy mods and Bernie mods but I think those are on fcr carbs in 450s. Am I at risk for anything bad to happen? Also had to bend the tab that touches the pump rod back a little to compensate for the added thickness of the Springsteen between the cam and the knob. All thoughts ideas and comments welcome
