Flat spot on takeoff

[michaelbell85]

So trying to tune my carb starts up and runs then when i bob the throttle for take off i get a bog.After the bog it runs like hell.Do i needle to adjust needle or possibly buy a bigger slow jet.Got a 30mm oko carb 48slow 148 main in it now.

 

[vspec]

what mods do you have done?

 

[blasterdemon7]

How many turns is your air screw at?

 

[Quadrider10]

mine did the same a little, but dosent matter for me, cause i gots new b1 pipe,and i have to rejet anyways I:I

 

[michaelbell85]

2 screw on air screw,piped,head mod,lightened flywheel

 

[brandoz28]

does it get better if you take the air screw in?

 

[Awk08]

yep, as dakota said,
what airscrew setting does it idle the highest and rev clean to 1/2+ throttle ??
1/2 turn or under = larger pilot (slow)
over 2 turns out = smaller pilot
floats must be to spec first

then move on to adjusting needle clip position, then main jet

 

[Quadrider10]

thats what i imagined u would have to do. try turning the air screw clockwise 1/4 turn to lean it a little.

 

[brandoz28]

thats what i imagined u would have to do. try turning the air screw clockwise 1/4 turn to lean it a little.

turning it clockwise will richen it

 

[Quadrider10]

turning it clockwise will richen it

my bad..... counter clockwise.... dont listen to me!

 

[blasty 95]

What awk said lol.....

 

[blasterdemon7]

yep, as dakota said,
what airscrew setting does it idle the highest and rev clean to 1/2+ throttle ??
1/2 turn or under = larger pilot (slow)
over 2 turns out = smaller pilot
floats must be to spec first

then move on to adjusting needle clip position, then main jet

Yuuuuup. Awk's right on it.

 

[Quadrider10]

Yuuuuup. Awk's right on it.

What awk said lol.....

FINE! BE THAT WAY! lol

 

[michaelbell85]

ten four will try tomorrow i thin k its getting to much air no air box pod filter if that matters

 

[Awk08]

ten four will try tomorrow i thin k its getting to much air no air box pod filter if that matters

straight pod filter directly on the carb ??? ......notoriously hard to tune,
needs a "velocity tube" 4-6" to allow the air to straighten out before hitting the carb

 

[brandoz28]

straight pod filter directly on the carb ??? ......notoriously hard to tune,
needs a "velocity tube" 4-6" to allow the air to straighten out before hitting the carb

true story! this has been battled by a lot of people, add the tube and try it again. this may sort out the issue

 

[michaelbell85]

where do i buy the stack from

 

[Awk08]

pvc pipe and "fernco" fittings, from any hardware, plumbing, lowes, home depot stores

 

[brandoz28]

all you need is a straight piece of tube and then a coupler to put it on the carb. just get a piece of exhaust tube or similar that's the same OD as the filter side of the carb, then get a fernco coupler to put them together. you can do a little tuning with the length to see what it likes

 

[Awk08]

heres a couple older threads on the subject, and a few pics down in them........

http://www.blasterforum.com/engine-...mp-filter-velocity-stack-balancer-tube-40139/

http://www.blasterforum.com/body-15/air-box-24581/