[crf100rider21]

i am about to rejet my bike and i need to know what all to put on it

it pops and cracks on decel and when i rev it with the clutch in

i have a big gun pipe and a uni filter

don't know anything about the carb set up backus i bought the bike used

[gal8x]

you might want to install a Crf's Only fuel/air screw first, since you already have the power-up kit.
it will also help to know at what altitude you are riding.

[crf100rider21]

i'm in east tennessee

if that helps

the person i bought it from said it had the power up kit but i don't think it does

but idk

[13slick13]

crf100rider21,

If u have a big gun pipe and not the power up kit you'd know it. It would'nt run for .. All i did was take out the baffel and snorkle and mine ran really bad before i put the power up kit in. I already had the kit just wanted a before and after feel before i put it in.

[gal8x]

it pops and cracks on decel and when i rev it with the clutch in

if this is all the bike is doing then the fuel/air screw will alow you to fine tune your engine.

some "pops and cracks" are normal. i have found that when i tune them out completely the motor runs better when hot but, not that much... and it's harder to start.

i'm new at this too so i'm still experimenting. i'm convinced that with an after market pipe (i have a Pro Circuit T-4) the air box needs to be opened more.

take the cover plate off and you should notice a slightly faster throttle response.

i have the project on hold until after next month when i'll install a new piston and cam.

finding the right combination is important. there are a ton of threads here to help you just look around.

[crf100rider21]

i took the snorkel off one time and it ran horrible

it just bogged out every time i gave it gas

how would i tune out the pops?

[13slick13]

It should'nt bog with the snorkel out once it warms up. it is important that you tune your bike based on how it runs when it's warm as far as the poping on decel goes mine does that too but it runs great so i dont worry about it. When u do the power up kit most people only change the needle and main jet i was thinking of changing the pilot jet to, but idk i like it the way it is now but if you go up in your pilot jet size that may help you.

[gal8x]

i took the snorkel off one time and it ran horrible

it just bogged out every time i gave it gas

Ok let me give it to you strait. when a power up kit is installed you MUST complete the entire mod.
main jet, power up needle, snorkel and baffle.
if the mod is not completed you will eventually burn the motor.

of corse if your carb is filled with dirt then you must fix that first.

ok lets recap.
1) you were not the one who installed the mod. (if i remember). so you really cant be sure if the jet and needle are the right ones.
2) you have an after market pipe so it should not have a baffle,
3) pull the snorkel and the ring that holds it in.
4) you will want a free flowing replacement air filter (from Crf's Only). but a clean stock filter will work for now.

if the bike runs like poh then i would buy and install a new power up kit from Honda. they are only $40.

the power up mod is designed for a stock motor with a stock pipe. your bike (and mine) has a high prefomance pipe which is better than a stock pipe with the baffle removed. adjusting the fuel/air screw is the best way to retune to the new pipe. Honda has decided we are not to adjust the stock fuel/air screw with out first buying a special tool .
you can order from this link
http://store.azmusa.com/07kma-mn9a100.html

or here is another
http://www.hondadirectlineusa.com/valky ... &ID=363114


but i recommend you toss the stock "D" type and replace it with...
http://www.crfsonly.com/catalog/product ... 84322fa400
:!

[Aussiecrf230]

It is easiest to check what main jet you have, so do that first. If that is done there maybe a Powerup kit installed.

It only costs a little time and you need to check that first.

Anything in the 125-135 range should be close enough to run once past idle.

How does it run at half and full throttle?

Definetly get idle mixture screw sorted as well.

Then take it from there to make sure you have the right needle.

[crf100rider21]

it runs fine while givving it gas but somtimes it idles good and somtimes it won't idle and it pops

how do i tell what the main get it?

[RideRedForLife]

Is there any black stains around where your pipe is at the head? Mine was popping like that and it ended up being there was a very small exhaust leak at the head. I replaced the copper o-ring at the head pipe and it quit popping. Hope this helps...

[acjjkamp]

it runs fine while givving it gas but somtimes it idles good and somtimes it won't idle and it pops

how do i tell what the main get it?

almost sounds like an air leak, check the carb and make sure that the boots are seated correctly

main jet: take the carb drain plug off, unscrew the jet (6mm i think) the jet size is on the jet

[crf100rider21]

well now that it is hot out the bike runs alot better

no more pops so i guess it is good

[gal8x]

well now that it is hot out the bike runs alot better

no more pops so i guess it is good

Another good example of why you NEED a fuel/air screw from Ken. You can make those adjustments for weather, on the fly.

[crf100rider21]

well when i get some money i will look into buying one!