125-200cc wr 125 not running as it should!

[smalldubster]

125 wr 2007 tmx 38
I just got a simple question, i use 400 main-jet, and 3% oil mixture. i dont know what stage my needle are at, but does someone know a good setup on my carb to make my bike run clean?

I live in Norway, and we have around 10-20 C in temp depending each day. Basically i want my bike to run clean, and much acceleration as possible. my sprockets are 13-45


Thanks for all answer, and sorry if anyone feels my post annoying, im new to this forum

anyways drive safe!

Edit: carb and model year is now editet, sorry !

 

[Bill502]

You need to tell the year of your bike so people here can help you, as there are two different carbs for the older and newer bikes.

 

[Coffee]

Thanks for all answer, and sorry if anyone feels my post annoying, im new to this forum

In no way is your post annoying. Please don't hesitate to ask questions. That is what the forum is for.

 

[smalldubster]

main post editet

 

[Bill502]

You can search here and get some ideas,http://www.cafehusky.com/forums/showthread.php?t=9400 but keep in mind that you have the TMX carb for 2008 and earlier not the TMXX as used on 2009 and up or as some have switched to the Keihan PWK.
Bill

 

[pvduke]

http://www.cafehusky.com/forums/showthread.php?t=8039

which part of the "thottle opening" are you having issues with and what is it doing?

do you have a lot of jetting experience w/ a 2-cycle? if not i suggest a dealer or a shop to get you in the ball park.

if you want to do it yourself:

* if the carb is the orriginal-
make sure your air filter is clean, your bike is ready to race- fully serviced, no mechanical issues!

* start with your main jet at least one size, maybe two sizes larger than factory recomended, the needle clip in the middle slot, the slow jet @ factory recomended size and the AS 1.5 turns out. use a new plug AFTER warming up your bike.

* INSTALL A NEW PLUG in the warmed up engine. find a flat open space. start the bike, get it rolling right away and rev it out in 1st, 2nd and 3rd gears at least- till it hits the limiter- you want it to be as clean of pulls as possible. then, pull in the clutch, hit the kill switch and chop the throttle closed NOW, do NOT let it idle. then coast to a stop, READ THE PLUG. dark brown? good. anything lighter and it's too lean.
this is how you establish your baseline main jet size and you are safe and can now make adjustments if needed for top end performance once your low speed circuits are tuned.

* next you can adjust your air screw/slow jet for off-throttle snap, and, your midrange tip-in to 3/4 TO with the needle- BE VERY VERY CAREFUL IF YOU LOWER THE NEEDLE.
always start rich and got lean in very small increments and ONLY DO ONE CHANGE AT A TIME.
one you get your low speed circuits dialed in you only need to change the main for large elevation changes, for the most part, sans a very small tweak of the AS.

* make one change at a time. read the plug often.

* if you find you're needle clip is close or at the bottom or the top- stop and change the main.

* it takes time and RIDING to jet a 2 stroke and never take for granted anyones recipe for jetting. always verify your recipe by reading the plug. then, get a marking pen and write the jet sizes on the float bowl.

* when you park your bike for the week- ALWAYS DRAIN YOUR CARB AND TANK.

any ? please PM me etc....or ask here.

 

[dartyppyt]

PVduke,

You did a nice job of explaining that!

 

[smalldubster]

http://www.cafehusky.com/forums/showthread.php?t=8039

which part of the "thottle opening" are you having issues with and what is it doing?

do you have a lot of jetting experience w/ a 2-cycle? if not i suggest a dealer or a shop to get you in the ball park.

if you want to do it yourself:

* if the carb is the orriginal-
make sure your air filter is clean, your bike is ready to race- fully serviced, no mechanical issues!

* start with your main jet at least one size, maybe two sizes larger than factory recomended, the needle clip in the middle slot, the slow jet @ factory recomended size and the AS 1.5 turns out. use a new plug AFTER warming up your bike.

* INSTALL A NEW PLUG in the warmed up engine. find a flat open space. start the bike, get it rolling right away and rev it out in 1st, 2nd and 3rd gears at least- till it hits the limiter- you want it to be as clean of pulls as possible. then, pull in the clutch, hit the kill switch and chop the throttle closed NOW, do NOT let it idle. then coast to a stop, READ THE PLUG. dark brown? good. anything lighter and it's too lean.
this is how you establish your baseline main jet size and you are safe and can now make adjustments if needed for top end performance once your low speed circuits are tuned.

* next you can adjust your air screw/slow jet for off-throttle snap, and, your midrange tip-in to 3/4 TO with the needle- BE VERY VERY CAREFUL IF YOU LOWER THE NEEDLE.
always start rich and got lean in very small increments and ONLY DO ONE CHANGE AT A TIME.
one you get your low speed circuits dialed in you only need to change the main for large elevation changes, for the most part, sans a very small tweak of the AS.

* make one change at a time. read the plug often.

* if you find you're needle clip is close or at the bottom or the top- stop and change the main.

* it takes time and RIDING to jet a 2 stroke and never take for granted anyones recipe for jetting. always verify your recipe by reading the plug. then, get a marking pen and write the jet sizes on the float bowl.

* when you park your bike for the week- ALWAYS DRAIN YOUR CARB AND TANK.

any ? please PM me etc....or ask here.

<

Thank you very much
I have some experience yes about the throotle, the problem is that at low rpm in 4-5 & 6 gear and when i go full throotle the bike dies.. but only on very low rpm. Before i had 420 main jet, and i had this problem all the time.

about the spark plug, i will do that

Anyways, thanks for all the fast and good answers !

 

[pvduke]

PVduke,

You did a nice job of explaining that!

thanks man. i like helping my husky buds out.

the problem is that at low rpm in 4-5 & 6 gear and when i go full throotle the bike dies..

oooo- that's a tuffy cuz im not sure what throttle opening you started at in 4-5-6 gear... try raising the needle (lowering the clip/richening it) one notch. if that does not work, put the clip back in the middle and go up one size main jet and retry. if it dies when you whack it open it's probably lean.


do your baseline main jet verification as i outlined above. check the chart in the link, go by throttle opening, not RPM at first. w/ some tinkering in about 20-30 mins youll have it safely screaming. meeeeeeeeeeep! meeeeeeeeeeeeeeep!

 

[smalldubster]

sweet, il give som feedback, about the results !
cant wait to hear that meeeep sound

 

[Motosportz]

Are you riding this on the street because 13/45 is real tall gearing. For woods work I run 13/52 with a 144 kit.

 

[rockdancer]

It must be road - I second the 13f /52 rear

I have had an 06 and 08 wr 125 with that carb . With a 380 main but mainly hotter more humid here
You may need to adjust the needle to suit the condiitons - winter /summer
A low throttle bog is normmally too lean try a richer needle setting - - clip one from bottom setting or lok at the pilot jet size

read up on carb tuning It will not always be perfect though

 

[R_Little]

I have the same carb and run a 380 main.

I'd try a 390 and see what happens.