walbro carb help

Hello i have got a wt.257 carb and i need some installation help. I got the throttle cable all worked out already. i sealed the pulse port on my stock manifold as i read its useless with this carb. Which way should i install the carb. the little brass circle thing in the carb facing the manifold or away from it? I have already set the needles. If there is anything else i need please link me to it! thanks

come on anybody?

The side with the brass butterfly goes towards the motor. But before you install it you better check that 257 for a pulse hole which is on the motor side of the carb. If you look on that side of the carb you will see 2 small holes and if you look at the hole that's closest to the plate on the bottom that says Walbor and has the idle screw attached to it you'll see in that hole that there is a little hole on the inside of that hole that's the pulse hole. If you look in the other hole it goes nowhere it's just a indention. now I've never used the Wt257 carb but I've use many other Wt's and other Walbor carb. I've been around here along time and I've never heard anything about blocking the pulse hole in the manifold for the 257 other than filling in the bottom half of the oblong hole in the manifold. The only thing I've really heard is it doesn't have a return fitting so you need to block it at the tank. Like I said I never used that carb and I maybe wrong but I thought you should at least check that carb for the pulse hole. Now if you have a link to where you read it wasn't needed I would like to read it. Now the reason I never used a WT 257 or even the WT603 carb is I feel their to small and have always used carbs with a bigger venturi than 12.7mm like 15mm + venturi. The stock carb most times is a 15mm carb so I feel using a carb that smaller than stock is like going backward. Not to say that your bike won't run good with the 257 carb I'm sure it will as I always heard good things about it but I've never run 1.

so your telling me i can use a bigger carb then my wt-603? so i kan go even faster? ......by the way i have a x1

I think that's what I said and I know you have a X1. I run a 16.5mm purge carb on my fully modded X2. The thing with going to bigger carbs is that the pulse hole doesn't line up with the pusle hole in the stock manifold. So either a adapter plate needs tobe made or it has tobe turned into a purge carb by adding a fitting to the carb and to either the manifold or into the case or even into the cylinder at the transfer port so the carb can get it pulse as that is what runs the fuel pump in the carb. Unless you get a purge carb that has a fitting already than you only need to add it to the motor as posted above.

Well the link is right here i managed to find it in the how to section and did i have to do it because i have no problem getting rid of the jb weld thats in there if its needed. Is there any adaptor plate needed for this wt 257 carb? im new to these walbro carbs sorry for all the questions. I just want this carb installed properly so i can have the bike up and running once again. thanks edit: i see what you mean on the location of the pulse port.I am currently getting rid of the jb weld and then im gonna mount the carb then cover only the exposed part of the pulse port on the manifold!

As long as you keep the bottom half of the oblong pulse hole filled in the manifold you don't need a adapter plate.

k well i got the carb on and the needles set but now it wont start>:/

Ok where do you have the High screw and low screw set at? Do you have a choke?

yes i have a choke and the low speed needle is at 1 1/4 turns out and the high speed needle is at 2 turns out. It is getting spark also i just checked it.

Ok try turning the Low screw in a 1/8th turn and see if it helps. Does it fire over at all? Do you have the idle screw turned all the way to the right?

It does not fire at all the carb is clean i checked for compression and spark and the pulse port in the manifold is all good its getting gas i checked by putting my finger in the carb where the air filter goes and pulling a few times and my finger came out wet. Yes the idle screw is all the way in. I even twist the throttle while trying to start it but still no go

So there's no little rumbles at all when trying to start it? What color is the spark?

No nothing. The spark is a brand new ngk bm7a. i checked it for spark while i was installing it. The spark color was a bright blue.

Still no turning on. What can be wrong with this. It doesnt sputter or anything

After dayss of trying guess what? still no go. come on guys i really want to get this bike up and running help me here!

Do you have a choke with your setup? If you do I'm sure you have tried the choke in different positions like closed,half open and open right? Have you turned the Low screw in to 1 1/8 and 1 turns out? Have you tried any starter fuild? Take the airfilter and V-stack off and post a pic of the carb so I can see it the same way it's on the motor? If you have spark,air,fuel and compression it should start. But since it's not even sounding like it wants to start it sure sounds like your coil is bad but try spraying alittle starter fuild into the intake and see if it starts for a few seconds. If it does your coil is good but if it doesn't it maybe bad. Sometimes when you test them with no compression they can show a good blue spark but once under compression they don't have a good spark.

Alright well last night i got it started using a slightly larger battery that would actually spin the motor for more then 10 seconds at a time. It ran like crap basicly:P. It wont start with the pull start but im pretty sure with a little tuning i can change all that! Each time i let go of the throttle the rpms would lower to the point that it would just die and this is with the idle screw all the way in!. It didnt rev as high either but ill be doing some tuning once i get a new manifold because the brass inserts in mine slide out too easily not allowing me to tighten the carb completely.

hi i have a cateye 49cc pocket bike 49cc engine i just bought a walbro 603 carb and dont know how and what to put where to put it please help thanks

I had the same problem. My bike wouldnt stay idling, it would run but only above half throttle.
Sounds like you still have an air leak going on.
While its running spray some WD-40 around the intake and look for a reaction.
In order to use the aftermarket carbs you need to buy the adapter plate.
Such as this one Walbro Intake adaptor for 49cc Mid bike

Hope this helps