Walbro Wt-603 New carb Problems

Hey everyone, Glad to be apart of the forums here, SO I bought a Giovanni M3 pocket bike from ebay, I couldn've been happier with it untill it started ****ing out gas after about 2 weeks of mild use from the overflow on the carb, After watching a friend **** with his carb for hours and hours on end (the float bowl kind) I just decided to buy a new one, The Wt-603, So I got it all on yesterday, Tighest fit Btw, you'll see from the pics... So once it was all finally On, the choke valve was stuck..... ***?? All off again to realise that the gasket that goes between the wt-603 and the stack Was Just too small preventing the choke valve from opening, it was stuck closed. SO After the dremmel came out to make that hole bigger in the gasket this time I put the carb together with the choke Off and it's finally all assembled! Next I put the second hole in the gas tank for the return/supply fuel line, install the new fuel line, no leaks from the tank! Good, So Now, I hook both the fuel lines up, and when pressing the primer ball the carb only pushes air/fuel back into the tank and the ball DOES NOT fill with fuel, I have some sort of problem, I've tried and can't seem to figure out why theres no suction from the other line coming from the tank. Heres some pics to help! Thanks for any and all help!

I also put the thread in general discussion, It probably fits better here.

i have the same carb. yes they are a pain -- that is not a primer bulb -- the bottom line is inlet and top is return. i had the same prob with chhokoe not opening all i did was have it full open then assembled it and it worked

Hey thanks for your Reply! I'm still not getting what I'm missing tho lol, The Ball doesn't fill with fuel when pressed and only sends fuel up the return line and doesnt suck any in Any ideas?

dont press the bubble!, thats not a primer bulb, that sendes air up the line causing the gas to go up, air is bad!

if u remove the fuel line from the carb does gas pour out?

yea the ball is not to be primed it will fill somewhat while fuel is circulating through.

Maybe that primer doesn't fill because that screw is loose and it's sucking air into it. You should of put the return line close to the top of the tank so it dumps into the tank. It can't return fuel from the bottom. The fuel only wants to go down from the bottom I would think. The primer bulb only primes the carb not the motor. It should fill about 3/4 full at least. Is there fuel in both lines? I can't tell in the pic's.

you know it does look like the one screw in the back the talll one is lose you can see threads under the head . tighten thhat up too. i see you removed the top plate to run the throttle through

I don't know if he can tight it up it looks kinda bugered up.

also that loop that goes under the carb, just take it straight across instead of going under the carb

Yeah the original throttle Piece hit the motor and wouldnt fit on, it came with an extra, that thing you see there is a spacer, the screw is tight, they all are, I Took the carb off and the stack off and when I hooked up the carb alone to the gas tank it still only sent air/fuel up when pressing the ball, I know the ball should fill up with gas, Nothing gets sucked up from the inlet at the bottom of the carb, not gas not air, Somehow the ball is drawing air from somewhere other than the inlet to refill itself back up, It'll be coming apart tonight once i get about 3 people here lol, I figure theres something clogging that inlet, Pain in the ***! Any suggestions and help are still welcome and thanks to every1 who did reply

Pics, The first pic is the carb , the bottom is the inlet and theres another on the top, When the ball is pressed it pumps air into the return line, I'm assuming that it should be pumping Gas but for some reason the inlet doesnt take anything in and it pumps air instead of filling up and pumping gas through?

This does make sence, in a way, If I did indeed put the hole in the wrong spot, I put it beside the origonal hole btw any way to patch it somehow? And, How is the guys who said he had the same carb, Did you have to drill a new hole for your return line? And where did you put it?

Did you clean out the plastic shavings from the tank after drilling the hole for the return line? Sorry had to ask I would think you would of. You really don't see fuel moving through the fuel line but you will see it flow through the return line because of the bubbles. That's how those carbs are. When you pull the fuel line off the carb does gas flow out of the fuel line? After you try and start it is the sparkplug getting wet at all? Can you smell fuel on it? Can you tell Me where the H and L mixture screws are set at? Like how many turns out they are.

nah i installed that on my cateye and that already had a return line.

Yeah, Cleaned the tank, Filters in the supply line too, When I remove the line and the gas tank is above the bottom of the line the gas does pour out, But I'm like 100% that the carb isn't taking anything in, The screws arn't set But According to http://www.adaracing.com/pdf/pbhpck47-wt.pdf
it says the high screw should be set at 2 turns open and low at a turn and a quarter, I'm going to do this now. I'm like 100% that nothing is getting into the carb via the supply line and inlet, Probably gonna take it apart and see why nothing will flow through it, Thanks for any and all help.

hey man i did some searching and i came across something that should be useful

''The fuel line on many units has a 1/4" line, which can allow bubbles to collect, especially in hot weather (fuel percolating). Even at full throttle the fuel flow is not sufficient to move the bubbles from a high spot in the line, where they eventually collect and slow fuel flow enough to cause performance to decrease. A solution with which many have reported success is to use a smaller 1/8" (~3mm) line,''

i read this on a website, nothing from my expierence

ok he is the real deal all of the info above is accurate but the most important one is missing!!!!

if your bike is a reed induced engine (i am 99% sure it is) this carb is not ment for it!!!
this carb is a pulse type carb it was desined for piston port engines! there is a way to bypass this but if you are not too handy do not do this yourself get a proffessional to do it! drill and tap the crank case as small as possible (to make sure the crankcase volume is not dramatically changed) also drill and tap the manifold between the carb and the reed block making sure it connects directly to the pulse port of the manifold going to the carb. then you must connect a tube from one to the other making sure there are no leaks.

this should fix your problem I have done this many time on my own bikes!

Alright man, that sounds about right cause I know for a fact that the engine has reeds! ANy cance I could get some more indepth instructions and maybe pics? There is a hole on the bottom of the intake manifold and the gasket was covering it untille i got the dremel out and cutomized the gasket to let something flow through there.

A few quick questions! Thanks again! Drill and Tap, Drill meaning just drill a hole, Ill probably use a rotary tool, Any clue what size? And what do you mean by Tap? Also Is the pulse port the small hole on the side that faces the intake manifold under the throttle? And tube size I'm wondering also the tube you mean must transport fuel from the small hole in the carb, (Pulse port I think) through the intake manifold into a tube and then into the crankcase?

Walbro carbs can be run on all types of motors... If you don't believe me contact Walbro for yourself and ask. Tell me if your 603 adapter has the pulse hole in it? And does it line up with the pulse hole in the carb??