carbitooter trouble

[tongham runfold]

have a used walboro 668 carb
could not get the primer bulb to fill
so replaced all gaskets and pump diaphragm with new
still can't get bulb to fill
any ideas anyone?
:no:

 

[kryptonite5b]

make sure your fuel lines are going the right way. the line that has your tank clunk goes to the back of the carb and the return goes closest to the primer bulb

 

[tongham runfold]

yeah got that sorted
but still got problems
:no:

 

[kryptonite5b]

still not priming? check these
-clogged clunk? if it sat for a while(long while) oil could have clogged clunk
-cracked fuel line? that has to be a big crack, but could happen if the lines are dry and hard(old)
-cracked primer bulb? i think that you would see that.
just go thru the process of ilimanation.. pull the clunk off, pull all the lines out of the tank, try to get one line to suck fuel thru a cup or something. it is a pretty simply process. and its not going to be anything major. and double check wich way your lines are going. they are easy to swap. if you think they are going the right way, swap them anyway..you can also check the filter in the carb. but i highly doubt that being as issue

 

[Timmahh]

if the primer bulb wont fill, i would susspect the gas line is craked or broken. i would pull the link off the carb and out of the tank and inspect it very well. also check the hose nipple on the carb. ive seen those crack too b4.

now are you getting ANY gas into the bulb? they basically don't fill up (but should get 2/3rds the way full or so).

 

[Clubin]

Maybe the fuel line with the clunk on it got pulled on a little and it is not in the fuel?

 

[tongham runfold]

engine on my bench fuel line into petrol (new line)
primer bulb ok (sticks to my forehead no problem)
still got problem
getting a small amount of fuel, enough to cover bottom of bowl.....just
anyone know where i could find exploded or tech type drawing for carb
and whats the difference between a 603 and a 668

 

[dc2 man]

Try this

check where the pipes connect to the carb,most lightly gone looser from putting on/taking off,check them, i guarantee if you cut your pipes around 6-7inches back and rejoin them you wont be drawing any more air

OK just read that you replaced fuel line,still check that the connection to the carb is secure,check your filter in the fuel tank.

NOW I CAN GUARANTEE this will work!! REMOVE your fuel tank vent(where two pipes enter the tank,puch it back in the tank and make sure secure,repeat this a few times and each time prime for fuel,it is drawing air at the vent on the tank,go and check that and see how you get on,as your priming keep presure on the fuel tank rubber vent,(the rubber fitting where two fuel lines enter tank)

try it.....

let me know.

 

[Clubin]

engine on my bench fuel line into petrol (new line)
primer bulb ok (sticks to my forehead no problem)
still got problem
getting a small amount of fuel, enough to cover bottom of bowl.....just

With the lines off the carb, prime the bulb, the top is out and the bottom is in, you should feel somthing. If all else fails just install a new carb. They are cheap enough.

 

[dc2 man]

Check this first!

check where the pipes connect to the carb,most lightly gone looser from putting on/taking

now i can guarantee this will work!! Remove your fuel tank vent(where two pipes enter the tank,puch it back in the tank and make sure secure,repeat this a few times and each time prime for fuel,it is drawing air at the vent on the tank,go and check that and see how you get on,as your priming keep presure on the fuel tank rubber vent,(the rubber fitting where two fuel lines enter tank)

try it.....

Let me know.

check this and see first!!

 

[Bigger the Better]

anyone know where i could find exploded or tech type drawing for carb
and whats the difference between a 603 and a 668

Here is a tech how to - How-to

According to DDM:

There are a few very minor differences. The external throttle linkage is slightly different on the 668, and one of the fuel pass-through areas inside the carb is .003 larger on the 668.

Performance-wise they are essentially identical.

Exploded View: 668 Exploded View

 

[rogerrally]

my carb is apart at the moment as im fiddling about with inlet pipe angles( thanks to the guys on here), so if you needed to look to compare/ swap, id be happy to help, only live 5 miles away, workshop in Wanborough, live in Farnborough, was in Badshot lee yesterday watching the electrics, but too quiet for my liking!