743 fuel primer bulb

[ddsprint]

Looking for some input here, put a new fuel pump on, primer bulb collapses, put a new in tank line and a one way screen in tank, ran better although with about 30 min use, primer bulb collapses, by pass fuel filter and samething, so what is it that I'm missing in this puzzle here, All inputs would be greatly appreciated, thanx,

 

[tubby's repair]

Sounds like you need a new cap. Vent is pluged. Run machine till primer collapses then loosen cap and see if it expands back out. Wes

 

[ddsprint]

Sounds like you need a new cap. Vent is pluged. Run machine till primer collapses then loosen cap and see if it expands back out. Wes

it is a new cap as of last summer and it is doing it's job, thanx, So when is a primer fuel ball shot, last one sucked tight time and time again and put one in that had in tool box, still has suction so put it in and it is doing the same thing,

 

[Fishfiles]

it is a new cap as of last summer and it is doing it's job, thanx, So when is a primer fuel ball shot, last one sucked tight time and time again and put one in that had in tool box, still has suction so put it in and it is doing the same thing,

most probable cause is , you shouldn't have put the screen back on the end of the tube and it is clogged up again , do away with the screen ---------------------- other things I seen that colapse a bulb would be motor mounts bad and oil pan is smashing the fuel line , trash in the inlet side check ball of the prime bulb , pieces of detereorated fuel tubing stuck in the 90 degree fitting coming out the tank and a flap of rubber from the inside the fuel hose blocking the flow , wrong fuel cap not venting --------------run a seperate fuel tank or gallon jug to the primer bulb and if it runs no problem it's between the bulb and the tank

 

[mrfixitpaul]

most probable cause is , you shouldn't have put the screen back on the end of the tube and it is clogged up again , do away with the screen ---------------------- other things I seen that colapse a bulb would be motor mounts bad and oil pan is smashing the fuel line , trash in the inlet side check ball of the prime bulb , pieces of detereorated fuel tubing stuck in the 90 degree fitting coming out the tank and a flap of rubber from the inside the fuel hose blocking the flow , wrong fuel cap not venting --------------run a seperate fuel tank or gallon jug to the primer bulb and if it runs no problem it's between the bulb and the tank

Also check that the fuel shutoff petcock is fully open, and remove the lines at the valve to make sure there is no debris in it.

 

[Fishfiles]

Also check that the fuel shutoff petcock is fully open, and remove the lines at the valve to make sure there is no debris in it.

After revisiting this thread I relized that it is a 743 and not a 753 that we are talking about , the possible causes for your problem I listed are ok except to delete the smashed fuel line from motor mount problem as 43 didn't have that problem , I realize now you have the old style Lucas /Cav filter and bowl set up , that freaky looking on/off valve mentioned haas a very small passage way and does clogg up , if the machine were mine I would change the filter head to one that uses a screw on filter even if I wasn't having a problem as those filter can cause problems with air leaks and are messy to change out --------they make an adaptor that screws on to the original filter head and accepts a fuel water seperator filter , they use to sell for about $40 but that was quite a few years back , a Lucas Cav dealer should be able to get one for you

 

[Rich M-37]

After revisiting this thread I relized that it is a 743 and not a 753 that we are talking about , the possible causes for your problem I listed are ok except to delete the smashed fuel line from motor mount problem as 43 didn't have that problem , I realize now you have the old style Lucas /Cav filter and bowl set up , that freaky looking on/off valve mentioned haas a very small passage way and does clogg up , if the machine were mine I would change the filter head to one that uses a screw on filter even if I wasn't having a problem as those filter can cause problems with air leaks and are messy to change out --------they make an adaptor that screws on to the original filter head and accepts a fuel water seperator filter , they use to sell for about $40 but that was quite a few years back , a Lucas Cav dealer should be able to get one for you

I had this problem on my 873, I cut my pickup tube back 1/2 inch. My tube did fall in to the tank and I could not retrieve it. I cleaned out that little filter about 3 times before shorting the tube. I also drained the fuel tank, Inever got any large amounts of trash out of the tank either. Rich M-37