Go kart pulse pump

[Cesar]

I recently put a pulse pump on my gx200 engine at first it worked well with a few pulls the gasoline would get sucked up and would work fine but now it doesn't the fuel up I can see the fuel sitting in the line about 5 inches from reaching the pump but it never moves up it just gets pushed down and then up to the original position. Whats wrong?

 

[crazykart]

I'll take a stab at the easiest answer here. Is your gas tank vented or sealed?

If it's sealed could be that there is too.much pressure in the tank now, and it's pulling the gas back toward the tank, then the pump pulses and sucks it back up to where it was before in the line.

Easy way to know, take the gas cap off and try again. Of it works right then you need to get a vented cap. If not idk.

 

[Cesar]

Yeah that worked thanks! When I took the gas cap off it went down then I put the gas cap back on gave it a few pulls and it went up thanks a lot

 

[Cesar]

Can I make my gas cap ventilated or do you have to buy one?

 

[chancer]

Buy one

 

[crazykart]

Yes buy one. You don't want to just put a hole in it as gas will just spill out, it needs to have a one way check valve. When it reaches a certain pressure the valve draws in air.

 

[Justin9]

You shouldn't pulse the fuel pump from the breather on the valve cover, you need to drill a second hole and tap it for a nipple below the check valve that is installed in the valve cover... if you check out 4cycle, you can find pics how to do this properly.. I use to race clones for several years, you need that stock breather to be open or to a catch can...

Here is a link to BMI karts with a pic... http://www.bmikarts.com/Over-Head-Valve-Cover-with-Fuel-Pump-Pulse-Fitting-_p_65.html

see how they have added the brass nipple there and its real low, that to get it below the check valve in the valve cover... if you have a drill bit around 1/2" and can buy a brass nipple, you can do it yourself...

 

[chancer]

Besides BMI selling you that breather. AGK has a "how to" for instlling a fuel pump and their best choices and luck with different pulse locations. https://www.affordablegokarts.com/fuel-pump-setup.php

 

[Cesar]

Thank you all for the help I'll be sure to install a new spot for my pulse

 

[BirdFanatic]

I have one that no one has been able to answer i rebuilt the carb so thats not the problem either is the fuel pump my motor has dual pulse fittings every time i pull the cord it starts then bogs out then i pull it a few more times and it completely fills with gas .
Cesar id drill a tiny hole in the top of the cap to vent .That is just me though .

 

[Half-breeder]

A. u NEED a non collapsable tube from the valve cover to the pump.
B. a return line from the out of the pump to the tank is recommended.
C. an inline filter is recommeded "to" the pump from the tank.
D. on a norm the valve cover tap is on the other side of the inner diaphragm.


... just my .02.

 

[BirdFanatic]

They ran on fuel line fron one piece on the carb to the pulse then another from another pulse fitting to the fitting on the pump then.They ran a hose to the fuel inlet on the tilly carb id have to send you a pic its a weird set up for a Tillotson HL315A