replaced fuel filter and now wont run unless i bypass petcoc By bobthetechguy (Read 630 times)

[bobthetechguy]

I replaced the stock chinese fuel filter with a duralast one. See picture.
My bike couldnt get enough fuel through that. I bypassed the petcock and connected the inlet side of filter straight to the line coming from tank. Lots of my vac lines look rotted so perhaps theres not enough vac pressure to operate it. Im going to get some 1/4 in tubing and replace it all.
imgur.com/hvYGwrX

[Bashan]

Bob that's a nice looking filter, I think you can take that off of the table as the problem. Now, vacuum, it opens and closes valves, end of story. Either your vac system is opening those valves or not. The only valve in question really is the gas tank petcock. Beyond that, the vac system does not pull gas in. Now if you have a vacuum fuel pump that could be a consideration but I don't think you do. So look over this link buddy and see what you think. If you ran the line right from the tank to carb there is no vacuum involved, it's pure gravity feed. Maybe I'm not picking up on what you're saying but tell me. Rich

[kz1000st]

Uh, no. A Duralast fuel filter is made to be used with a fuel pump banging away at 8 psi +. I heard years ago that you have to get a gravity feed filter like for a Briggs and Stratton lawn mower. I think if you put that crappy Chinese fuel filter to test my theory your problem will be gone. Long story, but I tried a car fuel filter on a bike one time and it starved out when I put it on reserve. Took it off, problem solved.

[Bashan]

Yes, you're correct, my bad. Sometimes they will work though. I ran this one for ages and it was designed for EFI also. I guess it just depends on the pressure the filter is spec'ed for.

Did you notice his filter is pointing the way to China?