I think my fuel filter was TOO BIG!

i have nothing to say

 

You have to get the air out of the filter so you don't cause a "vapor lock". I had the same problem at first start. It would run for a while and then die only to start a few minutes later. I got the air out of the filter and it never happened again.

 

Wierd! .. I ran one of those disposable clear plastic Fuel filters in My VW beetle for almost 30 years. I can't remember ever seeing the thing without a bit of air at the top of it. Shouldn't matter at all ..IF.. the thing is passing fuel. Likely yrs was either damaged (they are inexpensive) or clogged.

 

pvt +1
size will only make it harder to install.
as long as the fuel line and filter are below(gravity) the petcock.

 

thats what im going to do to mine since it wont run once i hit reserve...

wont run on reserve OR prime...

i had bought a small tapered filter but the nipple broke off when i was positioning it. the only other filter at the store was the larger (about the dia. of a quarter and about 1-1/4" long)...

it runs fine on a full tank but when the level gets low, look out. had to push the stupid thing last weekend...

im trying it next...

 

Our fuel systems (turbo excepted) are gravity fed. An air bubble trying to float back up the line will reduce flow a lot.

The large filters need to be full of fuel or they send that air bubble up the line. If you get the air bled out don't ever run out of gas or you'll have to bleed it again. If you get it mounted vertical, like Rick did, you'll be ok. He put his alongside the carburetors.

Dave, I had a heck of a time bleeding the filter on your Maxim. I suggest you replace it with a small filter. Chacal sells a real nice one with a 90 deg. elbow built in.

 

the first time i had alleged fuel flow issues on the seca, i filled the tank and the filter filled right up. there wasnt any 'bubble block' for lack of a better term...

both inlet and outlet were both covered with fuel when 'empty' but then like i said it was completely filled once i put fuel in the tank...

d

 

I had to get one with a 90 degree elbow in it for my bike to run

 

I guess this is why I bought clear fuel line.
and a clear filter.

"I can see clearly now that the air is gone"

 

I've had these problems also since putting my filter on an I believe these air bubbles need to be able to rise up into the tank freely to keep fuel flow going smoothly myself,,,,there has to be bubbles coming up from the float needle from time to time ,,,,,but I have no proof, clear line would be nice to see this working,,,,a bubble in the line would kill (weaken)the gravity feed until it burps..Dan

 

Exactly what I was experiencing.
I had left alot of hose so as not to crimp the line.
when I looked at the filter I discovered that the hose wiggled around and the filter now sat above the petcock so fuel wouldn't flow when low.

Something else I found out too, with the petcock being the low point in the line rust had gathered in the line and in the petcock were they connect.
I moved the petcock to prime and flushed the rust out of there, took the hose off and douched it out good.
In another filter thread someone asked if the filter should be mounted vertically?
I have a small clear cone shaped filter like this one, which appears to be backwards.

Anyway the shape of the filter allows sediment to collect in the bottom of the cone if it's mounted horizontally.
So I would not mount this type vertically.
I blew back through the filter and it had caught a bunch of rust.
Blew through the other way just to make sure it was cleaned out too.
Man am I glad I put this in the line.

 

I'm gonna revive this thread because I had an issue with my filter that had a inlet that was 90 degrees from the outlet, and it was catching the air bubble. Now I have a filter that has the inlet and outlet inline, and I noticed that it doesn't collect air bubbles, but that the amount of air changes in it from time to time.

If I let the bike sit for an hour or more with the petcock on ON, the filter will have a larger bubble. It will fill immediately if I put the petcock on PRI. I know that I could suspect the float seats, but I don't get any overflow, and I can see the bubble develop and disappear while riding (it'll disappear faster at a stop if I rev). I've rebuilt the petcock and have new fuel pipe orings.

Should I be suspecting my fuel lines (also new, but chewed up a little from taking them on and off for testing and tuning)? Is it normal to see a bubble flow up through the fuel line (I guess I'm asking if air displaces fuel in the line when the float needle opens, or if it's not supposed to)? I'm thinking this is a problem that could make me lean (and seems unusual) but I'm not sure.

 

An occasional bubble is fine; the filter doesn't necessarily have to be full as long as it's not trapping air.

Hound hit the nail on the head; to elaborate, the ENTIRE "run" of the line/filter/line has to be DOWNHILL. If you accidentally introduce a "trap" into it (a part of the line that is higher than the parts on either side of it) you can have problems.

 

I think I am experiencingu this problem. I have a very large filter on my bike, nearly 2 inches in diameter I would guess. I can run for long periods off turbo with no problem. On turbo, at interstate speeds the bike acts like it is out of gas after 3-5 miles. Once I slow down and work the throttle some fuel supply returns. Think I'll try a smaller filter.

 

If you put a muffin tin under the carbs, open the carb drains, and set the petcock to "PRI" (with the gas cap open, tank full) this would either completely remove trapped air, or - any remaining air would cause no harm, as you already out-flowed the motor's needs.

This won't work for "Slowboat"
Flow-test your petcock and gas cap vent, (off the bike), then pick thru your whole system, bench testing each part for flow.