Fuel Taps on 501fe

geoff · September 14th, 2004, 04:25 AM

Hi, my first post, to go with my first Berg....

Two questions.

1. Why does my bike have two fuel taps? Does one act as a reserve due to the shape of the tank?

2. Can I leave them or at least one of them set to ON all the time, or will it flood the engine?

thanks for any help, and for all the info I've already read.

Geoff

Taffy · September 14th, 2004, 04:17 PM

hello geoff and welcome to the fold. been a bit boring here lately but this week we've been playing silly buggers so there are one or two juicy threads for you to follow!

you need to put a reserve tube inside your fuel filters if you want a reserve otherwise you actually only have 'on' and 'off' and 'reserve' is only the same as 'on'.

also i have found it no problem to leave the fuel on on my keihin kitted bike.

follow my info sheet

here

Taffy

risky1 · November 22nd, 2004, 10:56 AM

In regards to the posted question "can you leave both fuel petcocks on" I would like to know also- I bought a 2002 FC470E and it runs fantastically (Except for being finicky at altitude on the starting but that will be in another post) This is my situation and question

Went for a ride sat. at about mile 46 my bike stalled like it ran out of fuel. I checked the tank and the right side was empty but the left side had about 3 inches of fuel left. I had the right side petcock open and the left side open. I scratched my head for a minute trying to figure out why it died when i still had fuel... so I figred i would try closing the right side (dont ask me why i just figred since there was no fuel in there it does not need to be opened) I kicked for a bit and finally the bike fired up with a really fast idle I rode about 100 yards and it sputtered, and popped and died. spent some time tring to start it and finaly it started again this time with a fast idle (did nothing to the carb) ran for about i minute and died again. so being that it ran great until i ran out of fuel in the right side i decided to put more fuel into it and see what happened. my buddies siphoned off some fuel from there exxon valdez Tanks mounted on their KTMs and i filled my bike up till the fuel was high enough to equalize on both sides of the tank. I opened both side of the tank and the bike fired first hit of the button it ran great until i could get back to the truck for more fuel (about 5 minutes) .

SOOO.... what gives- why would the bike not run off of the left side? I checked the left fuel line and it is clear- it sound like it was getting to much air when it was running off the left side-

should i just keep both sides open all the time- does it hurt anything?

JoeUSA · November 22nd, 2004, 01:17 PM

I keep both of mine open all the time I am riding.

Joe

Husabergler · November 22nd, 2004, 01:57 PM

Hi,
Try checking your gas cap vent. If it is plugged it will do exactly what
you described. otherwise if the fuel petcocks are not obstructed as you
have already tested. The engine should run until the fuel level in the float
bowl is too low to be picked up.
Also try checking filter screen at fuel inlet on carb. With low fuel
situation some water may have found its way into the fuel line. This could
also result in a situation that mirrors running out of fuel, by restricting
flow.

Husabergler · November 22nd, 2004, 02:44 PM

Geoff,
I was a little side tracked in my first post on this subject.
however to answer your first question. Two fuel petcocks
are used to assure constant fuel flow at all angles except up-
side down thats when your vent tube takes over. Secondly
yes you should keep both open all the time you are riding.
I shut mine off when not in use, why chance fuel leaking.
As long as needle and seat in carb. is in good condition and
float is working properly, leaving fuel on is o.k. too.

Regards,
Ryan

Splat · November 23rd, 2004, 03:59 PM

When my sons don't close the petcocks, I always get puddles on the trailer during the drive home. Always turn off the petcocks when finished riding.

I personally only open one at a time since there is no reserve tube. This leaves me with a large reserve on one side of the tank. I have never had an engine miss or stumble going up or down hill or leaning too long to either side.

risky1 · November 23rd, 2004, 08:27 PM

Originally Posted by Splat

When my sons don't close the petcocks, I always get puddles on the trailer during the drive home. Always turn off the petcocks when finished riding.

I personally only open one at a time since there is no reserve tube. This leaves me with a large reserve on one side of the tank. I have never had an engine miss or stumble going up or down hill or leaning too long to either side.

see that what concerns me. both petcocks were open but for some reason the rightside got sucked dry much faster than the left. When I did run out on the right side I shut it off and tried to run on the 3+ inches still left on the left side. bike just would not do it. it popped, sputtered, idled fast and died. once the bike was filled again it ran fine. i checked the line, the filter, the petcock, i cant figure it out.

logjump · November 24th, 2004, 06:12 AM

risky1,
It sounds to me like the fuel line that comes out of your left-side petcock is routed up and over the carb (or intake manifold) which is typical. If the line goes up 3 inches, that would explain the 3 inches of fuel remaining in the left tank. Follow? Gravity won't allow the fuel to go any further. This also explains why your right-side tank emptied first. Try re-routing the left fuel line so it goes under the intake manifold.

Logjump

risky1 · November 24th, 2004, 09:51 AM

Must have been telepathy or something

got on here to post my findings about the fuel line being routed OVER the carb and state "duh should have been the first thing i checked" and viola there was logjumps suggestion which was spot on to what the problem was. so anyway ran the bike this a.m. and ran it dry from the left side-no issues

thanks again.