Does anyone know what this is? It was spliced into the fuel line running from the petcock to the carbs. I took it out when replacing the line because I don't think it's stock and it looked old and dirty, so I figured I'd be better off without it. Is it some kind of filter for the gas?

Yes and You will have problems if you do not replace it.

I had more problems with my fuel filter.  It would either get air locked or vapor locked all the time.  I had to bypass it to get home more than once.  I figured I can pop out the carbs and clean them in 2 hours once a year, so why the hell not.  Maybe I just had a crappy type of filter, so I should get another kind and try it.

Mine was metal.  At least with the glass kind you can see if engine heat is boiling your fuel.  I'd leave it in if it doesn't cause you problems, because clean fuel is better than dirty fuel.

I havent got one .. didnt even know they had them , and ive not had a single problem

Well.. Seeing that the PO put that one on there, there may be some underlying tank problems (AKA rust). I would replace it with a cheap cone shaped one available at all bike shops for about $4  I have one on my gs  and I have no trouble 

Quote from: Jay_wolf on October 01, 2007, 02:22:24 PM
didnt even know they had them

They're not stock.  You have to cut the fuel line and add it.

Using fuel filters with the crappy stock gs petcock was a PITA. I gave up after trying 3 different filters. Now I keep the tank FULL and dump in some SeaFoam when I remember.

FULL tank = no or very little condensation to make rust

You can always pull the carbs when they get nasty, or just drain it all.

Interesting.  So someone other than me had a bad experience with fuel filters.  Others say it's great.  I wonder what the difference is.

The factory fuel filter is inside the tank and part of the shut off valve mounted on the bottom of the tank.  There shouldn't be much if any debris going into the petcock.  It's an expensive piece to replace though.

This second filter seems redundant and an added potential for vapor lock.  I'd make sure it's got plenty of air circulating around it to keep it cool.

BH

Quote from: scottpA_GS on October 01, 2007, 02:58:36 PM
Well.. Seeing that the PO put that one on there, there may be some underlying tank problems (AKA rust). I would replace it with a cheap cone shaped one available at all bike shops for about $4  I have one on my gs  and I have no trouble 

I have spent too much time pulling carbs to clean them only to have another issue pop up because the carbs have been apart. Carbs are temperamental and I take every precaution to keep my bike up and running. The screen in the tank is a joke and that is the reason so many people have fuel related problems. Rust and garbage comes down the fuel line and causes friction that the petcock diaphragm has to overcome sooner or later it fails or works erratically because of buildup. If you think you don't need fuel filters just buy a clear one like in the picture and run it for a year and you will never go back. Looking at the picture you can see how rusted and nasty the filter is (it started out white) all that is shaZam! that didn't make it into the carbs/engine. BTW you can pic up these filters at Autozone. I put fuel filters on ever bike I have ever had and never had a problem with vapor lock. I have never used a metal filter though i use the plastic semi-transparent type and have always insured they are up away from the motor. My gs has two filters on the lines coming from the tank one for the "on" and one for the "reserve" before the petcock to insure none of the crap ruins the new petcock. I had to replace the prevous petcock it was caked up with crap from the tank and beyond cleaning.

It started out white? Hmm, yeah, I think I'll replace it. Thanks for the advice.

Yes it looks like the ones that they sell at autozone. All the ones like that I have seen are bright white. You will see what I mean.

I bought one of the large one like you have photoed... I could NEVER get it to stop leaking  I went with the small cheap ones instead 

I have the double filter set up as well(one reserve and one main) and haven't had any problems with fuel starvation although I ride on prime all the time.

Normal gasoline with stain most anything. The yellowing has little to nothing to do with rust. The only gasoline (if you can still find it) that does not stain, is Amoco premium and it is clear. That seemed to have changed when BP bought them.