Car fuel filter on KZ

Patton wrote:

If interested, Sudco lists its highest quality fuel hose in size 9/32” (7.5mm) I.D.

SUDCO Gray Fuel Hose with Red Stripe Kitaco brand fuel hose, gray with red stripe. Highest quality fuel hose available. This hose is found on many ATV/motocross/offroad Keihin carburetors. Sold pre-cut foot length or cut to length. Made in Japan.

Here's the link > sudco.com/fuel.html

Fwiw, I often dip end of new fuel line in a cup of boiling water for a few moments just before pressing it onto a fitting. Makes it much easier to adapt a smaller line onto a larger barb.

Good Luck!

Thanks. I'll try the 5/16" size since it will be about perfect. The original factory hose, that I have a little bit of, looks to be 8mm, and fits perfectly.

loudhvx wrote:

Those are the ones I find to have the problems. They are in the video above. If they work for you, great, but I'm done with them. I've tried them on several bikes, and they fail to prime on all of them. I've noticed they are sold under several brand names, and I've tried most of them.

The fuel supplier I use has final filters on the pumps which I'm sure helps but I've used one of the filters described in my KZ550 now for over 20,000 miles. It now shows some discolouration but no sign of fuel starvation. Have you blown through the filters to determine relative restriction new/used?

don't use the glass filters. I used to run those on my 71 240z and they would ALWAYS crack. I can't tell you how many headaches I had to chase down because that stupid thing cracked on me. They are NOT safe NOT all that effective, and are more hassle than they are worth. It would be an especially bad idea, considering all the vibrations on a motorcycle.

The one posted by Russ Jackson won't fit?

3/8 = 0.3750"

Interesting.

Have you tried a test where you have the fuel petcock on ON or RES, and after seeing that it won't flow like it's supposed to do on those positions, then take a longer vacuum hose, and suck on the vacuum line going the petcock. See if it will flow fuel then just as a test.

Paper fibers are supposed to swell up when wet. Maybe that's why it doesn't flow after sitting, without getting fuel on the paper again, or something like that???

Maybe trying the removal of the petcock diaphragm and spring, and test this again. Fuel should flow freely on all positions.

I take it you've checked the fuel screen on the petcock in the tank for any restrictions? I also have factory screen caps covering the fuel inlets to the float needle seats,but very fine dirt particles still pass into the bowls.


Needle Jet Inlet Screens

Will the fuel flow without the filter present?

I have several petcocks as well, and have seen the same thing you have Lou. Once I start the engine, and fuel gets to the filter, it will start to fill up. Sometimes on PRI I see no fuel in the filter, and after flicking it, it will flow a little.

Those paper filters filter very well, and clog in the process just like they are supposed to. The brass bead type will still allow very small dirt particles to get into the carb bowls, I know I've seen it when using a gas tank that the liner was peeling off from poor adhesion. I switched to the clear paper elements, just for that reason.


New and after 6000 miles

I have never had a fuel starvation issue on any of my GPz550's with the paper element, but have noticed it takes a little while to get fuel to flii up the carbs, when switching to RES while riding. This could be the reason.

Thanks for all your testing Lou.

In the video, it is on prime. I've taken that petcock apart a few times, and replaced all the rubber on it. The screen in the tank looks spotless. Without the filter, it flows like a monster... at least 3 to 5 times as much as when the paper filter is actually flowing.

I agree, the paper filters filter very well. The carb bowls are always pretty clean when I inspect them, (about 3 or 4 times in the last year while doing jet changes). I just think they need a little positive pressure to work right, not just gravity.

It happens even when the filters are pretty new. I start to notice problems after a few weeks.

I'm going try sintered bronze filters. I bought a case of bronze elements for a chevy for next to nothing. I'll try one of them if I get a chance. I'm not holding my breath on those, though.

JMKZHI wrote:

The one posted by Russ Jackson won't fit?

3/8 = 0.3750"

I guess I will have to take it off then seeing as it doesn't fit. I am using it on a set of 29s and it works fine. I had used ones similar to the ones posted but they clogged and did not flow enough for the smoothbores. It was a totally different bike after I changed over...Russ

Russ Jackson wrote:

JMKZHI wrote:

The one posted by Russ Jackson won't fit?

3/8 = 0.3750"

I guess I will have to take it off then seeing as it doesn't fit. I am using it on a set of 29s and it works fine. I had used ones similar to the ones posted but they clogged and did not flow enough for the smoothbores. It was a totally different bike after I changed over...Russ

Hi Russ,
I think he was asking if the one you posted won't fit on my bike. Mine needs 5/16" inlet/outlet.

On my bike, the pipes are 5/16", but obviously the barbs on the ends of the pipes are larger than that. I'm pretty sure I could force the 5/16" hose onto the 3/8" fittings on the filter, but I should be able to find a 5/16 version, I'm sure.

JMKZHI wrote:

The one posted by Russ Jackson won't fit?

3/8 = 0.3750"

I believe I could make it fit, but I'm pretty sure Ive seen 5/16" versions like that.

Got it. I just know after using plastic paper ones at first. And I kept pulling my carbs and cleaning out jets from crappy gas all the time.I was in a Jegs store and saw that one and bought it. It has been over 4000 miles since I had a carb problem. I am kind of old school and would never check the size of the outlet or inlet. Put a clamp on it tighten it and fire it up. My carbs love fuel and if it isnt flowing well it loses a ton of power at high rpms. This solved my problem and seemed to fit very snug on the carb inlet. I actually have a dificult time pulling it off and I dont use a clamp at the carb inlet point...Russ

loudhvx wrote:

bountyhunter wrote:

loudhvx wrote:

I wish I could get a 5/16" sintered bronze filter in a clear container, but they are pretty scarce. I've seen some in aluminum containers, but they are a little too big to go where I want it.

These might fit.

cgi.ebay.com/ebaymotors/CHROME-FUEL-GAS-...mQQitemZ390072683108


Here's a clear one:

www.parkeryamaha.com/visufilterhigh-flow...lter516linesize.aspx

Thanks, those both look good. I've been looking at those aluminum cans with removable sintered elements. I thought they might be too big, but it's worth a try at this point. I hadn't seen that clear one before.

I have the aluminum can with removable filter, looks and works great so far.. Hot as hell out if i get out in the next few minutes ill take a pic for ya

Here it is..