float valve screens

[screamin deal]

Taking my needle seats apart to clean and may have smooshed my screens a little. Anyone know where I can find these . All the rebuild kits I've looked at do not have these parts in em.
Thanks in advance

[Ivan]

the old needle and seats I took out of my carbs didn't even have them. I would say that the screens in the tank and any additional filtration would far surpass the benefit of the needle and seat screens.

[wingnut]

There is a guy on the XJ site that sells just about anything having to do with carbs used on old Yamahas. You can look here

http://www.xjbikes.com/Forums/viewtopic/t=14561.html

I think its in section C

[bikerphil]

screens

Taking my needle seats apart to clean and may have smooshed my screens a little. Anyone know where I can find these . All the rebuild kits I've looked at do not have these parts in em.
Thanks in advance

It's a good idea if possible to have those screens in place to keep any junk out of the needle and seat. It's OK if they are a bit squished, but if they are in too rough shape, Bikebandit.com got 'em for $8.49 ea.

[skids]

Ditto. Replace the fuel lines to ensure you don't get any rubber bits from old fuel line that the in-line filter does not catch. Toss out all of those cute little screens.

the old needle and seats I took out of my carbs didn't even have them. I would say that the screens in the tank and any additional filtration would far surpass the benefit of the needle and seat screens.

[prometheus578]

Not all makes of bikes have float seat screens.
Luckily, ours do.
Leave 'em in.
Those screens on the petcocks do fall out... especially when people shove a garden hose into the tank to siphon out gas.
Then, you get rust particles and chunks of crap coming down the line. Float seat screens prevent that stuff from wedging the float needle open.
Yeah, yeah, yeah.. I know... but everybody doesn't have in-line filters.

[DGXSER]

Do not remove them

I just opened my carbs up, got them stripped down, (well almost all the way, fricken mixture screw!!) anyway, the dirtiest spot in the entire carbs is the inlets at those screens. Definitely some small black bits in there. They have all new fuel lines now, but it would seem it was a problem at some time. Just got the bike a month ago. Also just added in line filters.

So I would NOT suggest leaving those screens out based upon what I see in my carbs.

[screamin deal]

Great info one and all I will keep screens in and see if I can repair , If not replacing won't be awful waiting 3 days for delivery. I have plenty to keep me busy while waiting. Thanks for all of the great responses.

Merry Christmas to all !

[randy]

Z1 enterprises has the screens for $3.74 each. Search keyword 'mikuni'

http://www.z1enterprises.com/

[boyat68]

screamin deal:

Those little screens come off by prying the plastic band down a bit. Then you can use a pencil eraser end to smoosh them back out to an oval configuration. They are fine mesh brass and take a fair amount of smooshing, and as everyone else has said they do catch the particles that will cock the needle valve open. The replacements when you buy from some of the suppliers the seats and valve assemblies in a kit have aluminum screens if you can find them.

[oldyam80sg]

Those little screens all gummed up was the main culprit on my #2 carb not working.Exhaust pipe was lukewarm at best and when i saw all the crap in there ,i knew i was on to something.Cleaned them using carb cleaner and compressed air and #2 carb was happy again.If you would have seen what those screens caught,you would also leave them in there.

[Ivan]

So if the screens catch so much junk, then why is it that several million carburetors over the years function fine without them?

These are the only carbs I have ever seen with such a device, admittedly I have not done that much with motorcycles, but I have rebuilt a couple thousand automotive carbs.

Methinks that the junk you see in the screens should have been caught long before the needle with proper filtration. Beyond that, any junk that gets flushed through the needle is probably going to end up settling to the bottom of the bowl where it won't hurt anything, unless you roll the bike, in which case there are other problems to attend to. Personally, I would rather crack the bowl drains once or twice a year and let the junk flush out than remove the carbs, take the needle and seat out and clean that screen.

Yes they are old bikes, and may get junk in them, but for $2.95 you can get a paper filter that will catch more junk than a screen ever will, and never need to worry about the screens. I have no idea why that is such an impasse for some people.

[DGXSER]

Ivan,

For me it is not an impass as much just my opinion. We all know how everyone has one, some just stink worse than others.

In my little mind, if there is a safety net to protect junk from getting to the rings and valves in my engine, or even those little holes in my jets that can cause me the headaches I have had so far, especially one that was put in from the factory, then I like the added insurance. Seeing what was behind them in my carbs, just gives me more reason to feel they are not extraneous. I did remove the octy, so I am not that maniacal about it.

Just opinions, how safe is safe enough for you. He asked, we gave information to let him make an informed decision of his own, just as you did.

[bikerphil]

screens

my carbs didn't even have them.

If you never had them, you don't know what yer missin'.

[fredintoon]

I kept my old ones

When I replaced all 4 float needles & seats on my XS11SG the new seats had the grooves for the dome filters but they didn't come with screens on them.
So I carefully pried off the existing ones and snapped them onto the new seats.
No such thing as too much filtration, right?
Another thing about the in-tank filter towers falling off the gas taps.
Not only is the gas not filtered, you got no reserve neither.
If you ignore the gas gage or the red light or if they aren't working you rely on
having to switch to reserve to know to look for the next gas pump.
If there is no reserve, the XS11 is a real heavy bike to push.