Quick Carby Diagnosis

[Seifer]

Ok guys i've just torn my carbs apart, replaced the t-joint seals and reassembled. Ive also made sure floats etc are in correctly.
Now only two cylinders are running, 1&2. After a bit of diagnosis I opened up the emptying bolt from carbies 3&4. Completely empty. THe fuel filter is full and the hose looks like its under a little suction ie very slightly oval shaped, not round between the filter and carb.
Before I go to tear them apart, what have I missed that would stop the fuel getting into both of these carbs?

Given that it's 2 carbs on the same side I would think that the problem is in the lines, more so than the float assembly. Remove the inline fuel filter and check the tap filter on the inside of the tank for restricted flow, then see how they go. With the bike on the side stand, Cyls 1 & 2 will naturally fill before 3 & 4 (I take it that the fuel line connects between 2 & 3 carbies). try standing the bike upright with the tap on prime for 10 minutes, then check the drain plugs

If still no joy Pull'em off and blow through the lines to verify that the internal and external lines are clear. Have you checked that the floats and associated needle are moving correctly? Give the Tabs on the floats a bit of a touch with fine sand paper to ensure the needles aren't catching on them.

[Deano]

i am with chalky mate

sounds like you are only getting fuel out of 1 of the 2 tap outlets.

[alfiestorm]

Or it could be your piston return springs on 3/4 have snapped so no vacum or suction to pull fuel through :D

I reckon the fix would be to fit a yoshimura diesel carb :D:D

Except that venturi operates on the fuel after it fills the bowls.

I reckon he should borrow boosters (?) new pump and just force that petrol shit through, that'll <s>fuck</s> fix it

:D

[Seifer]

Well i just swapped it with another fuel tap I had lying around and that seems to have sorted the problem. Now the original leak is back. It's dripping from the mixture screw so i'm guessing thats a float problem? I just wish these carbies'd work. Its the only thing stopping me from riding the bike i've spent the last 6 months building! Again i'll have to take the carbies off and take another look.

Is that with engine running or stopped?

Check that the needle tips aren't damaged, and that they slide smoothly when in place.

[Seifer]

Engine stopped. The slide wouldnt slide back as far as the other 3 but I couldnt work out what was blocking it. Still as i said this is with engine off and the tank set to prime. Any one got a new set of GSXR 1100 carbs, i'm sick of these ones. They were fine till I pulled the engine apart. I didnt even touch the carbs and they are fucked. I'll have a closer look at teh floats and seats.

Some carbs will naturally flood their carbs when sitting with the tap on prime. Try it with the tap set to on and the engine running, it could well be fine.
GPz900's have been known to flood number one cylinder when on the side stand with the tap on prime, hit the starter button and the engine tries to compress the un-aerated fuel, BANG, number one has a fucked conrod.

[Hillsy]

Hey Seifer - are you running a fuel filter? If not, get one - a cardboard element car one if you can fit it in (they are bigger and filter better).

You'll be surprised how little crap you need in your fuel lines to foul float valves and jets.