Zx6r Carbs

[Andi]

Having got a set of a cheap carbs sold for spares due to the idle screw housing snapped off.

(fixed a nut and bolt in place with jb weld) Ive stripped and cleaned them and drilled 1.65mm

main jets.

The car started up and ran ok but petrol was weeing out of this brass hole (see picture).

Ive got duplicate carbs drilled to 1.8mm and dont have this problem.

I have a R1 fuel pump.

Anyone got any ideas before I redrill the jets?

 

Thanks

[Mitch]

air correction jet, think thats its name, sounds like theres either dirt in there or the float bowls need there heights checking.

when youre happy they run without problems i sugest you get them set up corectly on a rroad, you will be suprised in the dif, i know a great one in chester, put there addy on a post started by Simon, also happy client

 

 

HTH

Mitch

 

just reread your post, DONT drill out that jet, mine needed to go smaller, think there 125, mines now 100, if you do it will pop and ban on tickover and over run

[Andi]

I meant drill the main jets. I take it you dont have to drill the idle jets either?

Also couldnt really see how to adjust the floats.

[Mitch]

my idle jets were blocked with residue from the fuel, (varnish) and needed cleaning out with carb cleaner and a strong airline, no drilling!!, my mains are now (i think not 100%) 185. air corrector is 100.

idle screw is three and a half turns out.

dont know how to set float levels but sure someone will.

HTH

Mitch

[Mitch]

this help?

 

http://www.iwt.com.au/mikunicarb.htm

 

Mitch

[Guest Kano]

I would guess it's something to do with the float height or the float valve, take the bottom off the carb and check the valve or swap it with the carb nextdoor and see if it cures it.

[Guest robin]

i had exactly the same problem and it was the 'o' rings that hold the float valaves in place were perished allowing fuel past once the floats had reached full height. swapped out 'o' rings and problem instantly solved.

float height is adjusted by tweaking the little metal tab which acts on the valves but i dont know what the height should be or in what position but i'm sure that link in Mitch's post will.

robin

[Andi]

i had exactly the same problem and it was the 'o' rings that hold the float valaves in place were perished allowing fuel past once the floats had reached full height. swapped out 'o' rings and problem instantly solved.

float height is adjusted by tweaking the little metal tab which acts on the valves but i dont know what the height should be or in what position but i'm sure that link in Mitch's post will.

robin

 

 

 

Must admit Robin, hadnt seen any o rings when i cleaned them.

All the floats seemed at the same level.

Ill whip em off and have a closer look and compare them with the other set i have.

 

Cheers

[Guest Kano]

This might help find the O-rings.

 

[Guest SEgan]

My Carb did that when I first tried them, I put it down to dirt/varnish on the float valves. I ran some fuel rich in Redex through them, left it sat in them overnight and it has been fine since. (even with the Pinto mechanical fuel pump!)

[Guest robin]

the 'o' rings aren't that obvious as they hold the float valve in place in a recess in the carb body. you need to pull the vlave out to get to them to check.

robin

[Andi]

Cheers Robin,

Manged to get them out and yes the one is a little flat compared to the rest.

[Guest salty_monk]

O rings & varnish is a very common prob on carbs that have been sitting. Careful what you replace them with, they are a special material....

 

http://www.cycleorings.com/

 

Dan

[Guest robin]

mine practically fell out! definitely need fuel resistant 'o' rings to replace with.

robin

[Andi]

The reason I have been messing about between 2 sets of carbs is, the originals worked fine (1.8mm jets) but under load from low revs

particularly in 3rd and 4th the car would almost die. So to get good acceleration I had to keep the revs up. I thought I could live with this

due to the increase at the top end but it started to drive me nuts.

I tried the other set I had, re drilled those jets to 1.65mm, change the float O rings as suggested (which worked) but still had all sorts of

problems with these carbs, so i put the originals back on, swapped the bigger jets for the smaller ones and yesterday seemed to pick up

nicely, so I think problem cured.

Only problem last night was the carbs popped off the rubbers down a dark country track after the Leics meet.... A pet problem of mine that

seems to haunt me with bike carbs. Think i`ll clean them up and try glue in addition.