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Stripping ZXR 400 L-model 32mm carbs a quick guide.

Time depends on how clean the carbs are, mine took me in total about 8 hours to do all 4, although this included all the sonication steps to clean everything. If you are just changing jets and needles expect ~15 minutes per carb to strip and the same to assemble.

Ok tools you will need:-
phillips screwdriver
thin screwdriver
pliers with a covering over the tips
3mm (i think) allen key
8mm (i think) socket/spanner

Dissassembly
First thing, check your carb internal diameter, they come in 30mm and 32mm versions, according to RedexRobB 30mm gives better midrange, 32mm gives better top end. These are 32mm:-


Ok mine came with the velocity stacks already removed, you will need to remove these and the plate on top to give:-


Now remove the (i think) vacuum cover, 4-screws:-


Take off the cover and remove the spring and the orange plastic bit:-


You can then take out the rubber slide holder/seal along with the jet needle, check the rubber boot for tearing/warping etc and replace if needed:-


Carefully remove the jet needle, you will have a small clip on one of the grooves and possible some small shims on top. I have 6 grooves, my clip is on #4 (from the top) and i have 3 shims on the needle. These were taken from a ram-air dynojetted race bike so DO NOT USE ANY OF THESE SETTINGS AS STOCK SETTINGS! Yes i know my nails need clipping and my cuticles are a mess girlfriend :-


Clean!:-


Next, flip the carb over and remove the 4 screws holding in the back of the fuel cover:-


Clean it! Also remove the fuel drain screw (allen key) and clean around there as well:-


Remove the screw in the top-right corner to free the orange fuel float:-


Then you can remove the assembly:-


Check the black plastic bit for damage, its what regulates fuel flow into the carb, if damaged replace:-


Remove the screw in the top-middle by the brass bit to gain access to another smaller fuel filter:-


Use your covered pliers to remove it:-


Onto the jets! This is the pilot jet, remove and clean:-


This comes in 2 parts, use a screw driver to remove the main jet, then use a socket/spanner to remove the brass bit that the main jet screws into. This brass tube is the needle jet holder...clean everything!:-


This is the pilot air screw, remove and clean. Once removed there should be 4 parts in this order, Screw - Spring - Metal ring - O-ring, make a note of how much this has been "screwed out" from fully screwed in. Manual states anything from 1.5 turns out to 2.5 turns out, turning it out richens the mixture:-


Put it all back together and it should be spanking clean like this:-


Put back on bike and give it a test with your new clean carbs!

I am not going to cover carb-tuning here, that will be for another guide.

One final point, i mentioned sonication, i used a sonication bath at work to clean everything. Brass/pure metal things can be cleaned in 100% acetone/carb cleaner, if you can get some heat in there do so, and sonicate for 15-30 mins changing the solution when it starts to go manky, repeat until the acetone remains clear. The main carb body i sonicated in water as i wasnt sure what acetone would do to some of the plastic parts...it tends to dissolve things fairly well. Then i washed the main body in 100% ethanol, making sure that i got it into all the brass bits to clean out any remaining traces of crud. I then used dry 100% nitrogen to remove all traces of the ethanol.

quality mate, nice little walk through that!

think maybe some settings need to be added - pilot jet turns etc...

i think that all the zxr 400 carbs are the same, manual lists all as CVK-D32...but they all have slightly different settings for things like pilot air jets...im only interested in cleaning, your best bet is to record what the base settings were for your carbs, then re-do these settings after cleaning

may have to add to this then if you dont mind?

where did you take your carbs to clean them mate?

will do, and i work as a doctor in a research institute so i have access to every chemical/solvent known in the western world and loads of equipment, plus we have a onsite workshop with 3 excellent guys in there, so i can even get stuff fabricated for a price

if you can get hold of a sonicator, you can probably buy acetone online, if not even something like meths/turps will be fine for brass parts, which all the jets are made of, you can also put a bit into the recesses that the jets screw into to, you have just gotta be careful with solvents and plastic/rubber.

one other note, always use distilled water, this you can definitely buy, halfords etc will sell it for use in radiators.

you can use this instead of acetone (but it wont be as good), just give everything a good blast of carb cleaner before hand and afterwards.

EDIT, failing that i might setup a sideline business, £20 for carb cleaning -p&p

banner001 wrote:one other note, always use distilled water, this you can definitely buy, halfords etc will sell it for use in radiators.

you can use this instead of acetone (but it wont be as good), just give everything a good blast of carb cleaner before hand and afterwards.

EDIT, failing that i might setup a sideline business, £20 for carb cleaning -p&p

do it was gona ask if i could send them to you lol

cool writeup, cheers!!!

no probs baz, ill finish the others at some point...

its definitely summat that the site needs, a proper detailed (with pictures) step-by-step guide to doing most/everything on the bike

Baz, is it worth sticking this at all??

Excellent These walk-through write-ups with pictures are enormously helpful when you come to tackle a job for the first time. Definitely what an owners' website should be all about.

It might be worth mentioning that there is a difference between a Phillips head and what the Japs use, although in most cases you can get away fine with using a Phillips screwdriver on Jap fasteners. The Japs actually use JIS headed fasteners. JIS= Japanese Industry Standard. They are not the same. Where you most frequently encounter problems in using a Phillips screwdriver on JIS fasteners is where the fastener is tight, the head is small and made of soft metal. This is often the case with carbs and electrical components. You can very easily chew up a JIS head this way.

JIS screwdrivers are not easily available but you can get them through a few places mail order. They are particularly popular with the model aircraft crowd as the small size of these things, and the fact they are covered in small, soft JIS fasteners means that a set of JIS screwdrivers is a must.

Tirpitz wrote:Excellent These walk-through write-ups with pictures are enormously helpful when you come to tackle a job for the first time. Definitely what an owners' website should be all about.

It might be worth mentioning that there is a difference between a Phillips head and what the Japs use, although in most cases you can get away fine with using a Phillips screwdriver on Jap fasteners. The Japs actually use JIS headed fasteners. JIS= Japanese Industry Standard. They are not the same. Where you most frequently encounter problems in using a Phillips screwdriver on JIS fasteners is where the fastener is tight, the head is small and made of soft metal. This is often the case with carbs and electrical components. You can very easily chew up a JIS head this way.

JIS screwdrivers are not easily available but you can get them through a few places mail order. They are particularly popular with the model aircraft crowd as the small size of these things, and the fact they are covered in small, soft JIS fasteners means that a set of JIS screwdrivers is a must.

...is something that looks to have happened a few times to both sets of carbs i have. might have to look for a JIS screwdriver then

and thanks

doc banner u ought to stop biting your nails mate

cookiesol wrote:doc banner u ought to stop biting your nails mate

yeah and the side of my fingers as well...get bored/stressed at work easy especially with long hours etc... still, not a bad writeup

brake rebuild will be up soon...kinda got a bit waylaid with work.

Good write up.

I've stripped my carbs 3-4 times and my bike is still running badly