mixture help !! cv34 carbs.

Some CV carbs are designed with an enrichener circuit which adds fuel, while others are designed with a true choke that restricts air.

An enrichener circuit has passages built inside the carb.

A true choke consists of an adjustable flap that governs air intake into the carb throat.

It's the enrichener type that properly functions only when the throttle is fully closed.

Good Fortune!

True "TexasKZ" heres a pic of the part to swap with number 4 and see if the cylinder you install it in starts to turn black. Process of elimination has save3d me lots of money through the years Generally all will wear out evenly but if you have a needle that wasnt spinning like it should, it could have worn it on the intake side. The needle jets do not turn and wear in one place only, the jet needles do spin and usually wear more evenly all the way around. Its good to eliminate worn needle jets before you spend an eternity getting pissed off.

hi again !!
well cheers for all your help ( all of you )
i did misunderstand the " needles" - did not pick up on the jet bit !! :blink: was reading too fast --however i think you have hit the nail on the head
i changed number 2 diaphragm with needle over to number 4 .
now number 2 plug is still good but number 4 is better than it was ( not so much soot ) ..
i can conclude that it must be mainly wear on the needle jets !!
i have sorted out the "popping" on throttle down as well
i altered mixture screws to 2 and1/4 turns ..
however folks this bike is running better than bikes a few years old :woohoo: :woohoo:
it now ticks over at 1500 rpm and runs so sweet it is unreal..
i can say hand on heart if you came to look/purchase it and test run it you buy it there and then !!
the only way you would know it was a bit rich is by removing the plugs.
even with a hand on rear of exhaust ,there is no smell of rich fuel or any type of smoke !! :lol:
on a final note for now-- have checked my manual and it says needle jet not available though -- do any of you guys have a part number or supplier ?? this would fit the last piece of the jigsaw xx
cheers again
martin

hi rcook52459
thats ok about the thread
it was a good idea since we seem to have similar problems :ohmy:
if we all on one thread it may help to get us all 100% running

have you looked at bikebandit.com for carb parts for your bike?

You should be able to find aftermarket needle jets, Call Sudco also, they might be able to help and put a call into your local shop and see if the company K&L makes anything for them.
Last but not least, make a call to Kawasaki Heavy Industries and explain the situation.
I remember buying them for a Yamaha Fazer one time and Yamaha showed them as discontinued.

hi again folks>>
well i spent all day on the net serching for needle jets :ohmy:
it seems if you have mikuni - then there is tons of them :blink:
however these cv34s seem to be a big fat no.. it is the same with the number 35 pilot jet, they can not be found anywhere??
iv tried sudco,bike bandit,k&l,jets r us,z enterprizes etc etc etc -- and no one has them ( not sure they were ever available - manual says n/a
im in the uk and we cant even get primary mains(62) -- i had to send of to powerbarn ..
all i can say though is a BIG THANK YOU..to all you guys and for patton etc for having this wonderfull site for info
should anyone find these jets or if anyone has replaced them for a different part number,please let us know
as for now iv just done thirty miles and checked plugs , 3 of them are a little sooty and one is spot on
bike is running superb , so guess il just ride on !!!
-- now , what can i take apart next :woohoo: :woohoo: lol lol xx

Am not convinced that worn needle jets are causing the mixture issues.

Regarding the rapid accumulation of soot on a spark plug, the reported history consistently refers to setting float heights, when float height isn't the critical objective.

Setting a float height to some precisely measured position while the carb is partially disassembled upside down on the work bench provides a false sense of security, imo.

The critical objective is actual fuel level inside the float bowl when the carbs are fully assembled and in level position, as when on the bike. This is known as the service fuel level, which is determined exclusively by the clear tube test.

It is the fuel level -- NOT some measured float height -- that influences air/fuel mixture.
Regardless of the measured float height, a too high fuel level will produce a mixture rich enough to rapidly soot the spark plug.

In a bank of carbs with perfect fuel levels, it's not uncommon for all the float heights to be different, and with none of the float heights exactly meeting the upside down dry measured spec shown in the manual.

Where the fuel level is seriously out of whack, adjusting the float height to a measured spec may achieve a preliminary position at least somewhere in the ballpark. To be followed up with the clear tube test and properly setting the fuel level.

Once the fuel level is correctly set within specs (as confirmed by the clear tube test), the float height is then "correct," regardless of what its upside down measurement might happen to be.

In a perfect world, with all new parts, setting the specified float height would probably result in coming pretty close to achieving the correct fuel level as measured by the clear tube test. But the parts in our old girls aren't new and aren't perfect.

When reported history includes fuel level being within specs as confirmed by the clear tube test, it's then okay to quit worrying about float heights.

Good Fortune!

When bad needle jets cause the issue, its because the hole is worn to much and it starts to draw fuel from the mains as well as the pilots jets when it should be only drawing from the pilot jet.. Many times when its this way, it can idle nic but as soon as you start to open throttle its getting too much.Lowering float level might help a little, but...

make sure u got 12 volts at your coils. i found this and seemed to work. www.wgcarbs.com//index.php?option=com_co...view&id=12&Itemid=26

hi,,ok iv checked float levels with the " clear tube method "
i have set them slightly lower than recommended and i still get 3 sooty plugs ( bike still runs great )
i think next to eliminate the problem i will swap the "needle jet " over, and see if the other plug gets sooty ( as sugested by old skool z )
cheers rcook52459-- article was intresting about coil voltage ( think patton did also mention this before )..,i will test this and see what it says .. ( i dont think this is the problem , since i have 2 coils running 4 plugs -- 1 plug is good ,so at least one coil must be getting correct voltage ) i also have a new battery ..
will let you all know results when i can ..
cheers lads ..

hi again..
well it looks like the problem is worn needle jets.. :huh:
ok this is what i have done since my last post ---
checked voltage going to coil -- it was only showing 10.9 and 11.0 volts !!
i followed rcooks link and wired a relay to the battery ..
this gave me a full 12volt plus . i then ran bike for 40 miles and checked plugs --
--black as before :dry: :dry:
i then checked and cleaned all the needle jet holders ( that brass tube with lots of tiny holes in it :laugh: ),i swapped number 2 ( good plug ) holder for number 4 ( real sooty plug )...
took it out for another 20 miles --- same results .....
i then tried to move the jet needles side to side from below the carb ,with all the holders removed -- we have some play going on !!!
i stripped one of the carbs and it appears that the actual "needle jet" on the cv34 are "pressed" into the carb itself and can not be removed... :huh:
this would explain why the manual gives no size and states not available
i think the only solution is more carbs !! (mikuni for me,at least you can get parts)
there is only one other thing left that i did not check -- valve clearance !!
i do not want to take cover off at the moment as the bike runs sweet and has no rattles or problems etc from the head .. as well as the fact there are no tell tale signs of the valves having incorrect settings
should i try more carbs and get same result , then the problem would be valves,
if anyone has any feedback please post it up !!
thanks so far for all your help ..
cheers
martin