www.zxrworld.co.uk

hi all. still having crap with me bike. Wehn the bike starts it revs perfectly and sounds sweet. Stop the bike, try to start it and it wont. back fires once after sometime trying to start it, then seems to get hydro lock as when turning over it seems that there is too much fuel in the combustion chamber.

my question is how do i know that the fuel needle valve is closing properly and is not allowing fuel to leak into the chamber when the bike isnt running? is there an easy way to find out? easy-ish i should say

take the plugs out and se what state they are in?

If you wanna check the float levels then use a piece of clear tubing on the drain nipple and unscrew the drain screw. Hold the tube up and there is a mark on the side of the carbs (rhs) that tell you where the float level is sitting at.

You could also run the bike with the air box off and check that the needles are lowering all the way by looking through.

cheers rob. the first part of that is a good idea. the second has missed my potential prob. its the fuel level in the carb bowls and if the cut off valve is working that i need to know.

Oh you mean the needle float valve? Thats a 'take apart' job that one.

yea thats the one mate. how do i know if fuel is being cut off?

I dont think you do.

I think the nest way is to get the needel out and make sure they are nice n pointy with no wear round the cone shaped end. Check in the manual its all in there

true but i read that rubber nosed fuel cut off valves dont show wera that good. that true?

well you wont know till you get it apart. Where did you read that?

Am I missing something?

If you do the clear pipe thing and the level rises continuously its not sealing, eventually coming out of the emulsion tube past the needle. If it stops where it should the seal is being made. Is this too simple?

Obviously a pressure needs to be present so either the pump must be running or a header fuel tank rigged up.

Am I being to simplistic?

markzxr400l3 wrote:Am I missing something?

If you do the clear pipe thing and the level rises continuously its not sealing, eventually coming out of the emulsion tube past the needle. If it stops where it should the seal is being made. Is this too simple?

Obviously a pressure needs to be present so either the pump must be running or a header fuel tank rigged up.

Am I being to simplistic?

am i missing something? clear pipe thing? crack pipe? bong? pippette?

markzxr400l3 wrote:Am I missing something?

If you do the clear pipe thing and the level rises continuously its not sealing, eventually coming out of the emulsion tube past the needle. If it stops where it should the seal is being made. Is this too simple?

Obviously a pressure needs to be present so either the pump must be running or a header fuel tank rigged up.

Am I being to simplistic?

I see what your saying but fuel wont rise any higher than the level inside the float bowl. It will seal eventually just wear on the needle will cause the level to rise further. Your supposed to have a fuel tank connected too, but i didnt bother and still measured correctly.

Its in the link here

http://www.zxrworld.co.uk/Manuals/H%20M ... er%202.pdf

if the valve is leaking (or more likely the o rings round the valve holder) the level will not stop rising until it equals the level of fuel in the tank.

quick check ..

airbox off
start engine
blip the throttle a few times whilst having a look into the carbs, if fuel is gushing up past the needle the valve isnt sealing correctly

clear tube thing = attach some clear tube to the nippley bit under the float bowl (by the drain screw) fold the tubing round the side of the carb and hold it vertical (up, not down !), then slacken off the drain screw a few times till fuel flows into the pipe, sede where the level settles at, .. physics says it'll sit at the same height as the fuel in the float bowl.

[quote="zimm"] (or more likely the o rings round the valve holder) quote]


that never even crossed my mind. nice one lol. got a lovely block cracked in 2 places to be welded before i get to check carbs

good luck getting that welded up !

if its a no go, ive some here.. they'll need honing, but are on the standard bore size.