Z400 shuts off when you shake it side to side

[John DInneen]

I have a 03' Z400, I repalced the battery, put a new plug in it and cleaned the carb getting it ready for the season, but I have run into a few problems that have never happened before. First it will not run off of choke, it has to be full or 3/4 choke for it to run. If I get it to run off choke it will shut off if you shake it side to side. I really have no idea on what to do. Can anyone help???

[Quad Dude]

any mods?? if its stock did you take the air box lid off?

[John Noftsinger]

check electrical wires coming off battery going tough fender after years the wire rubs to bare wire ,also check connector on box mounted on frame by steering stem(way up by top of motor) the wire leads to spark plug cap wire there,s a small wire that the connector hooks to box that gets loose and shuts off quad.you need to shake only connector to see if it shuts off quad there,s one one connector to check on right side at the radiator under fender or mounted to it is a connector that goes to starter button on handlebars run down wire to radiator and shake that connection. Those are the problems Ive had with mine hope this helps you out!

[John DInneen]

Thanks, I'll check these things out. I put an LRD exhaust on it last year with a Dino Jet systema long with a K&N filter. This is the first time I have ever had problems with it. I took the carb apart again today and found that i had some dirt in the idle jet. not sure if this was the problem but it seems to run a little better. I amstill unable to get it to run at only idle.

[John Noftsinger]

did you change main jet/ pilot jet/needle? but that shouldn,t make it shut off when you rock it side to side sounds electrical too me .

[John DInneen]

I changed the jets last year. This year I just took the carb apart and cleaned them all out, along with the needle. I took it out this weekend thinking that it just needed to be rode. Well that didn't work. It never shut off due to shaking it side to side, but I had to run it at 1/4 choke all the time or it would shut off. It would also die when i pulled in on the clutch if I didn't stay on the gas. Any more ideas??

[John Noftsinger]

your choke might have mud/water/rust in it I took my cable/handlebar lever off and got the pull knob thats on carb but when i took off cable there was rust and mud in there I broke my choke lever in 2003 rode without choke for years before Somebody sold me carb with choke knob on it they made.If you take off you can use a hairdryer to heat motor before starting worked for me for years but it sounds like your jetting is off or the choke is dirty did you move or at different altitude than last year that will affect jetting too ? did you check all the electrical connects by shaking them to see if quad shuts off? I think its a combo of both jetting/electrical imo.

[kaw45026]

It is the jet that is hooked to the float. It has bad seal had this prob on mine.

[John DInneen]

I have been told that I need to adjust the fuel screw, along with the idle screw. These go hand in hand I guess. My problem is that I can't keep the quad running unless it's on choke. I took all the jetts and needle out and cleaned them. (Ihave done this 3 times this week) Anyone have any ideas on how to adjust the fuel screw and idle screw. ( I know how to do it and where they are located, I just need some insite on how to do it with the bike not on choke.)

[John Noftsinger]

under carb there,s a knob when you get quad running turn black knob till the motor revs faster and set to your liking I just fixed the same problemyou had my quad shuts off too ,when I rock it side to side found that connector its yellow on right side of radiator was corroded in connector took connector apart wire by wire and sanded terminals now it fine but before it would shut off if you shaked connector think you might have same problem check this after you get jetting/idle right . Cause i still think it electrical and your is same year.

[John DInneen]

ok it's been over a month. I started my quad yesterday thinking that the problem would just fix itself!! Be t you can't guess, it didn't.

Here is whats happening or not happening. The bike will start on choke with no problem, i let it warm up and take it off choke and it stalls out, it will then not start unless the choke is on. I can only get it to stay running if it is is on 1/4 choke. I have pulled the carb, cleaned all the jutts and replaced the plug. The fuel screw is at 2 1/2 turns. I am just at a lose here. Any other ideas???

[mmsoup]

Own a 2008 that my wife rides and we had a similar problem last year. Turned out that the choke was stuck. The bike would run OK for a bit then stall. Especially sensitive to being on a side angle.
May not be your problem but something to check off your list

[EXKid416]

So more or less, runs worse with choke off. That tells us that it needs more fuel. Is this something that got progressively worse or only occured after you were messing in the carburetor?

Check engine compression first, then still, check your valve clearances. Very important. Check for any air leaks ( spray starting fluid at carburetor, boots, and fuel petcock, if it revs up you have a leak ). I would even try removing the airbox lid and see if it runs any better ( if its still on there anyway ). I've had a lot of electrical problems before, most of them dont act any different when you 'keep the choke on', they still die or 'rev limit' with or without the choke on. Oh, also, double check your float level.

Idle Drop Procedure: Set mixture screw 2 turns out from full in. Fully warm up engine, set idle speed to spec. Turn mixture screw out 1/4 turn at a time until a 50 rpm drop in the engine speed. Then turn the screw back in 1/4 turn from that point, readjust your idle speed. This should work out nicely. Wont work good if you have ANY restrictions in your pilot circuit.

[John Noftsinger]

Check float in carb ,see if it move freely and look at the plug thats hooks to it for corrotion also take sewing needle and poke jets all holes in jets need not be clogged .