only running on 3 cylinders.???

[Leelofty101]

Hi guys. Bike - z1000ltd K
I've been struggling to get my bike running on 4 cylinders. Here is a the run down!!
Bought as a non runner but it did start with carb cleaner and sounded sweet for about 3 seconds. Got running but was really rough. Drafted Chris Poll in and managed to get a new Dyna S CDI fitted to match the coils and set the timing. Still did not run properly though.
Found out that the head was blowing so had the head skimmed and valve seals done with all the valves re seated.
Fitted head and re shimmed. Put carbs back that have been ultrasonically cleaned and new carb kit inside. New throttle cable fitted. Filled up with new petrol. Shims checked again and the timing checked.
It starts easily and goes off choke very quickly but will not run on number 3 cylinder. New plugs fitted which are all sparking, there's petrol in every No 3 carb but No 3 cylinder doesn't seem to want to draw the petrol in?? compression and sucking going on which seem to be the same as the other cylinders(not accurately tested though). Will run without the plug cap on and even with the plug out! It looks like the top of the cylinder is wet too!!! I have also put the carbs 3 and 4 onto cylinders 1 and 2 and both cylinders run. Was going to try 1 and 2 carbs on 3 and 4 cylinder aswell but the battery died.
I'm now stuck and have been told it could be the rings or valves not closing but I'm pretty sure somewhere along the line it ran on 4 cylinders already!! This has been going on a while now and I really would like it sorted. If there's anyone with any more ideas i would gratefully appreciate any!!
I would like to get it on the road sometime this year please.
Many thanks
I'll try again tonight and tomorrow and the next.............!!!

[chrisu]

i'd do a leak down test.

Have you changed the No 3 plug cap ? - if not i'd do so. i've had a plug cap go bad before.

[Leelofty101]

I'll try both those thanks

[Pigford]

Cracked cylinder or even head?

#3 lead / coil connection (HT) dodgy?

Twisted crank - clutching at straws with that one

[Redbeard]

What ohm coils has it got? I may have a spare. I have ngk plug caps too that are surplus if you want them.

[warren3200gt]

Carb cleaner down the carb throat is not the same route petrol takes from the float bowl or when under choke. You mentioned the carbs have been cleaned, was all the fuel and air passages blown clean of shit after sonic cleaning. Sonic cleaning loosens shit but you still need to shift it. Where the jets blown through.? Blocked pilot jet/system on carb 3 is my guess.

[ZedHead]

Carb cleaner down the carb throat is not the same route petrol takes from the float bowl or when under choke. You mentioned the carbs have been cleaned, was all the fuel and air passages blown clean of shit after sonic cleaning. Sonic cleaning loosens shit but you still need to shift it. Where the jets blown through.? Blocked pilot jet/system on carb 3 is my guess.

I agree, still sounds like carbs. My only question is why is the cylinder getting wet?

[warren3200gt]

Carb cleaner down the carb throat is not the same route petrol takes from the float bowl or when under choke. You mentioned the carbs have been cleaned, was all the fuel and air passages blown clean of shit after sonic cleaning. Sonic cleaning loosens shit but you still need to shift it. Where the jets blown through.? Blocked pilot jet/system on carb 3 is my guess.

I agree, still sounds like carbs. My only question is why is the cylinder getting wet?

Dunno, mixture too far out to run? Plug not sparking under compression? I'd check pilot sytem/ jet and do a compression test first as its easy to do. Then go from there. If youve got fuel, compression, and a spark, as the other three run cant be ignition or cam timing, it should do something. I still think its pilot jet/system.

[trikerdrew]

Have to be honest my heart goes out to you on this

I would be reaching for petrol and polystyrene in = measures. No hair left to pull out!

Hoping carb blow through will restore sanity?

God willing!

drew

[DavidZ1R]

Just a long shot, when the engine has been standing over night, take out the plug, put something, a stick or similar in the cylinder and rub the piston crown, see if it is oily, if it is that could be the problem, a touch to much oil will foul the plug, nd stop the fire ring, when the enine has warmed, change the plug, see if it runs then.

[Pigford]

Used to whip plugs out & heat with a lighter back in the day....... usually worked!

[Leelofty101]

Thanks guys, I've tried changing plugs and leads. The piston top is wet with petrol I'm sure cause it's not oily. Remember the carb no3 works on the other cylinder. I really think now it's as simple as a Dodgy lead even though they're new with the coils, I didn't buy them! I was getting a shock when I was putting my hand near the coil maybe it's shorting out cause it's not properly connected or the lead is fucked?
I'm busy for the next few days and the battery has been on charge. I'll keep you all posted. Really appreciate your help.
Thanks again.

[warren3200gt]

If you suspe t a lead just swop lead 2 & 3 over and see if the fault moves with it. I am asuming a ltd has the same coil set up as the rest. 1 coil does 1& 4 & the other does 2 & 3. As its a,wasted spark system doesnt matter which of the ht leads goes which cylinder.
Start it in the dark with the tank off. Youll soon see if its shorting.

[johny brando]

I'd be doing as some one else suggested earlier ...swapping over coils & leads & HT caps between 1 & 4 over to 2 & 3 .....but first I'd be doing a compression test as you could on #3 have a sticky or bent valve thats gone under the radar & it's not sealing ... or broken rings . Wet piston indicates fuels getting there ....might be an idea just to Turn fuel on the fuel for 30 seconds ,then turn it off again ...now drain #3 Float bowl , capture fuel from the drain screw and measure the volume in that float bowl and do the same on another bowl and compare volumes if ...if there almost the same you can dismiss fuel really ( having said that......another quick thought though...Choke on #3 could be stuck permanently on too..... i.e. a choke plunger seal failure of some description leaving the choke permanently on even though it appears off........most zeds don't want or need full choke at all !..it's just a thought because you stated in once it fired up OK for a couple of seconds then dropped onto 3 ....so if that #3 choke plunger was still internally in the full ON position without you knowing well....that would kill that cylinder straight away & every thing else would still appear OK !!!! ) Good luck & happy hunting, Johny B.

[z1bman]

remove the plug caps & see how far the spark will jump hold the lead against the head & slowly moving it away until the spark breaks down