KZ1000A1 1977 CARBI PROBLEM ...HELP..HELP

[Carbiez1000]

Needs some help......
Howdy to you all... just new....

I have a KZ1000A1 1977 and I have just got her back together after 3 years........I have hit a wall as I can not get it to run without the chock off??????
CHOCK ON....GOOD
CHOCK OFF....NO GOOD

IF SOME ONE HAS HAD THIS PROBLEM OR HAS IDEAS I WOULD BE VERY GREATFUL AS I HAVE ONLY ONE MORE CLUMP OF HAIR TO PULL OUT..... I HAVE A ORIGINAL MANUAL AND I HAVE DONE EVERYTHING BY THE LETTER...( WELL I HOPE ) IS IT LEAKING AIR? HAVE I PUT SOMETHING IN WRONG??? ARE THEY DAMAGED?????

CHEERS TO YOU ALL

THEY ARE MIKUNI 26MM CARBS...WITH THE PILOT ADJUSTER SCREW UNDER THE BOWL

[oldman]

Give me more details as I am a carb idiot and have worked on them since 1957. e mail is phtelec@msn.com

[mike-s]

Firstly we know fuel is getting from the tank to the carbs as it starts with the choke on. Have you done a compression test? It can sometimes be a bastard to start/get going if compression is low. Otherwise i would suggest taking the carbs out, cleaning the idle jet and using fishing line to make sure that the fuel passageways are clear. Another thought is to take the emulsion tubes out and clean them out too.

[Six Addict]

Calling gos!!

[Gosling1]

Mike has listed some of the common problems...

basically, if the bike is actually 'running' with the choke on, then just stalls out as soon as the choke is turned off - the problem should be restricted to fuel flow.

It will be either a major blockage in the low-speed fuel circuit. It could be blocked pilot jets, or a blockage inside the internal fuel lines within the carbie bodies, maybe needle/seat issues and/or float height incorrect. The fuel tap should also be checked, and especially the internal fuel filter that sits on top of the fuel tap, inside the tank. If it has been 3 years since the bike last ran, then this filter could be really dirty.

How old is the fuel ? I assume that the normal tests for fuel-flow have been done ? ( take fuel hose off carbie - turn on tap - watch fuel run out freely. Replace hose on carbie, turn on tap, remove either outer float bowl and make sure fuel is flowing ?)

The best way to clean carbies out, is with a pressure-pak can of Carb Cleaner (Wynns or similar) - and compressed air, using an 'air-duster'. This is by far the best way of cleaning internal passages within the carbie bodies.

The correct adjustment of the pilot air-screw on these 26mm carbs is critical for good running. For 77 models, the pilot air-screw setting is 1 1/4 turns out ( from fully the fully-seated 'in' position).

[Carbiez1000]

Ya all good.....
I was having a chin wag with a good mate and moto owner( who just bought the 2010 trumpy Rocket 3.....Hell of a bike )....and we talked about the jet needle... I actually did not assemble this part.... and maybe and only maybe the jet needle is set to HIGH and not closing.......when the slides are shut, turning the mains off and on from the starter circuit.. So if it was adjustered (the jet needle) too high and does not seat right at idle and causing to much fuel......engine not happy.....THIS IS A THEORY....The neede jet has about 5 settings and maybe the mechanic set them wrong.....maybe they didnt know........
SO IS THIS A POSSIBLE LOGICAL THEORY??????

[mike-s]

Gos, I figured i'd give him a starting point and you'd find this thread in a timely manner!

[Gosling1]

cheers Mike

If the clip position is set in the wrong spot, you will get problems with how the bike responds once it is up and running. The clip-positions in the jet-needle do make a difference from around 1/4 to 2/3 throttle opening. They don't make any real difference at all for the starting or idle circuits, and this sounds to me, from your description, as the area that is causing problems.

[Carbiez1000]

Very true....But what if the needle was set at the bottom notch and did not seat..would fuel flow through? allowing too much fuel at idle?
Please bare with me.......this is all a bit new.......

The correct adjustment of the pilot air-screw on these 26mm carbs is critical for good running. For 77 models, the pilot air-screw setting is 1 1/4 turns out ( from fully the fully-seated 'in' position).
Just a question ( from fully the fully-seated 'in' position). IN TIGHT OR VERY FIRM.....

[oldman]

The pilot air screws adjustment is variable and that could be your problem. 1 and 1/4 turns out is a preliminary setting. It may in reality be much different and I've never seen a 4 carb setup that had all the pilot screws set the same. Also (my memory is not serving me right now) some needle and seats had a compression spring to compensate for bumpy shit. The float should be set with the needle valve spring uncompressed. If you set the level with the spring compressed the float level will be too low. You need to determine what your problem is, lean or too rich, before you can effectively trouble shoot this problem. If it stays running with the choke partially closed but dies when you open it, it's too lean. You can pull a plug as soon as it dies and look at it, if it is wet from too much gas it's too rich. Get a squirt bottle with some gas in it and when it starts to die squirt some gas into the intake and see if it keeps running. You stated you have a service manual once you determine the problem, (lean or rich) you can go from there. If it is lean I would turn the pilot screws out 1/2 turn and see what happens. Also all the other suggestions on this thread are good as well. Jim Beam is the key to finding god who is really a dog.

[mike-s]

Once everything has been cleaned out you should look here

[Gosling1]

Very true....But what if the needle was set at the bottom notch and did not seat..would fuel flow through? allowing too much fuel at idle?
Please bare with me.......this is all a bit new.......

The correct adjustment of the pilot air-screw on these 26mm carbs is critical for good running. For 77 models, the pilot air-screw setting is 1 1/4 turns out ( from fully the fully-seated 'in' position).
Just a question ( from fully the fully-seated 'in' position). IN TIGHT OR VERY FIRM.....

If the needle was set at the bottom, or lowest possible position ( ie the clip is in the top notch) - fuel will still flow through the starting and idle circuits. That needle does not *seal* anything off at all. It just controls the flow of fuel through the range of throttle position I mentioned in the previous post. If you set the clip in the lowest clip position - this raises the needle to its richest setting. This always confuses people - lower the clip = lifts the needle = richens the mixture, or raise the clip = lowers the needle = leans the mixture. Always start with the clip in the middle position of the needle. They rarely need to go more than 1 position either side of this, for most street bikes.

When you screw the pilot air-screw into its 'seated' position - you don't screw it in tight at all. You just screw it in, until you can feel the screw bottom-out lightly. It is from this position, that you back it out 1 1/4 turns - as Oldman says, this is the 'preliminary' or starting position for this jet. It may need to be altered, depending on what other mods you have done......ie pod filters fitted ? Or stock airbox with new filter ? Stock pipes fitted or 4-1 extractors ?

Have you cleaned the filter attached to the fuel tap ?

[Carbiez1000]

Thanks for clearing that up..... Everything is good fuel wise...Fuel cock is original and NEW....But at the moment just running it from a elevated fuel source...no obstructions.....

[bonester]

Vacuum leak?

[Carbiez1000]

What a day......But we have found a result.........and this happened in the last 1/2 hour..... Well what can I say....... I set the float heights to 25mm AGAIN and for some reason I said to myself check the float needles/springs and found that I had 2 sets and one set the springs went to the bottom and the other didnt go to the bottom??????? Well I had them mixed up. Well I changed to a complete set( bottom out ), turned the pilot adjuster screws out 1 turn and presto......idle not good but IDLE....off the choke......
Now.......both sets are new, but who would think there was a difference... One set was after market and the other original....... Is this common......
We had a base to work from.... The middle end was lacking so we uped the 17.5 jets to 25? much better but it needs more so we are going to drill up to 30 on a spare set and see how it is.....We are thinking that these are not the original carbies??????
Love to hear from you guys cheers for everything