TOPIC:

wrote:

Running only on choke and dying when opening the throttle suggests a seriously lean condition. Most likely clogged pilot circuits or leaking around the carb holders or seriously low fuel levels, or some combination of these.

Before I removed the carbs for cleaning it was revving fine on  cylinders 3 and 4,number 2 turned out to be a loose plug wire. I'll check for a spark on 1 and try running it and spraying carb cleaner on the rubber boots to see if  they're leaking.
 

Yesterday I tightened up the clips around the inlet rubbers, it doesn't seem to have made much different I'm afraid. There's a little pip on them which I'm presuming goes at the top as I think I noticed it there when I took them off. All have been refitted in the same position they came off including the clip fasteners  I also coaxed the no1 cylinder to life  by removing the carb top and squirting carb cleaner in there after cleaning the needle etc. No3 cylinder has stopped running so will investigate that today 

Ok have taken the carbs off again.

The jet above and to the right of the main jet is what I need to know about. The four small holes on the shaft of the jet are clear but on the crosscut end in third pic looks like a hole but doesn't seem to be. I can't blow through it so before I start shoving things down it, should it go all the way through to the tube end? I can't see how it would work if it didn't and it doesn't. The cast in pipework on the carb body under where it goes is clear.

There must be a tiny hole (0,35 mm) through the screw driver slot into the bleeder tube. A thin tooth brush nylon string will open it again.
Don´t use any metal parts or you will enlarge and de-calibrate the diameter!

wrote:

There must be a tiny hole (0,35 mm) through the screw driver slot into the bleeder tube. A thin tooth brush nylon string will open it again.
Don´t use any metal parts or you will enlarge and de-calibrate the diameter!



Great! Thanks will have a go at shoving something really thin down there tomorrow. From what I've read the pilot circuit takes over from the idle to help revving up.

 

The pilot circuit adjusting screw is under the de-ice fitting at the top of the picture. I have no idea how in the world you can get to that screw once the carbs are reinstalled.

The next time I have to take the carbs off my 94 Concours, it will be up for sale!

wrote:

The pilot circuit adjusting screw is under the de-ice fitting at the top of the picture. I have no idea how in the world you can get to that screw once the carbs are reinstalled.




 

That could even be plugged with tarnish if never removed or flushed with cleaner. Pilot system can be easily fouled on these carbs as there are multiple bleeder holes into the carb throat.



1990 CVK34 750 Ninja carbs on my KZ650 with Spectre motor.
 

wrote:

The pilot circuit adjusting screw is under the de-ice fitting at the top of the picture. I have no idea how in the world you can get to that screw once the carbs are reinstalled.

I suppose you'd have to remove the De icing plumbing first. Ok today I have cleaned out the four jets I mentioned in each of the carbs. I used a small ultrasonic bath and an old toothbrush. What do I need to do with that pilot circuit adjustment screw?  Have also ordered new airbox to carb boots and those coiled spring clips from those nice people at Power.
 

The carbs really need to be completely disassembled and carefully cleaned. As mentioned above, the pilot circuit consists of several (4 as I recall) TINY passageways. The fuel in that circuit is adjusted by those screws. The pilot circuit controls the fuel mixture at idle and at small throttle openings, and is always the first to get clogged up. The only way to clear the pilot circuit is to remove the pilot screws, plus the spring, oring and washer on each of them. The orings need to be replaced. You will probably need to use something like an e string from a guitar to clear all of the barnacles out of the tiny passages. The engine must be running while adjusting the screws, and I am pretty sure the plumbing has to be hooked up to do that. I had a couple of those bikes (loved them) but the U.S. did not get the deicinng apparatus, so I have no actual experience with it.

wrote:

The carbs really need to be completely disassembled and carefully cleaned. As mentioned above, the pilot circuit consists of several (4 as I recall) TINY passageways. The fuel in that circuit is adjusted by those screws. The pilot circuit controls the fuel mixture at idle and at small throttle openings, and is always the first to get clogged up. The only way to clear the pilot circuit is to remove the pilot screws, plus the spring, oring and washer on each of them. The orings need to be replaced. You will probably need to use something like an e string from a guitar to clear all of the barnacles out of the tiny passages. The engine must be running while adjusting the screws, and I am pretty sure the plumbing has to be hooked up to do that. I had a couple of those bikes (loved them) but the U.S. did not get the deicinng apparatus, so I have no actual experience with it.

Flipping heck more expense! Here's what I collected today from ZPOWER, they're only about 30 miles from me and the sun was shining 



 

My Mrs is a musician but not a guitarist, I'll ask what old violin strings she has knocking about. Alternatively, I have a really good little bike workshop up the road so I might ask them to sort it out as I have to change a diaphragm on the no1 carb that's on order after realising it wasn't making the same sucking noise as the other three last night. One of them built a TT winner some years back so they know their shiz.