Eh, who needs jets and screws anyway...?

Similar to Moonwell's post, I now have what appears to be a missing cylinder and many of my symptoms are similar.




Firstly, I apologize for the length of this post. I'm trying to avoid cross posting while respecting that certain issues are better posted to their appropriate forums. At the same time, I don't want to miss information that might be relevant. I have been working through some troubleshooting of "clunking" issues in my post under "Engine" which it sounded like may be misadjusted carb related:

kzrider.com/component/option,com_joomlab...w/id,148733/catid,2/



To summarize what I've done up to (what I believe) is (currently) a carb related issue:


A week ago I added some seafoam to my fuel and acquired a new oil filter and oil in preparation of an oil change. I normally go through a tank of fuel in a little under a week as it is my primary means of transportation but due to sudden friend related issues, I have been driving to work and so have only been riding in the afternoon while running some errands. Had been running fine until yesterday morning with the fuel/seafoam mix (at a lower ratio than indicated on the can)

Noted no air leaks using a carb cleaner spray test.

Replaced the spark plugs with the manual indicated heat range. NGK B7ES. Was previously using a one higher heat range at the direction of a shop that indicated that a stalling at idle was because I was supposedly not running the bike hard enough. New plugs caused some fouling and stalling at idle when warm but runs fine above 1/4 throttle. Idle is rough, there is some very noticable rattling below 1500rpm (by the stock gauge) and is slows to an immediate stall. It sounds like there is a cylinder missing as the exhaust is "grumblier" than normal.

Noted the turns on my air screws (individually) as I put them all the way in (gently until just seated) and then worked them out to a base setting and went in and out to detirmine where they need to be. Noted some whitish crud around the screws for #1 and #4.


Here's where what I think are carb problems begin and I suspect my jetting is wrong and possibly I've misadjusted the air screws to compensate:

Working with my air screws, I noted that they were all at about 2 1/2 turns whereas #4 was at 3 1/2 turns initially (this would have been set by the same shop who incidentally recently rejetted and did carb kits on all 4 and at that time also commented that parts of the carb had been "haphazardly bent to compensate for adjustments that were out of scope" and consequently needed to be replaced). I set them all to 2. No amount of working out made any difference to any screw but working them all inward, the engine started to slow around 1 3/4 so I set them all just above 2 1/4 turns. Number 4, however, didn't respond to any screw setting. Swapped plugs around, (uniform sooting between plugs) received the same response. Had to turn up the idle significantly to maintain even 1500 rpm's.

Worked the #4 screw out until I was at about 4 turns and suddenly the tach surged up to 4000. Turned my idle back down and played with the screw to get it to respond to inward screw and back out to leave me at just over 3 2/3. Exhaust smells very rich but appeared to run about where it did before the plug heat range reset. Seemed to idle okay although just a tad bit rough. Supported itself, though, at 1200rpm without stalling.


Had to leave it for a few hours and came back to it. Started rough. Back to a rough idle. Sounds like a missing cylinder again. With the engine warm, no better but over 1/4 throttle it sounds like they may all be firing although there some serious hesitation on taking off/then recovers and seems to act pretty "normal".

To rule out electrical, I checked for spark (yes on all 4), and found no seemingly bad grounds. Checked all connections were clean and solid.

Had plans to do WG's coil mod but had not done it yet.

Pulled on the enricher for that carb which (previous to this week) usually made a audible difference and detected no change. Pulled the vacuum fitting and felt suction fairly comperable between all 4.


At this point, I'm thinking I should check for crud in the bowls and screen first, then check the uniformity of my jetting. Is there something obvious I'm missing?

Post edited by: Virii, at: 2007/06/21 15:39

Best thing to do is pull of the carbs and check in the float bowls and look at the jetting as you say. Also check the needle jets to see what setting the clips are on. Check fuel filter if you have one. That was the longest post I ever seen besides Gringo's, almost put me to sleep

I aim to please! Whomever can remain awake to the end of my nearly endless babbling deserves to be respected.

.....or so my ex says.

-Wolfie

Any backfiring?

Not specifically, but there is a "putt-ing" under throttle. None at idle.


"Purrrrr-ut...putrrrrrrrrrr-put-putrrrrrrrrrrrrr"

That probably doesn't come across well........

Making my way through it.

So, I'm currently running the right plugs. Drained/cleaned bowls, screens, filters, hoses, adjusted air screws. I'm now running as well as I was previous to reverting the heat range to spec (B7ES)

In adjusting my air screws, I've got consistantly (across all carbs) 2 1/3 is about where engine slows (going in). About 3 - 3 1/4 is where fastest idle begins. It's that consistant fast idle all the way out. What I mean by that is...I can go so far as pull the screw out entirely on every carb and still get the same idle. When I hold the screw up to the light and glare at it, it idles the same. When I put the screw on the kitchen counter and tell it it's in time out, same idle.

So what does that mean? Pilot jet too big? Exhaust smells rich. Plugs are sooted but not yet straight out fouled. Setting the air screw at 3 turns and running around for a while, I'm feeling some notable hesitation on take off (I don't rev much when I take off, just a tad above idle) and performance otherwise actually seems better than before my plug change. More responsive. When I come to a stop, I can immediately smell the whaft of rich air wrap around me...



Out of curiosity, I pulled a cap from the vacuum fitting on the intake manifolds and the idle surged higher and maintained about 500rpm higher than it was at.

Post edited by: Virii, at: 2007/06/21 16:01

No, haven't done the coil mod yet. This weekend! Maybe Friday afternoon...

Hi Wolfie, I'll say right upfront, I really don't know the quad carb setups but I have recently done alot of carb work on my twin. I know it was hard cleaning and ajusting my 2, 4 will be twice as much of a pain. But, I don't think I would trust the mechanic that did the carb rebuild. You've already said that he told you the wrong info on the plugs and I think you also mentioned that he had to bend something to fix something??? Maybe he had to bend the float bowl tang but did he do it correctly? Get an exploded view of your carbs from buykawisaki.com, and take em apart and see just what is there. It's not really that hard and is pretty intuitive, to put them back together, once you take them apart. You won't regret the learning experience.
As far as long posts are concerned, you will note w/the above missive, that I'm kind of long winded also:). I also subscribe to the idea that when you are asking for help, of this nature, it's best to put as much info as possible, to get the best help.
Good luck
Ron

ronjones wrote:
I don't think I would trust the mechanic that did the carb rebuild. You've already said that he told you the wrong info on the plugs and I think you also mentioned that he had to bend something to fix something??? [/quote]


I'm inclined to agree (for a number of reasons I won't get into) Normally, I would have opted to at least try to do the work myself but he came recommended at just the wrong time and for other reasons. It's a long story..

If I understand him, however, what he was relating was that he believes the floats were bent by the previous owner in an attempt to incorrectly compensate for the 4 into 1/MAC.

Asking for the original parts back, this is all I received:




Be aware, I cannot find numbers or markings on ANYTHING in this pile except what appears to be 2.0 printed on the main? jets and he wouldn't relate what he put in nor have I yet looked.

Post edited by: Virii, at: 2007/06/21 16:43

From that parts picture, it looks like you have fuel adjustment screws (the ones on the bottom of the picture) and air screws (the biggier ones on the top of the picture.
When I originally got my 650 it just had the air screws and a fuel adjustment screw only on #1 for some reason. I bought a set off ebay and replaced the #1 carb with one that didn't have the fuel screw.
If they are actually fuel screws they are mounted on the bottom of the carb in front of the fuel bowl. The initial setting for them is 1/4 of a turn out. If they are there, check that setting and then do the air screws all out 2 turns and start from there.
Do you know if your "mechanic" synced the carbs????
Ride safe.

you said you put B7ES plugs in, it should have B8ES, you are running a colder plug, it may not be firing correct with that plug

The 2 sets of adjustment screw/needles, tell me that your carbs are not similar to mine. I see the main jets but don't see the pilots. Are your carbs CV?, do they have a piston that slide up and down in the assembly? If it does you might want to check out the diaphram and jet needles as well as the needle jets(emulsion tube?)? Clean all the little holes and make sure the cleaner comes out somewhere other than where you spray it in. Mine have little screens attached to the float needle seats. Make sure all the rubber parts are removed before using cleaner. Other than taking everything apart and cleaning it, I got nothing.