Fuel Issue

V

van rock

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Ok so i thought we had it figured out
http://www.zl-oa.com/community/threads/Temp-light-and-running-rough&p=146558#post146558.15048
I have some new info maybe ya'll could put some ideas together.....
So I completely disassembled the gas cap thinking I had found the venting issue (BTW whos the genious that designed that thing!!! HOLY @)$&@$ That thing is way to complicated for a stinkin gas cap...) got it all back together and away I go after a fresh tank of fuel........at about 50 miles bike runs ok but when twisting the throttle it sputters and chokes..(60mph 6th gear).....just happened to have my spare key so i popped the lid and continued to roll........bike will not excceed 70mph at max throttle...switch to reserve....nothin.......shift down to change rpm...nothin...switch to prime....nothin...pop sputter...choke...as if starving for fuel....when cracking throttle......heres the wierd part........
come to a stop...running smooth but will just die...fire it back up...and nail it 1,2,3,4...to about 8k each...no problem runs great!!!.....WTF???....swing by fuel station top her off...(1.7 gal)....problem goes away....bike runs perfect.....
I have removed petcock...screen clean ...diapghram clean and perfect...fuel venting hose clear....fuel cap flows air both ways....plug chop reveals slightly rich mixture but nothing excessive?................

Any other ideas?......Help! I wanna go on a poker run today and it really sucks when I can't blow the doors off all those Harley riders....*wink*
 
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Do you have an inline filter on the bike?

I have found some filters will create a lean condition due to a vapor lock of sorts as the tank gets close to reserve.
 
Yes there is an inline filter in place......I'll by-pass it for todays ride and see what happens....Thanks for the input I really appreciate!
 
Started Doing it again yesterday....pulled over and did a plug chop....WAY TO RICH!!....plugs are jet black!....just popped the carb slides to adjust needle....hmmm no adjustments...Guess this aint my old Z1....
Replaced plugs and am headed to figure around how to adjust mixture....Thanks for the input all!
VR
 
We are talking about a Zl 1000 correct? Are there no screws in the carbs? ( adjusting) if they are there ,turn them all in and lightly seat. Back each out to 2.5 turns from lightly seated. If this doesn't do it then you need to pull them and have them gone through!
 
You said in your 1st post that you could nail it all through the gears and it would run then start acting up when you tried to level out. You are running fuel through the main jet when you were running it hard and it will most likely run okay because that is your biggest jet in the Carb. While cruising you are relying on your pilot circuits and floats to maintain. Sounds like these carbs are sick and need to go to the doctor . Can you say "rick west"?
 
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well since this post i have had a few issues with carbs.....the previous owner had the mixture screws turned out 4 turns...that fixed the richness problem...

...took em apart and gave them a good cleaning seems to run pretty good but I'm still having the high speed issue...

can't get the bike to do over 100 from a 50-60 mph punch...??
 
Give us a little input on the set-up? Stock? Stock airbox? Stock exhaust? It doesn't have a dynojet kit in it does it? If it is a factory fuel tap, I would make sure it is ok...Does it have figure 8 disease? Another thing you have to think about is if the circuits of the tap work like they should (prime, on, res)...On my 1K when I first got it, it would run fine until I got close to reserve, then I would smell a wiff of gas and it would sputter and I would have to flip to reserve. It would start back up and run, but run like crap until I topped it off and went back to ON....My tap was figure 8'ed and the screen was junk. Someone along the way had put an in-line filter in it also. I am assuming since you talk abouot the complexity of the gas cap/venting, that you have a 900?

Not being sure of what all you have done to it and when the issue started, I will say that the best thing to do is start with all the basics. First and foremost what kinda shape are the plug wires in? If they are original, I would seriously think of replacing them. Go down to an outo parts store and buy yourself a 4 cyl universal plug wire kit with 7mm (or 8mm) COPPER CORE plug wire. Replacing the wires does not take that long. With a factory fuel tap, you have to look VERY closely at the place where the screen body (plastic) meets the tap housing (aluminum). That connection is an oval shape normally. What happens is the plastic screen will suck in at the middle over time and the oval now will resemble a figure 8. When the screen body does not fit tight in there, unfiltered gas can go thru there and it WILL very easily plug a pilot jet and/or your progession holes of idle port. The first year I had my 900 I pulled carbs 6-8 times to clean them. I was not aware of the figure 8 disease (mine had it) and the tank needed cleaning. Mine also had an in-line filter and all of that combined gave me fits. If you have a good working tap you should not need an inline filter.

Unlike a car, there is no fuel pump so it is easy for an in-line filter to get air in it that hinders the flow of gas. If you have the filter oriented on its side, what can happen is the inlet and outlet are actually on a higher plane than the middle of the filter body. The fuel gets in there and sits and now the inlet and outlet are only connected with air not fuel, hence the air lock. Since the bike is moving, hitting bumps, etc, the fuel can slosh and sometimes you get fuel and an instant later you get no fuel. More fuel in the tank, creates more weight to push the gas thru gravity and it may air lock less or not at all. With a lower level in the tank that equals less weight and the possibility is greater to air lock it. If you do you have a filter (I would advise against it) you should orient it up and down and not lay it sideways. If you have a pingel tap or you are SURE you have a correctly working factory tap, you should run a good clean fuel line direct from the tap to the carb T and make that run not have a lot of excess line.

How is the air filter? Should be clean as to not choke off the air (less air= rich mixture). As stated previous if you are stock in your set up, the pilot air screws should be 2 1/8-2/12 turns out from lightly seated. Float levels are important too and if any carb work has been done, you need to make sure it is jetted correctly. If you take the tach to 10K on first gear and second gear shifts (it won't hurt it....trust me) by the time you bang into 3rd and throttle hard, you should be above 80 mph. The top of 3rd (10k on the tach shifting to 4th) should have you right around 100 mph
 
WillyD were talking 100% stock bike with a K&N filter in the stock air box........inline filter is oriented straight up and down....took off yesterday and had nothing but rough running at highway speeds finally got to a hotel and wound up pulling petcock out an discovering I do in fact have figure 8 issues..........pulled #1 and #4 plug to try to see what is going on ...plugs are black like carbs are dirty again....wich makes sense with the figure 8 issue.....along the way back home this morning just running horrible at highway speeds anytime you back off the throttle it seems to starve for fuel...call me crazy but it seems like when the wind blew it would stutter as well....
?? around town or at lower speeds the bike seems to run fine........my biggest concern is the oily smoke that started about half way home from this fiasco....
I've searched the internet over and cannot find that filiment anywhere it appears you have to purchase and entire petcock (51023)
Gold Drakul - 6th gear about 6500 it starts crapping.......more RPM (ie shifting down) does not change issue........obviously after yesterday and today I have carb issues and after a compression check to make sure I still have rings i'm going through everything....can someone educate me on this pulsing coil / igniter?? just want to confirm its working properly.........Thanks guys I can't tell you how much I appreciate your input!!!
VR
 
Simple Ignitor and Pickup coil test is to backprobe the coil primary side wires with a 12v test light connected across the + and -. Start bike the test light will flash each time the 1-4 or 2-3 cylinders are at TDC. If you have a missfire at idle it should be easy to see the test light flash and hear the miss happen at the same time.

No flash w/miss ignitor/wiring/pickup problem

Flash w/miss coils/plug wires/plug caps/plugs problem
 
Make sure to ohm out the plug wires from end to end; just helped a fellow member yesterday with a ZL1K that was idling reasonably well and would break up around 6500 RPM under load [in any gear] - his plug wires were junk and the boots where the resistor sits were so badly corroded that only 1 actually measured close to spec [others where 35Kohms+]. Made new wires from Accel 3008 spark plug kit like WillyD suggested, disassembled boots, wire brushed spark plug connector, resistor ends and spring and used zlMark's trick of a cue tip in a drill with metal polish to clean the brass contact at the very bottom of the boot. Even with all that still had two boots that had to be replaced; one didn't have continuity from where the plug wire screwed in the boot to the contact on the inside, and one was so badly corroded that I couldn't get the resistor out of the boot. Bike ran very strong afterward.

Bottom line, while these bikes are known [with good reason] for finicky carbs, there are other things that can and do go wrong. Verify the resistance of the wire assemblies, for a quick check without taking the tank off all you have to do is measure through the boots where the connect to the spark plug to the same spot on the other plug on the same coil [IE 1-4 and 2-3]. Total resistance should be between 20K and 26K; that's approximately 5K for each plug wire resistor and 10-16K for the secondary coil windings [factory spec]. If the measurement is higher than that, time to investigate, if it's significantly lower than 20K may have a coil issue or someone put the wrong resistors in the boots.

One last suggestion, the best and most accurate way to check float levels on the carbs is with them on the bike, the bike supported in the middle to level it side to side [not leaning on the kickstand] and using a piece of clear plastic tubing as described in the manual. The 17mm float gauge measurement is a factory assembly spec with all brand new everything; the minuscule wear tolerances of the various pieces over 25 years can add up to inaccuracies and incorrect settings. The purpose of the 17mm measurement is to ensure that the bowl is filled to the flange, so you may as well just make sure it is via the clear plastic tube. Make sure to hold the tube in the same place [don't move it up or down] and keep it in place for at least a minute or longer, I just had a carb that would measure correctly to start and them weep about 5 minutes later.
 
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