Carbs again??? Or still!!!

[Ken Talbot]

Originally posted by noeleo
... I removed the carb bank, disassembled the fuel bowls and proceeded to clean out the jets for the enricher circuit in the bottom of the bowl. When I applied air pressure to the jets, no restriction was found. I then proceeded to completely disassemble the carburetors. I applied compressed air to every passage in the carbs, and found no restriction. The enricher still doesn't work. ...

Just to confirm, after you cleaned out the jet in the bottom of the float bowl, you also made sure the rest of the enricher circuit was clear all the way up the brass tube and out the orifice at the top of the carb throat, just behind the top of the closed butterfly:

(You would have to plug this little hole in the side of the brass tube, or your air would escape here even if the passage "above" it was plugged)

[prometheus578]

Taking a different avenue of approach

As everyone is pretty thoroughly covering the carb issues, there's no need for any input from me there.

I'm worried that the starter is going out from trying to start it cold. (Extended cranking

How old's the battery? How strong is it? When you crank it cold, does the starter spin at the same speed as when hot? Have you been having to jump it when cold? If jumped when cold, would it fire right up?
A weak battery(slow crankin'), would give you trouble startin' when cold. (highly volitile starting fluid would fire, though) You finally get it to fire, and run it for a while, charging the battery back up. (hence, the easy starts when hot) Let it set for a few days... battery drains back down.
If you don't have a jumper battery and cables, do you have a battery charger? Throw it on the charger overnight and hit it first thing in the morn. What happens?

[xj11john]

When it gets just a fog of ether, it fires right up. You can drop it in gear, and just ride. No bogs, hesitations, etc. Runs as good once you get her started as it does warm. Thought about the flooding, but never raises oil level and dry in the air box. I even used the old trick of pulling an oil sample and lighting it. No gas residue.

Neo,

You say once you give it a shot of ether it fires right up and you can jump on and go-is that immeadeatly or do you have to let it warm up.

If you dont have to warm it up you definetly are running way rich, may not start being that rich, but once fired up it runs fine,
Does the exhaust smell rich? or black in color?

Have you bi-passed the octopus yet? Mine had a bad diaphram in it, but it would still start, but it didnt do its job of stopping the flow of fuel when the bike was not running.

I would definetly bi-pass it and see if it helps if you have not already. Hope you find the gremlins soon, good luck.

[pggg]

[LoserShoes]

Have you pulled a plug after it wont start cold? If it's wet that would be a rich/no spark problem. If dry thats a no fuel problem.

Most likely you have a combination of problems that are stacking up when cold.

The weak battery suggestion sounds plausible, along with too rich.

Have you tried half or full throttle and no choke when trying to start cold?

Steve

[fxrer]

I’m still of the same opinion as Ken on this problem. With only 5200 miles on the bike, it seems more likely gummed up carbs than anything else.

You cleaned the float bowl enricher jets? So, instead of compressed air, if you stick the narrow squirt tube from a can of carb cleaner into the jet hole, does the fluid flow freely out the other end of the passage, on each bowl?

If so, check the rest of the circuit. In Ken’s picture above, gas flows from the bowl, thru the jet, up that brass tube (you can see it on the outside of the carb, by the throttle shaft) to the plunger chamber above the venturi. Remove and check each plunger. If it all looks good, try to squirt fluid up the brass tube (you need to plug that little hole Ken points out), and make sure you see fluid entering the chamber thru the little orifice at the top.

If fluid flows freely thru all the passages in each carb’s circuit, then I’m stumped.

[xj11john]

A few more thoughts ;

check for vacuum leaks-from carb intake-hoses, & little hose that goes from octopus to #2 intake hose (if its like my xj- havent checked your specific carb on parts catolog) but nontheless, check all hoses and intake boots/hoses etc.

also if your carbs have the vents on the top nipples of the carbs, they may be clogged or fuel lines could be run to them.

if any of these issues have been covered disregard.

keep at it, you'll get it !

[noeleo]

In response to Ken Talbot who stated:

Just to confirm, after you cleaned out the jet in the bottom of the float bowl, you also made sure the rest of the enricher circuit was clear all the way up the brass tube and out the orifice at the top of the carb throat, just behind the top of the closed butterfly:
(You would have to plug this little hole in the side of the brass tube, or your air would escape here even if the passage "above" it was plugged)

Thanks, Ken. Yes, I did check the rest of the enricher circuit. Blew through with carb cleaner and shop air. Only other place it should come out is in the throttle bore, right? That is, when the enricher valve is open.

In response to xj11john who stated:

You say once you give it a shot of ether it fires right up and you can jump on and go-is that immeadeatly or do you have to let it warm up.

Thanks, John. In the ether situation, you can just ride off. Of course, when I do that, there's usually a two or three minute lag while I reinstall the seat and pick up my tools. That's usually all the time it needs. Then it runs great.

In response to LoserShoes who stated:

Have you pulled a plug after it wont start cold? If it's wet that would be a rich/no spark problem. If dry thats a no fuel problem.

Thanks, LoserShoes. The one time I did pull a plug, it was dry.

More info:

I just went out to start it so I could write the latest. Hadn't been started since Saturday. It got into the low 80s today, and still is 71 degrees outside. On the fifth attempt, it finally hit a few times, and ran on just one or two cyls. Picked up the others quickly, but still ran like it needed choke. If you try to goose the throttle, just spits and backfires in the airbox. After two or three minutes of idling, now you can give it some throttle and go. Before I started it, I checked a plug and it was dry. I also tried putting the petcocks in the "Prime" position, which didn't seem to help either. I used nothing external to start it today. When it was trying to run, I pulled out the "choke" and it died immediately. If you twisted the throttle any amount while cranking, would not "hit a lick". Since I got another ride last Wednesday, I will pull the carbs again and look at what to do. Anybody close to Arkansas that I might take these carbs to while they are off to give an opinion? I'm getting desparate. I really love to ride this machine.

Also, I'm looking for a speedo to replace mine. It swarmed on Saturday in the Toy Run. Will settle for an 85MPH unit, since that was original. Thanks

[pggg]

Noel, before you go stripping the carbs again, unscrew the carbs' fuel bowl drains underneath, to check that there's really petrol in there when you start it cold. I'm picking the carbs are O.K. but the fuel supply is dodgy. If there is heaps of petrol in the carbs when you're attempting starting on cold, well, strange to say the least. It'd have to be the enrichener circuits then. This is assuming the electrics are all O.K. P.S. unscrew the brass connecters inside the plastic sparkplug leads (if they're slotted) and check out inside for gunk.

[LoserShoes]

Sounds like its real lean when it starts, probably a carb cleaning is needed. How about some trying some Sea Foam if you can find it? Might save a carb teardown.

Steve

[robywan_kenobi]

I don't know if this will help or not, but I was having a similar problem just a couple of weeks ago. Actually had the problem for a long time, just fixed it a couple of weeks ago. My bike would always start, when cold I would have to use the choke, but it would always start. But sometimes after it started, as I would start to pull away, it would almost die. Every time I would twist the throttle, it would almost die. I would have to sit and wait with the bike just barely idling and after a couple of minutes, I could ride away no problem. I never experienced this problem when the bike was warm. After reading through this forum for months, I started getting the feeling that the bike was lean at idle, so anyway, I backed my pilot screws out another two turns and, voila, that issue has gone away. As a matter of fact, I rarely have to use the choke to get it started. Of course, I live in South Texas and the temps here are still in the upper 60s/70s in the mornings. Close to 90 in the afternoon. Also, I had another symptom that may make my issue completely different than yours; I had some backfiring on decelleration, that too has been fixed by backing those pilot screws out. Like I said, don't know if this helps or not, but if you back those pilot screws out and it doesn't fix it or it makes it worse, you can always screw them back in to where they were. Not a whole lot of time lost.

[xj11john]

Once its running did you do the wd-40 or started fluid trick to check for vacuum leaks?

I also started thinking about your diaphrams, but you have probably checked them for holes, and what level they are set at, I believe there are three settings for your carbs, anyone correct me if I'm wrong.

I'm pretty new at these carbs but after going in mine after overflowing, and replacing float valve needles and gaskets (o-rings) , rejetting due to 4-1 exhaust and ind. pod filters it is running almost perfect, pulls hard.

Now the next step for me is to do the washer trick to raise my vacuum needles (main needles-whatever) since my xj doesnt have the ajustable ones, and I should be running better at 3-4 grand rpms.

Dont give up, and good luck with it. It will pay off when its purring again.

[fxrer]

I’m sitting here, with a spare carb and a spray can of cleaner, trying to figure this out.

Still focusing on the enricher, I removed the float bowl, and the enricher plunger retaining nut. Then, with the little hole in the brass tube (in Ken’s picture) covered, and the plunger “in”, I sprayed cleaner up the tube. No fluid flow.

Then I pulled the plunger out, repeated the test, and fluid squirted out from the orifice, back in the plunger chamber.
(where it's supposed to)

So, if these same passages in your carbs are likewise clear, is it possible that the plunger in one or more carbs is not being pulled out? Maybe the forked tang on the choke activator shaft is not properly engaged with the neck of the plunger? Or, maybe the detent screw that secures the tang on the shaft is loose or missing, so the tang slides on the shaft without pulling out the respective plunger? That’s all I can think of.

If you ever do discover the cause of this problem, please post the answer, because it's driving me nuts, too!

[noeleo]

Originally posted by pggg

Yep, that's it. The best fix-all on the market.

[GNEPIG]

.. strange i'm having the very same problem with the Ugly bike, the very same.. but insted of using starting fluid i pull off the air cleaner on # 4 cylinder and cover the carb with my hand until my hand gets wet, which is about 3 revolutions, it starts on #4 then the rest follows very shortly after.. the Ugly bike has the later style 4 hole carbs on it
.. every thing neoleo has described is exactly how mine is acting