Here's a brain teaser, White plugs and choke not do much??

I have all the misture set screws set at 3 1/4 turns now. Been turning them out slowly for past couple days to get rid of my lean condition. All plugs are white still. As well my idle inrichment( choke) doesn't do much since I started turning them out. They were set at 2 1/2 at first and when I pulled the choke then...the bike would race up to 3500 rpm. Now with the screws set out to 3 1/4 the choke barely gets to 2000 rpm on choke? Any helpful hints?

 

Ouch - you're going to need to tear into those carbs and find out what's going on. Need to find out what jet is where specifically -- and it sounds like the enrichment circuit might be clogged too.

 

These carbs have been down 3 times and are clean as clean can be. I had everything clear are jets etc. I also run a fuel filter on the bike so i don;t think thats the problem. I was wondering if timing could do it?

 

Well from your initial description, it sounds like the jets aren't right - 3.25 turns out is pretty far - you should be way rich by now. You're definitely running lean - and that means jets are wrong. Could you have installed them backwards by any chance?

Timing won't give this behaviour - it's definitely something in the carbs.

 

jets are correct....man, i wonder whats going on? this thing used to run so rich i was cleaning carbon off every time i drove....... I wonder if i developed a air leap in my YICs as I had to re-torque the heads to cinch an oil leak?

 

Is the spark strong?
How are your valves..
Is the carb bank synced correctly/recently?
At what engine speed are you doing your plug chops?
**EDIT** Just incase, what plugs are you running. Might be running a cooler plug than spec, you never know

 

Spark is strong, not sure about valves...synch...or what a plug chop is..plugs are spec though..

 

There is actually a little brown showing up but only on half the porcelin? and only on a few plugs?

 

Heres a link to a how to with syncing
http://www.xjbikes.com/Forums/viewtopic/t=2132.html

Here is my suggestion after syncing;
Warm up the bike on a 5 mile ride.
Bring the bike to your work area, place in neutral
Adjust the idle(while engine is running) and get it to ~1050

Then take the bike on another 5 mile ride, keeping revs above 5k to clean the insulators off.
Bring the bike to your work area, place in neutral again.
Let the bike idle for a few minutes, preferably with a cooling fan blowing.
After the couple of minutes hit the kill switch.

Let the bike cool and pull your plugs. You only look @ the TOP 1/3 of the insulator. The ideal color is like a human's dark summer tan. Black is too rich and white is dangerous to the engine.
The mixture screws are brass & fragile so be carful not to strip them.
IN(clockwise) is Lean
OUT(counter) is Richer.
Once the plugs all look good START OVER.

ReSync and ReDo the "Plug Chops" as one will affect the other.

Once this is mastered You can start doing 5k plug chops.
You pay attention to the Middle 1/3 of the insulator
After that 5K is mastered, you move to the WOT plug chops.
Then you are looking at the bottom 1/3 of the insulators

 

When I say half the porcelin I mean one side..not top to bottom. Half is white the other is light tan.? I don;t have a yics tool for syncing either...

 

MAKE one
Either the metal kind
OR
Do what I do.
Cut strips of cotton t shirt
Knot them together.
Soak in Marvel Mystery Oil.
stuff using a dowel of some kind.
replace the bolts on the ends and your yics is blocked.

Just make sure not to overheat,
SEE SMOKE, STOP!

Does your plug look like #1?
http://www.xjbikes.com/Forums/viewtopic/t=10958.html

 

You didn't take out the AIR Jets and get them confused, did you?
The AIR Jets are under the Diaphragm Rubber.
Two of them:

Air Jet Placement:


You got something clogged if you are out at More than 3 Turns and you are still running Lean.

Do an AIR LEAK Test. Turn on the gas of your Propane Torch.
Don't light it.
Probe around the Manifolds and Boots with the Gas and listen for a spike in rpm's.
If your rpm's rise ... you have a leak.
But the Leak will only affect the Cylinder that the leak is on.
If all your Plugs are still too white. The Pilot Fuel isnt coming up.

 

I did the air leak test and nothing..I double checked the jets..they are fine. I snyced the carbsused a slightly smaller cotton laundry line with knots and MMM(vacuum type) all within spec. Went for a ride...Now the lower half of the plug is black(soot) upper half is white? They are all turned 2 3/4 out now...

 

Forgot to mention that inside the YICS port is wet with (I think) oil?

 

Is there PODS/K&N Filter or aftermarket exhaust?
Describe, in EXCRUCIATING DETAIL, how it is running.
All the way from 1.1k to 9.5k

The "bottom" portion of the insulator makes no diffrence unless your tuning in your Mains.
The top 1/3 is where your idle is read.
Increase rpm and the idle section burns off all soot and the next 1/3 section starts telling its story.
When you nail the idle circut, start worring about the middle.

 

You can clean-out the YICS Passage by pushing Carb Cleaner soaked patches right straight through ons side and out the other.
Just remove the Plugs from both sides.

Have you done Plug Chops?
Do you know what to do to get a read on the Plugs?

 

I did plugs chops last night and am getting soot around the bottom of the plug threads and white insulator. Did a 5000 10 min drive and cut engine at side of the raod and pulled the plugs. As far as running...it seems to run great no hesitation, no backfiring, no bogging. Just smooth roll on power and a lower note from the exhaust. As for pods etc... All stock...stock jets..stock air filter(new) uni..and stock exhaust..Baffled here. As for the enrichment tubes. I conceded they must be clogged because I can tell a few are working. The r's come up to about 1500 instead of 4000 like they used to..but it almost dies when I put the choke on..So off goes the carbs again I guess.

 

Are you running the right Heat Range of Plugs?
You might be getting sooty because of Valve Seals.

If you are Pulling the Carbs, again ... make sure all the Air Holes on the Emulsion Tubes are clear and clean.
Set the Diaphragm Pistons on a level straight edge and make sure the needles are all at the same height.

If the Insulators are all clean and white, you need to add some fuel to the Mixture.
Bring the Pilot Mixture Screws out a bit, and keep an eye on the Plugs.

Be sure you haven't got air leaks.
Air leaks will lean you out in a big hurry.

Lets see what happens when you add some Fuel to the Mix.

 

Ok I've had it, enough with this bike! I can't get it to do anything but either white plug or in the case of cylinder #4 half white/ half covered with black soot...I think I'll go back to the Honda and forget about it. Too bad really because it runs so well. But if I keep driving it in this lean condition, it will have major problems. I have had the screws out to 3 3/4 now which in my opinion is way too far. When I turn them in it does die on the cylinder like it's supposed to, and it does increase the rpms going out on all. I checked for vacuum leaks with every method i could think of to no avail ??????????????? AARRRGH!!! WHAT THE FETCH!!

 

Re: Here's a brain teaser, White plugs and choke not do much

Conventional knowledge is telling us that there is SOMETHING NOT RIGHT with the Pilot Mixture System.

We go the Square-1

Are they the right sized Pilot Jets?
Are the Jets clogged?
Are the Passages clear?
Are the Main AIR and Pilot AIR Jets in the right position?
Are the Pilot Mixture Screws installed correctly?
Screw, Spring, Flat washer, O-ring?

Are the O-rings seated correctly?
Are the Pilot Mixture Screws OEM Stock or Aftermarket?

Did you flush the Passages with the Jet and Screw out?
Are you running the right Heat Range of Spark Plug?

Test the Pilot Mixture System.
Go to a Drugstore and get a Rubber Ear Syringe.

Ear Syringe:


Using the Ear Syringe ... test the Pilot Jet Flow on each Carb.
Evacuate the Syringe.
Place the Nose of the Syringe in the Pilot AIR Jet and try to suck-up some Pilot Jet Fuel Supply.
If you get gas in the Syringe ... OK.
No Gas? Clogged Pilot Jet or Passage.

Fill Syringe with Carb Cleaner.
Place nose of Syringe in Pilot AIR Jet.
Flush passage.

Test run bike.
Test run bike with external Fuel Supply.
Starting Fluid sprayed in airbox.
Unlit Propane Torch played in airbox.

 

To answer
1. yes
2. no
3. yes
4. yes
5. yes
6. yes
7. yes
8 OEM
9 yes
10. This one I have a question about, I'm using the correct plug called for by the manual..BP7ES..Is this the right one for the 750 that you know of? Is there a cooler plug for this bike? This might be the problem I guess If the manual is wrong. ?? I'll try your method with the ear syringe too...

 

I did plug chops stationary in the garge at 5,000 rpms's @ 15-20 seconds. Doesn;t seem to be enough to clean the soot from idling off of them. Maybe I should get a fresh set of plugs and start over? I tried all of the measures that were suggested and all posrts on bike are clear. Now #4 is partially sooty and other plugs are light tan on one side of the porcelin like it's hotter on one side of the plug than the other. This is a 82 xj750 which is supposed to have a self tensioning cam chain? I hear what sounds like cam chain noise so I would love to be able to adjust it. I see the customary nut and bolt for adjustment so why is that there if these bikes are self adjusting? I read in the manual that if I mess with it I will have to replace it?