XJ600 exhaust "bubble", rough idle

[Cichy92]

Hello
I have some trouble with my XJ600. When bike idle, left exhaust have tendency rev up (from 1200rmp to 2000rpm especially after warm up ) and bubbling exactly like a car in yt link below.
I cheked the temperature of mainfold for each cylinder. First one had less temperature than others, it was warm but not hot.
I checked and swapped coils, intake rubbers and spark plugs but nothing really changed, first mainfoild still colder than others.
All carburetors have same pilot jet number of turns out - 2, like manual says.
I can't figure it out.
If that bubbling means the first cyliner has too much or less fuel?
https://www.youtube.com/watch?v=KKXOAWyCV7A

[Nobby the Bastard]

Check the wiring from the tdi to the coil.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[Easy-X]

squirt, squish, spark, bang

9 out of 10 times you're missing a spark (as Nobby suggested) so check that first.

If you turn it over a bit you can also give the plug a sniff for fuel when you take it out to test the spark. (Take out one of the others to compare if you're still not sure.) A dry plug would hint at a fuel supply problem (either to the carb or the carb itself.)

If spark and fuel is good I'd do a compression test. Easier to get one of the gauges for that on a multi-cylinder engine. Compression down might hint at a valve problem.
____________________
Royal Enfield Continental GT 535, Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Nobby the Bastard]

Suck, squish, bang, blow...
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[Easy-X]

[Cichy92]

[jaffa90]

""""When bike idle, left exhaust have tendency rev up (from 1200rmp to 2000rpm especially after warm up )""""?????????????

I do not understand that!

When were the valve clearances checked?

Also what did the spark plugs tell you?

[Cichy92]

[Bhud]

Possibilities are:

- Running lean (engine needs less fuel when hot)
- Vacuum leak somewhere
- Carbs out of balance
- Electrical problem: intermittent spark means fuel-air mix isn't always being burned in a cylinder but instead gets thrown down hot exhaust system.

Diagnostic method first, solution later.

Step one: take out spark plugs, examine and report.

[jaffa90]

Does this bike have a vacuum petrol tap with a pipe going to the said left cylinder?
Could be the choke not shutting off properly or varying fuel level in the float chamber/s.

Also my last post?

[Cichy92]

[temeluchus]

Is it a carbed diversion or pre diversion XJ600 or a fuel injected watercooled divvy?

Assuming its the aircooled Diversion XJ600, I would suggest:

-Remove the fuel tank
-inspect the balancing ports on the inlets and make sure they are all blanked off
-remove all the plug caps and make sure neither the caps or the end of the wires are corroded
make sure the airbox is securely fitted and the tubes to the carbs are secure
-before you refit the fuel tank, drain all four float bowls. Water in the fuel can cause this kind of spitting/farting nonsense.

Once thats done we will have more to go off of.
____________________
Some shite cruiser. Now with guns and FREEDOM!

[jaffa90]

""" Yes, when im disconnecting it engine starts choking and rev going down. """

Does this vacuum pipe smell of fuel?

[Cichy92]

[Easy-X]

Wait... mis-fire on idle? Pilot jet blocked on one carb?
____________________
Royal Enfield Continental GT 535, Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[jaffa90]

[Bhud]

[Cichy92]

[Bhud]