Bike wont Rev up

I have an 82 xj550 that just wont run right please help me...

last winter I forgot to put stabilizer in the gas and the bike sat for 2 months so I drained all the gas out took the carbs apart cleaned them up installed new fuel filter and put everything back together and filled with fresh gas. Now the bike starts fine idles good but as soon as it heats up the plugs get flooded and you cant give it gas or it dies.... i turned the mix screws in almost all the way but it still runs rich and the plugs are full of black carbon.....

Is this still a carb issue? should I soak them in carb cleaner for a few days or should I be looking somewhere else?

 

check your float levels.....

 

If you just cleaned the carbs, the floats shouldn't be sticking. How's your petcock? If it's leaking, that could be the problem. When you cleaned the carbs, did you set the float levels properly? It's a hassle but it has to be done.

 

I haven't adjusted the floats at all I just took them out cleaned and reinstalled, they seem to be working fine as far as I can tell.

 

Well i've been looking in to this and I'm going to change the needle and seat, adjust the float level and see how she runs...

 

Ok so I had to set the float levels because they were way off...I guess that was one of my problems but It still wont take any throttle. It will start everytime but as soon as you give it some throttle is starts to bog if you let off its fine but if you try to floor it it will stall. It takes no effort to start right back up, no choke or throttle needed. After you let it idle and get really warm it gets worse, If you feather the throttle up when its could you can get it to rev but as soon as its warm you cant do anything but idle.


I'm going to start checking all my wiring now I think I might have a bad ground or conection......

 

If you didn't knock-out the Center Main Fuel Nozzles ... also known as Emulsion Tubes ... that would be the first place I'd go looking.

Since you have to pull the Carbs off and take them apart to look ...
I'd clean them thoroughly and Polish the Diaphragm Bores.

Pull an all-nighter
Get them done all in one sitting.

Cleaning Bores with ScotchBrite Medium:


After additional POLISHING work:

 

and make sure your floats are set. cuz it sounds like they aren't.

get all your information handy. cuz i bet i took mine apart 7 times with everyone suggestions on this sight before i finally got things squared away that had nothing to do with the carbs. cept for my last screw up. ROFL.

 

If you think the Carbs are cleaned well enough to be tuned:

Get the Bike to IDLE with the Throttles Closed.
You need fans and an auxiliary fuel supply.
Plug the Vacuum Line with a Golf tee when you remove the Tank.

Be a Tweaker.
This is “Real Old School Tuning”
By “Ear”

Start 2.5 ~ 3 Turns OUT from bottom on all 4 Carbs
For 750 Bikes I’d set them at just between 2-3/4 & 3 … closer to 3
Put two drops of light Oil in each Pilot Mixture Hole'

Important:
Make yourself a screwdriver that fits the slot on the Pilot Mixture Screw with Precision. Even if yours are loose and won’t bind … you want to be able to “Feel” the Screw moving. If they aren’t loose an ill-fitting screwdriver will destroy the slot, causing a big problem!

Above the Starter Motor ... Under Carbs 2 & 3 is the Idle Adjustment Rod.
It has a Thumb Wheel on the end. Oil it.
You’ll need to be able to make highly precise adjustments without difficulty!

Turn the Idle Rod Clockwise a tiny bit at a time until the engine is running steadily.
Don't exceed 1,200 rpm’s (1,050 if you can get it. 950 if the Tuning permits)

While the Engine’s running.
Begin the Tweaking.

Turn the Pilot Mixture Screw for #-1 OUT ... real S-L-O-W-L-Y.
Listen for the RPM's to INCREASE.
The revs should rise as you give the Mixture Screw turns out for more Fuel and Air at the Pilot Screw.
This is Pilot Mixture for Idling.

Listen to the Engine very intently. The rpm’s are about to change.

When the revs rise here’s what to do...
Keep the RPM's at 1,100 by reaching under the Carbs and lowering the Idle Adjustment Knob. Stay close to 1,000 rpm’s at all times.

"Tweak" OUT ... the #-1 Pilot Mixture Screw listening to the Engine and Exhaust note VERY Carefully.

Keep turning the SCREW ~> OUT if the RPM's continue to rise.

At some point ... The RPM's ~~> will NOT continue to rise.
Remember this Point. You have to come back to it.
At THIS point ... MICROSCOPICALLY continue the Turning OUT...

UNTIL <~~

The Mixture gets TOO RICH and the Bike:
Coughs
Misfires
Burps
Runs rough
Etc.

>> STOP <<

THEN <~~
Get ready to make a CRITICAL Adjustment.
Pretend you are about to move THE SECOND HAND on a STOPWATCH!
One FULL Turn would be 60 Seconds ... right?
OK.

Turn that Pilot Screw ~~> IN <~~

Two (2) Seconds ... maybe Three (3) (Seconds, small, a (my-nute amount)
Don't go too far.

Run fans to keep the bike cool.
Throttle it up and let it idle.

Constantly Adjust the IDLE rpm's with the Idle Adjustment ROD.
1,100 Max while Tweaking.

Tweak #-2
Just exactly like #-1

(If the rev's exceed 2,000 ... back-off the IDLE SPEED ROD More)

Then finish-up doing #-3 -&- #-4.

When you are done ... TWEAKING ... you will need to Road Test for THROTTLE RESPONSE.

IF...

You are Idling, say, at a Red Light and when the light turns green and you take-off ...
(Getting “Out-of-the-hole”) … and, …

The Bike ~>
BACKFIRES a little bit before the Power comes on:
Your LEAN
The Pilot Screws need to be:
Tweaked OUT
Two (2) Seconds.
Chart where you are at from this moment on … +2 Seconds

IF...

You are at the light and take-off...
The Bike ~>
HESITATES for the slightest bit before the Power comes on:
Your RICH
The Pilot Screws need to be:
Tweaked IN
Two (2) Seconds. (Almost not turning the screw at all. A nudge!)

Fine-tuning will be complete when you have Tweaked-Out the Backfire or the Hesitation during Further Load Testing.

All further Tweaking is to be done in increments of:

Two Seconds at a time.
Go find a closed Industrial Park and do it all in one sitting.
Have somebody put the tools you need in a sack and follow you over there in the car.
Don’t forget a Flashlight.

Backfire = Lean = OUT

Hesitation = Rich = IN

Go for it!

Get Tweaked
Watch your Plugs and treat each Cylinder individually.
Read the Color of the Plug on the Center Electrode’s Ceramic Collar.
Too Dark (Beyond chocolate brown) Tweak IN: 2-Seconds

Too Clean: (Clean or no coloration) Tweak OUT: 2-Seconds
As you Tweak individual Carbs for the right Mixture …
Watch the Plugs coloration at the Center Electrode Ceramic Collar.

Clean, like New.
DANGER!
Bad. Too Lean.
Tweak Screw OUT for MORE Fuel.
Although the Bike will run superbly Lean like that … it’s a dangerous condition that can HARM the Bike permanently.

Light Tan:
Lean but OK.
This is a Power setting.
The Mixture is burning Fast making big power. You’ll have fast acceleration with the Plugs a light tan.

You must monitor the situation and keep an eye on the Oil Level.
If your Oil starts disappearing and you don’t have a leak … you are still much too Lean.

Light Brown: Normal! (Is there such a thing?)

Dark Brown:
Rich.
Most people like to have them at the Dark Brown Mixture setting.
The Engine makes good smooth power and cruises really nicely, staying cooler than the Lean settings. Protects Valves and Rings.

 

Here's what I think, but you Do need to tweak each carb like rick mentions above, I think you're starting on 2 cylinders, the bike won't rev on 2 cyl's but will fire instantly. The plugs need to be CLEAN since they've been so blackened. Feel all four header pipes with your hand while the bike is warming up and let us know what's happening

 

-it's not electrical. You still have carb issues.

-don't put your hand on a header pipe, you might get a rude surprise.

-your float levels need to be checked using fuel and the "clear tube" method, and adjusted if necessary. Dry setting is only a starting point.

-you need to bench-sync the carbs before they go back on.

 

I was just suggesting your hand on the header when the bike is cold. It'll be at least 5 mins before it'll be too hot to touch and it'll take you about 30 seconds to know if they're All firing simultaneously. Sorry Fitz JMO. Since the fuel levels have been fixed I think they caused a secondary prob with the plugs. Its the easiest check without getting too involved.