XJ700 won't go under 5,000rpm

I got the carbs "zestfully clean" and put them back on. Now the same bike that wouldn't run at all starts great, but climbs up to about 5000rpm and stays there. I'm pretty sure the jets are in right, the choke is let out and the throttle is let out completely, but every time I start it, it goes up to 5000 and smokes a lot. What else can I do to slow it to the correct idle? Is there an idle screw that I'm not aware of? I checked the fuel level in the bowls and its right, if not just a little low. It sounds smooth, and responds to the throttle to ge even faster, but it just won't slow down. Any ideas?

 

Okay, I'm not that stupid. I just realized there is an idle screw that I even tried adjusting before I took the carbs off to begin with...I'll start there and see if that's the reason for the super-idle.

 

The idle speed adjustment is a knob that sits between the #2 and #3 float bowls.
Did you bench synch the carbs?

 

"smokes a lot" would be more of concern to me than the idle issue. What exactly do you mean by "smokes a lot?"

 

I'm assuming (wrong I know) that it's just oil burnoff from sitting so long. Rings might be sticky. But.......

What color smoke?

 

Okay, so I adjusted the idle screw to lower the speed and it did, but I can't seem to make it stay where it should. I've been running it for a like an hour now to warm it up and see if it would level out, and all I get is either somewhere around 3000-4000rpm or dead-if I turn it down even slightly from where it is at 3000rpm, it slowly goes down until it dies.

 

And the smoke was white, but it stopped happening for the most part now. After like 20 minuets of running, the smoke stopped happening- now its just the idle thing. I had put a lot of seafoam in before, so I'm assuming its all gone now.

 

is your throttle cable to tight. mine was after rebuilding the carbs, slacked it some and idle dropped to where it should be

 

Throttle cable is good, I checked it first as well as the choke cable.

 

So getting back to K-moe question, did you bench sync the carbs?

 

Let me exapnd on the reason that I asked. During the bench synch it is possible to get the idle control knob set to where the throttle plates will never fully close.

 

I'm not sure...I didn't spend a lot of time on the bench sync because they were already the same. I basically just checked them and they were all the same.

 

Something is holding the revs higher (air leak, binding butterfly, poor sync). I'll start shooting from the hip now

Are all the vacuum caps on the intake manifolds and the vacuum tube from one manifold (not sure on the 700s, but usually from cylinder 3) connected to the petcock?

Is the throttle cable end seated properly in the holder?

Foreign debris holding the butterfly open?

Did you 'reset' your mixture screws at all?

 

Does it sound like its running on all cylinders? I had an issue with my 700 after this winter where it wouldn't idle well and shot some " smoke " out the exhaust. Adjusted the idle screw a bunch but could never get it to stay the same on the next run or if it warmed up or cooled. One day I was sitting in my garage thinking next to my bike and started checking the terminals on the plugs, as soon as I touched one the bike revved up and idled about 500 rpms more. I suddenly realized the connection to the plug was loose and the cylinder wasn't firing every time. The " smoke " was the unburned gas/air. After adjusting the Idle control I have had no issues and the bike sits firmly at 1100

 

i really hope you have a strong fan blowing on it

 

are your valves in spec....?

 

I have all the vacuum caps on... #3 didn't have one so I used a piece of vacuum line and shoved a pencil in the end to stopper it. What was that about another vacuum line coming out of number 3? I have a metal tube thing coming out of number 3 that comes out at an angle and then points straight up, so I'm thinking I made a mistake... Earlier, I removed the can thing that mounts to the right of the battery, just behind the right side cover. I took it out when I took the carbs out and left it out when I put them back in because:

A- It seems pretty worthless;
B- Someone said the charcoal from it can get into the gas tank and clog up the carbs;
C- It leaves a cup holder behind to put stuff in a very convenient place on my bike, which I couldn't be happier about.

So, when I put the carburetors back in I saw that extra metal tube coming out of #3 and capped it off (the same way I did with the manifold vacuum line that was missing a cap) because I didn't know what its purpose was and assumed it had to do with that stupid charcoal can thing. So is that supposed to go to the petcock somehow? I do remember there was an extra little port thing on the petcock, but I haven't been using the gas tank because I think someone put sand or more likely salt in it (because there was a whole lot of something in the carbs) and I haven't rinsed it out yet. (I'm assuming I can just put a bunch of gas in it, swirl it around and pour it out a few times to clean it?) So, to test the carbs, I've peen feeding gas right into the carburetor fuel inlet thing by using the fuel hose that was on it before, then a fuel filter, then another fuel line (the one that went up to the gas tank) connected to a funnel...and I've just been pouring gas in the funnel till it fills up and running the bike.

 

The valves are good- that was the first thing I checked before I went to the carbs.

 

Before I cleaned the carbs only certain header pipes would heat up while running the bike, but now the all seem to heat up. Some are hotter than others, but the engine sounds good- if I were constantly revving it up.

 

A- It is an emissions canister and helps you to have cleaner air to breathe.
B- That someone has no clue how the canister works.
C- Cup holders are useful

D- The port for the #3 carb manifold is supposed to connect to the vacuum port on the petcock, otherwise the petcock will not flow fuel in the ON or RES(erve) positions.

E- You need to get a copy of the service manual and examine the vacuum line routing. You have a vacuum leak somewhere, and the lines are now suspect because of the canister removal.

F- E nothwithstanding you may have a vacuum leak elsewhere, but it's pointless looking for it until item E is addressed.

 

It was like 20 minuets of on and off running- I didn't keep the engine revved up to 5000 for 20 minuets straight haha

 

Like another member mentioned you may not be running on all 4. I had a similar problem like that with my bike and the spark plug gaps were way out of spec I had a funny idle like that when not running on all 4

 

It has new NGK plugs, gapped to spec

 

Have you confirmed spark on all cylinders?

 

Yep, each one sparks great when grounded to the engine case and started. However, when I took the old plugs off I noticed that they had the little top nubs removed to expose the threaded end for a screw-on boot, so I removed these nubs from the new ones too. Are these supposed to be like that? I tried putting the boot on one with the nub thing still on, but it wouldn't fit so I assume the boots are supposed to just be pushed down onto the threads without the nub thing. Can anyone confirm this?

 

Yep, that's how it's supposed to be. Sounds like the problem lies in how that canister is or isn't connected (is that california emissions gear or something?). Any chance you can get some pics of the petcock and carb area? That being said a manual might help in this situation.