Carb prob. Engine runs away

Ok guys, heres the deal. I took the carbs off to fix one problem and made another.
82 xj 650

My bike was hard to start and required ether to start and after words would be fine. so I figured my enrichment tubes needed cleaning again. (2 seasons ago I tore the carbs down to parade rest and rebuilt them via Ricks thread). So I yanked the carbs off, bowls and hats. Enrichment circuits looked fine. So I did all the normal stuff, sprayed all the little holes clean, made minor adjustments to the float levels, clunk test, bread tie bench synch, etc...... basically i didn't really change anything.
Put the carbs back on the bike hooked up the linkage, hit the start button and vrrrrrrrrrrrrrrrrrrrrrrrrom bike idled away around 5K. yanked the throttle back a couple of times to get her to calm down and she "slowly" came back down to an idle. now ever time i hit the throttle she idles away and slowly climbs back down..... I tore them back apart thinking i must of put something together wrong, put them back on the bike and tried again. Same thing. Would somebody please help me figure out what silly little steps or thing I'm forgetting to do here.

Thanks,
completely frustrated in NC

 

First make sure you didn't mix up the choke and throttle cables.

Then make sure your throttle closes all the way and the cable is not binding.

Then try turning the main idle speed knob in between #2 and #3 out to bring it down to idle. Then check for air leaks.

 

Check for leaks. Make sure the throttle and choke didn't get switched. Most likely...you bench synched, which can get the butterflies even...but you might have opened them past idle position. Try adjusting the idle speed screw down (counter clockwise).

 

Cables. checked
idle. checked

torn them apart again found the main needle on 3 was pulled out past the shoulder. took the big plastic allen nut off the back. reseated then needle in the plastic groument. getting ready to put back on the bike and see if it makes a differance.

 

Ok. Put them back on bike. Same problem. Now I got them hanging on the rack with the test tank hooked up. Gonna let them sit for a couple of hours to make sure they are not leaking.

Keep firing of suggestions. Somebody is bound to come a crossed the right suggestion.

 

Did it come down by turning out the main idle speed knob?

IF they're leaking fuel it should flood and die not race.

Either your throttle blades are open too far or you've got a bad air leak or both.

You cannot get above idle with the blades closed and no air leak.

 

When I take the carbs off. the boots on the engine side are wet. Flooded. When I run the idle down. Its a quarter turn difference between racing and dead.

 

Mine idled at 5-6k rpm on choke when it was sucking air on one intake gasket...

 

No air leak either.
Did the propane torch around the boots. Even sprayed em down with wd 40

 

Then you have partly open throttles and leaking fuel.

 

I can get it to idle. Put the ycis tool in an snych. Color tune. How 9 yards. I touch the throttle and she races away. Throttle cable is routed right and snaps right back to close position. It races away. Then slowly returns to idle. Throttle seals maybe? But what is weird is I took it apart for an unresponsive choke. Just cleaned her up an put her back together and now its runing away like she's way out of synch. But I have the sticks on her and she's good. Some how she is drawing too much fuel from some where.

 

Holed diaphragm, slide not returning fast enough?

 

Healed the diaphragms up to light. And no pin holes. Slides passes clunk test. Maybe I'll polish them again tonight for the heck of it. Aint like I got anything better to do till then.

 

Also make sure the diaphrams seat completely in their groove. You can get an air leak there if not.

 

I'm now an XJ wizard! Do I get a cool wizard hat or something? {quote}

So is Schooter, work it out. ;o)

 

There's not two, or more, hats?

Maybe I can trade him his wizard hat for that maxim wheel he wants.....

 

Ok guys I got completely agitated by my lack of ability to get my carbs right. So I took a set a junk parts carbs that i got of a parts bike that head been laying under a tree for years and gave it a good deucing out slapped them on the bike and BINGO! It fired right up and purred like a kitten. Sigh _ it works great but they are ugly on that bike. New throttle seal are on their way now for the pretty carbs. just goes to show yeah that it can be the little things.

 

OK guys Ireally am out of ideas now and need some help. As I said in a previous post, the parts carbs worked great. and my good carbs would make the engine Idile away around 5-6K. So I just got my new throttle saft seals stripped the carbs down cleaned, cleaned and cleaned some more, Gosh they are pretty now. went through Ricks "the whole 9 yards again" pretty easy as these carbs have been through that before. and after about 4 hours worth of hard work, I proudly put the shiney carbs back on the bike complete with the new throttle saft seals , Aligned, cleaned, clunked, bench synced, floated checked, and yes the tab on the diaphram is in the right place, cables connected correctly, etc. hit the choke, turned the key and it would not light. I needed to hit it with ether to go. got it running and she would not come down unless the choke was on, heck i had the idle screw almost pulled completly out. So I started trouble shooting. trying to think what the heck was different between the parts carbs and the shiney ones. So I swapped out the fuel bowls thinking maybe I might of widened that little orffice in the bowl while using a tiny wire trying to get carb cleaning through it. back on the bike, and same thing. so next a swapped out the slides and slinky, thinking maybe I had some tiny pin holes that I missed while checking them under the light. back on the bike and same thing it wont come down below 5K. So the only diffference between the part carbs and mine is the bodys right? but as I explained in my first post the original the orginal good carbs where fine other then I was not happy with the way it was starting. so all I did was pulled them off sprayed them down check the emulsion tubes and put the back on the bike and this problem started. I can elimanted the possiblitly of an airleak around the boots becuase the other parts carbs work fine. So I'm open to suggestions now. please fire away.

 

Are your butterflys closed all the way? Were they bench synched?

 

they were bench synched with a bread tie wire, and checked them over a light. when I back them down after synching they all completlety close.

 

your getting too much fuel either float level is to high or you put the jets in the wrong holes. One of the manuals shows the jets in the diagram wrong I think its the haynes but im not 100% on that.

 

Floats are 3mm below the rim. off to the garage to check jets. anything is possible at this point.

 

Can you take a picture of carb without the bowl. When you say floats are 3mm below rim did you mean fuel level?

 

exactly. hanging on my level carb rack with a fuel line connected, bowl drains cracked they are 3mm below the top of the bowl. I'm gonna try to reset the butterfly valves now. Its got to be there. i bet you originally i had a throttle seal problem. and now i bet i have a valve mis aliinged. with the idle screw completly backed of the only fuel I should be getting is through the pilots right?

 

Are your floats in upside down?

And the Haynes has the air jets under the diaphrams wrong.

 

start with your pilot (idle) mix screws 2 to 2.5 turns from bottom and tune from there. Not all the way out.

 

thats correct unless the choke is on

 

The only other thing I can think of and i am not even sure it is possible to do it is the parts that attach to the rod that raise the brass enrichment dodads are installed upside down. I mean I think youve covered everything at this point

 

Floats installed upside down? (don't laugh, it happens)
The Haynes manual does show the jets in the wrong positions, be sure you have the big jet (110) in the main position and the smaller 50 in the pilot position.

 

welp. I see one possible issue. i have 205 on the mains. but i have 2 other carbs on the bench that have 205 in them also and i have never replaced jets

 

also I dont have the haynes manual. I have a efile of the yamamha service dealer manual . botom line my manual shows the pilot to go towards the choke rail. yet i have the main installed on the choke rail side. which way should it be?

 

Main Air jet goes over top of the main fuel jet in the center. Pilot air jet over pilot fuel jet toward front of bike.

 

Ok when you say 205 on the mains is the 205 air jet installed where the main air jet goes or where the pilot air jet goes?