Carb trouble

So I was pretty confident when I went to put the carbs on today. I thought they would start right up!

Unfortunately, they didnt. The engine would turn over and it didnt give the slightest impression that it was trying to fire.

It started and ran for a little bit on starting fluid but it was kind of erratic. (As a note for this, I hadnt noticed until after it died that the choke was all the way up. So I think that may have had something to do with it.)

I looked up some forums, but all I really saw was those who put their floats on backwards. I know I couldnt have done that. I made sure to double check the fuel levels before I put the carbs back on the back. After the last time I checked, I didnt even open the bowls.

So I am thinking it might have to do with the air/fuel mixture screws. I took them out and cleaned them and put them back to where they seemed to be before. Could this be the culprit?

 

I dont know if this would help but, I put a clear inline fuel filter on just so I could see if gas was flowing at all.
It comes in handy quiet a bit.
Good luck.

 

Put a rag under one of the float bowls and open the drain plug...this will tell you if your atleat getting gas to the carbs.

 

I might also be pretty low on gas though. Gas is at the bottom of the tank.

 

Did you bench sync?

 

No, I didnt mess with the synch screws at all.

 

What did you do to the rack? It's relatively easy to screw up your sync inadvertently. A bench sync will at least tell you if you're close to begin with.

 

Like as far as cleaning? I went through and cleaned everything, made sure all passages were clear. Polished up just about everything, including the slide bores. I didnt take any of the carbs off the rack. I spent a lot of time getting the float levels adjusted just right. I didnt touch the synch screws since everything seemed pretty even. Im beginning to wonder if I am just out of gas.

 

google gas stations... map quest is good too...

 

when you had the mixture screws out....did you remove and inspect the o ring that the needle seat to? When you re-asemble the o ring goes in first, followed by the spring seat washer, tension spring and last the mixture screw.

 

Lol, Bill I found one that is 20 yards away!!! What are the odds????



Ya, everything seemed pretty good, I assembled it all back the way it came. If the fuel-air screws were way off, would it cause it not to start?

 

Just set the mixture screws 2 1\2 turns out to start.....have you checked to see if you have fuel in the float bowls?

 

No, not yet. I will probably do all this tomorrow or Saturday. Ill keep you guys informed.

 

So I am pretty discouraged.

It never seems to fail that something always messes up.

I put gas in it today. Needed to start with starting fluid. But after that it seemed to start ok. It would idle pretty high, like around 2500. Adjusting the idle speed knob did nothing at all to change the idle rpms. Whenever I used the throttle, the rpms raced up to 4-5k rpm and stayed there for a second or two and came back down.

After it raced up and I shut it down. I tried starting it again. All I heard was a click on the right side and then I could get anything as far as turning over. No click, nothing. Only silence. No busted fuses.

On top of everything, I scraped my side cover pretty bad...

Help!

 

You need to sync the carbs is all.

Its a simple process and it should get those rpms down to normal AND make it run decent enough to keep your hopes up till you decide to REALLY turn up the heat and do some fine tuning.

This is the link to the sync tool i use

http://xjbikes.com/Forums/viewtopic/t=25482.html

 

Agreed. Sounds like classic out-of-sync behavior. (When it's running.)

The sudden loss of everything power-wise is probably nothing more than a flaky sidestand switch or the OFF/RUN/OFF switch needs to be "woke up" (cycle it back and forth a few times; if it has a "hitch in its git-along" then you need to take it apart and gave a peek, do some cleaning, etc...)

You should probably read this: http://xjbikes.com/Forums/viewtopic/t=24010.html It's philosophical not technical.

The reason "something always messes up" is because your bike is controlling the process right now; you need to regain control is all.

 

Well the main problem is that I cant get it to turnover now. Any ideas?

 

can you elaborate?

 

Well I think that is solved. The ignition fuse didnt seem like it was making good contact. Now its starting. I will probably do that synch. Bill can you walk me through your process?

What comes first? A synch or colortune? Or does it not matter?

 

If you just want to get it running half way smooth a sync will get you started.
(you will need to fine tune it later.. sooner than later)

Just prop the tank up a little so you can get a screw driver on the sync screws.

Attach the tubes to the 1 and 4 carbs. (after you have it running awhile... put a fan on it so it doesn't get too hot)

Fire up the motor and turn the sync screw on 1 until the oil in the tube is even.
( its not simple your first time through but you will get the hang of it )

Shut the engine down. Remove the tube from 1 and put it on 3s sync port.
(put the 1 port cap back on.)

Start the motor again and repeat.

You may have to fiddle with the MAIN idle screw behind the carbs to keep it running during all this.

Look back on here in a bit for a few more tips. Others will chime in soon.

 

Well its starting up every time. But its running really lean, I put a colortune to it and only did the outer two. The one on the right would not go blue, the one on the left did. I dont have the carbs hooked up to the airbox right now because I was wanting to see if the floats were sticking or not.

Its still idling pretty high, around 2k. Every once in awhile the rpms race up to 5k or so before i shut it off. Its as if the throttle cable is getting stuck. Trying to adjust the idle mixture knob is still doing nothing at all. It almost seems like where the throttle cable hooks into the carb linkage has something wrong. If I press down on the linkage, the idle drops down and it runs smoother. Its like the carbs are open more than they should be right now.

 

A member on here suggested covering the carb intakes with a rag
Because he didn't have a airbox. I'd try that to see if the idle comes down but you WILL need to do the sync.

 

I thought the colortune came after sync THEN fine tuning
by looking at the plugs individually to adjust the mix screw
for the perfect color (brownish).

 

Clean Carbs
Bench Sync
Install Carbs
Install YICS Tool
COLORTUNE The IDLE Mixture's
Vacuum Sync
REMOVE Tool

Re-ColorTune Idles w/o Tool
Plug Chops
Individual Carb Tweak

 

Well I dont have the YICS. I have had rags off and on covering the carbs, doesnt seem to make a difference.

 

do the running sync... It should run 10X better providing you have the air box and filter.

 

Alright, I didnt think it possible for it to be that much out of sync. It always seemed to run somewhat properly before? But I did plan on doing it anyways.

I take it I am syncing the carbs to the number 4 carb?

 

The worst part of all of this is I dont have a garage. Since I live in an apartment, I have to make do. Im feeling better than I was yesterday about the whole situation. I think I will just have to take some time on a running sync and not let things get too hot.

 

Number 3 is the default carb, the other 3 get matched to that one.

 

Wizard,
What order do you use?

 

If you have a state of the art carbtune, you just adjust the screws untill they all line up. Me, with my single gauge, take a reading off 3, then match 1 to 2, then 4 to 3, then 2 (inc' 1) to 3 (inc' 4).

 

Found a couple of videos on this

http://www.youtube.com/watch?v=0nKaGEMLZjs

http://www.youtube.com/watch?v=nEE508Wz ... re=related

Question for you guys; What diameter tubing will I need?

 

The guy in your video states 8 mm, sounds right.

 

The hanging idle could also be a sticky slide. Do the 'go clunk'? The other thing is make sure your throttle cable is routed correctly and isn't hanging.

edit, also, make sure the butterflies snap back closed with no hesitation. You may need to hit the butterfly springs (sorry, I don't know the formal name) with some pb blaster or wd and work it in

 

Ya, I know they passed that clunk test. I worked on those slide bores for quite some time. The butterfly springs might be a little stiff after going through a wash. Ill see if they are sticking or not. Does anyone have a picture of a throttle cable hooked up correctly?

 

You should balance 3 (the reference carb)~4 then 1~2 and finally balance the two sides to each other with the middle sync screw.

 

I hooked up the manometer I made to the carbs today. On the 3-4 I could not stop the 4 carb from having more vacuum. I was able to balance 1-2 and than 1,2-3,4 but its not down completely right. The problem with trying to adjust the synch is the idle fluctuates frequently. One minute it will go low and sound pretty good, and the next minute the idle jumps up again and the vacuum changes. Its as if the carbs are pulling different amounts of vacuum periodically. So to describe a little more. I will get it balanced, and than one carb will seem to draw more vacuum.

I am still having the problem of having the bike run up to 5k rpms whenever i blip the throttle.

Im stuck in a rut you guys!!! Can you help??

 

You're getting some unwanted air in there.

 

Probably obvious, but I should have them hooked up to the airbox right?

 

Yep..and check th clamps on both sides of th carbs are located correctly and done up firmly.

 

Alright, will do.

Any ideas as far as the rpms racing up to 5k?

 

Ok doesit do it on its own or after you blip the throttle.

I had a set of carbs that were hanging up do to an alignment problem with a couple of the throttle blades not centered properly after I changed the throttle shaft seals

 

Usually when I blip it. Im not sure if it really does it on its own. I dont think it does.

What exactly are the throttle blades?

 

When you have the carbs off and you look in the engine side. You'll see the throttle blades open & close when you move the throttle shafts

 

That may be a problem. I did take the throttle blades off to make sure they were clean. How can you make sure they are centered?

 

I install them losely in the bore, with the screws just tight enough to hold the blade in place. I then unscrew the screws about 1/4 turn and cycle the shaft several times with the blade loose. They will usually center up, provided you do this gently. Once centered, I will tighten up one screw and remove the other to apply Loctite. Once I get that screw back in place and tightened, I pull the other and repeat.

 

Robert, I think you solved my problem. I took a look at them today, and I worked the linkage slowly like you said (before loosening the screws) and It would stick open a little less than half way. I loosened all the screws and sprayed some WD40 on the springs and linkage assemblies and now it seems to open and close very easily. Ill tighten up the screws, throw them back on the bike, and hope for the best haha.

 

I'll hope with you! I can't wait 'till you hammer this whole carb thing out and get it rolling happy! You have certainly earned it.

 

oh no you dont raven!!! you better not fix yours befor i fix mine!!! nnnnnnnoooooooooooooooooooooooooo!!!!!!!!!!!!!!

 

Haha, I think I may have already beat you!