BOGS/RUNS BAD/DIES help?

yes sir will do . I missed those!!

 

So SLOW DOWN already. What else did you miss?

You're well on your way to joining the "I've cleaned my carbs 5 times" club, (of which I am not a member.)

Become a "carburetor dentist."

 

okay so got the pilot mixture screws and everything else done that i could find. the o rings were good not squishy but not hard. felt like a rubber o ring to me. Wet set the floats again. one was a hair off. bench synced. the butterflies were completely shut. I synced them then adjusted the idle screw to where a sliver of light was showing through just like the forum said. I don't know if i jumped the gun but i started her up after all that and it ran super great. but apparently i did jump the gun.

before all this the bike was bogging down with throttle and then eventually dying. Now its not bogging or dying its more like a studder. Twist the throttle a little and it studders for a second and then it takes off like a rocket. My thought was fuel mixture or something, because its like it would eventually clear out and rev up. Pulled the plugs all 4 are black as can be and sooty. also at start up it didn't just kick over and boom start up. it would fire for a second or two then start up. (the start up issue might be a low voltage from battery issue?? ill check the battery tomorrow ) Also getting a compression gauge tomorrow. what about the studder and black plugs?

 

Just now saw this post. Yes your right i need to slow down. This is the second time ive cleaned the carbs. and if i have to take em off to clean them again then.... 3rd times a charm lol. I already know im gonna have to break em down again from my previous post. Unless you say im at that easy adjustment stage (doubtful). I already went and bought more carb cleaner though.

 

will vacuum sync fixed the studder throttle/4 pitch black sooty plugs problem? i dont know where to go from here

 

You need to stop skipping the recommended steps, do everything in order like suggested: valves, double-triple checks the carbs, ensure absolutely no vacuum leaks, then you can vacuum sync and color tune to get rid the rich condition (black plugs).

Just take it one step at the time and be 100% that it is up to spec, or you will end up repeating a lot of the work.

 

thanks sektorgaz for the reply, I have done all of the recommended steps. valves,carbs triple checked/cleaned, carbs, bench synced, wet set floats. (if im missing something please tell me ) I'm not trying to skip steps, I'm only asking what the next step is.

 

Verify that you don't have any slight vacuum leaks: take an unlit propane torch and spray near the rubber carb boots and throttle shaft seals. If the engine rpm goes up you found the problem. You'll need to fix it before syncing as tuning will be difficult and inaccurate.

If all is well, proceed to sync and tweak the pilot mixtures (colortune). This should take care of the off-idle stumble.

PS: Like someone else mentioned, you have a modified bike. There's no cookie-cutter recipe when it comes to those. Here's a thread with some more pointers: http://www.xjbikes.com/Forums/viewtopic ... ories.html

 

thanks again sektorgaz,
I will check for vac leaks in the morning.and maybe proceed to vac sync and colortune.

Also i should mention last start up i noticed the diaphram slide acts crazy when throttled. Its not smooth and just goes up and down with little "jump" . i just watched a video of the carb slides on a xj1100 on the church of clean thread and the carb slides go up and down with throttle fairly smoothly. all four of mine aggressivley "jump" while going up and down with throttle. (maybe a vac leak?) if cleaned the carb slide and the diaphram's boots seal nicley in the carb hat. maybe this is normal or a sympton of a vac leak?

 

your diaphragms may not have stayed seated.... you should be able to push them up, and they come down slowly

 

I can pick the diaphragms up and the fall somewhat slowly, more smoothly then slowly. I checked for vacuum leaks and could not find anything. I did notice the carbs spitting back some gas when on the throttle. it was a fine mist but still spitting back a noticeable amount. Just enough to make a small cloud of mist when throttled.. Black sooty plugs no vac leaks. Does this mean move on to vac sync or tear the carbs down again?????????????


Edit: Along with the spitting gas, i noticed Just a little bit of black smoke out the tailpipe. I mean a little just barley noticeable when revved. I'm guessing that's more unburned fuel. Help is appreciated.

 

Are you trying to run/adjust with wide-open carbs; as in, no pods, no airbox boots/velocity stacks, nothing; just wide-open carbs?

It for sure won't work that way.

And what is your current jetting, compared to stock, to compensate for the mods?

 

No Fitz im not trying to run/adjust with open carbs. I just took them off to look at the diapragms while the engine is running. The main jets are 126 i will look at my notes when i get home for the pilot jets.

 

wow. Just looked at my notes on my jets.
Main jets 136
pilot 40

jets under the hats
225
80
no jet.

Im guessing 136 mains are way to big. I will wait for one of you experts to chime in though.

EDIT: Yes i took the bowls off and hats off to confirm.