TOPIC:

I'm having trouble figuring out what you mean when you suddenly crack the throttle open - are you saying at idle, if you quickly open the throttle it bogs? If they are mechanical slide type carbs for the 550, if you slam the throttle open too quickly i believe the piston rises quicker than the fuel/air can compensate and you can kill it. Also, if you didn't ride the bike at all and it was just idling, the bike definitely wasn't warmed up, which could also cause the issue.

yes, i can'r ride it yet, i am with a remote tank for now, no seat etc etc.
i think it was definitely a carb problem.
now she idle and i'm happy! i have just to sync (i hope to have not strange problems as before) and ride it!

sorry, my last reply about slamming the throttle open doesn't apply - I thought you had the mechanical tk22 carbs, not the vacuum operated tk26.

shamal wrote: ok. after :
-a good carb reconditioning (oring on the mix screws-fuel level- float needles with better springs etc)
-changed 12v wire for the left coil, that where pinched
-new d8ea

i filled the carburetors with gasoline. no overflow problems, all ok, and she started and finallly IDLE on 4 cylinders, just a little bit rough, but she idle at 1200 rpm. after a bit of warm up she doesnt' refuse the throttle. it's running.
.the only'' problem'' i can see its a certain difficult to reach very high rpm only when i open wide suddenly the throttle. (she a little bogging) maybe, or maybe not, because of the old hardened diaphragms (but at all with no cracks)
cylinders temperature after a pair of minutes: 170-180-165-170 c°
all this WITHOUT being synched. later i will do a sync, and i think she can improve.

i think we can rule:
1- the ''sticky valve'' problem.
2- the ic igniter trouble , since i swapped it (with another i know it's working), and she run in the same way.
3. the pick up rotor 180° off (or she won't start at all, i think)
4- a general ignition system trouble.

i think my poor abused carburetors are now at the best they can do. i want to buy a spare carburetors rack.

tips? opinions?

If the rubber's in the carbs are hard, it won't run for SHT.. Rather than buying carbs and dealing with them, maybe you should try this.
Steve
jbmindustries.com/

Thank you, i dont understand well what kind of service is this. Can you explain better? Thank you

He makes rubber parts. You can order some from him for much less than other places using your slides.
Steve

i did a diaphragms swap some year ago. on the tk you have to cut the plastic on the top and then use glue. not the best think to do, it worked and still work..

you think hardened diaphragms can be a real problem when the engine is hot? i noticed that when the engine is warmed up, the heat tranfer to them also, and make them softer

They have to be elastic to work properly. They meter the air if hard, the bike will starve. I like his system. Wish they were around when I had my CL 350 in the 70's. $100 a piece and I was making $3.25 hr in 73.
Steve

Synched. Now the sync screw respond well
This is the best i can do with those carbs

.edit