Popping & puffing at a study low speed

[rainman]

When I am running along at  low speed such as in the city or out in the country say at 35 to 45 and holding a study throttle the old gal pops and puffs. Sound like one carb on each side.  If you twist the throttle just a hair it quits then it will catch up and start popping and puffing again. At highway speeds it is just fine 50 and up. I have checked for vacuum leaks using car cleaner and found nothing, checked spark plugs and they were ok. The only thing that I have not done is to check the synceizlion of the cabs. (do not have any gages) is the reason why. The bike has not been DE smoked. The bike runs great and the mileage seems to be the same as my I/S.  Have I over looked something. Any ideals     
Thanks
rainman #284814

[Buda]

Mine was doing that sort of thing (prob worse that yours) with a couple of clogged slow jets...maybe run some Techron thru and see if it gets better.

[rainman]

will try it first thing in the morning. 
Thanks

[Momz]

Check the vacuum hoses on the middle intakes on both the right and left sides.
I'd bet they are cracked/collapsed and in need of replacement (ASAP).

[john]

   " bike has not been DE smoked "            
                                    pull the trigger !            
 " The bike runs great and the mileage seems to be the same as my I/S. "         

[rainman]

well I have narrowed it down to cyclender 1 & 2 that is doing all the ropping & puffing did put a can of techron in the tank it was for a 12 gallons between yestarday and today I have put around 80 miles and no change not even a little bit    ???.

[Old Geezer Richard]

 Hey rainman , I have experienced with my Old Fat Lady that when it comes to carbs & their performance , pouring chemicals in the gas tank DON'T always cure the problem or problems  ... do your homework and snoop around , like the obvious vacume lines , vacume port caps , clamps , down tubes  , o-rings and your exhaust header nuts and exhaust seals .... I myself use gumout high mileage about 3 or 4 times a year and my baby is running good but not great .. I feel its time to tear down and clean up the carbs ... Thanks the Geezer

[FryeVRCCDS0067]

Might be worth draining the carb bowls, they might have accumulated some condensation over the winter. I drain mine every spring.

If your petcock diaphragm is leaking gas back down the vac line it might cause that problem on one carb, but not two. My son's valk is sitting in the garage right now with that problem waiting on me to heal up or him to have time to fix it.