misses

[chuck]

Hello, I have a xs1100lh, the tank has been creamed, the carbs have been off 3 times by my self, cleaned, checked for everything the book said to look for, took it to a yamaha dealer, lost $500 there, went to another place they did better, but it still did the same thing, took it apart again found dirt in carbs, but I didn't think it should hurt the way it runs. Took the coil to another place, they said it checked ok, took off the carbs again and they have been there for 2 weeks with no word back yet. The bike has new plugs, new wires,checked top end, looks good, added extra fuel filters, set the carbs with a mercury gage, what it does is misses terrible, all 4 cylinders, it will run good for about a 100 feet then start acting up, right after fixing it, all the plugs are fouled, burning rich, need help.

chuck

[cabinover]

Check your petcocks. Sounds like the diaphragms are shot. On Suzuki GS's, if the diaphragm is done, it will suck raw gas through the vacuum line to the petcock right into #2 cylinder. How is your air filter? Try pulling the element out and see if this helps. Something is either feeding way too much gas or stopping airflow.
Check pilot jet sizes and mains too. If I remember correctly, mains stock 137.5, pilots 45.