22mm keihin carb
The choke could be in need of resetting, the floats could be off specs, your carb probably needs rebuilt or replaced.
if you got a carb rebuild kit most of them have the tolerances in them. if not there are maunals on that motor on eBay for that year motor
what are the carb settings fro a 1988 f350 pickup
NGK DR8ES-L gapped at 0.6 - 0.7 mm
I saw repair manuals on e bay, or the dealer or service professional should have that info.
Assuming that it has had a full tune up including points and condenser and the dwell and timing have been set to specs and the vacuum advance is working properly, the rebuilt carb may be at fault.
The available engines that year were a 200 cubic inch 6 cylinder, a 289 cubic inch 8 cylinder, and a 302 cubic inch 8 cylinder. Assuming you meant a 289, your best bet would probably be to purchase a carb kit, rebuild the carb, and follow the instructions for adjustment. That should give you a baseline to work with.
That is the correct carb Mikuni VM30SS ID # 44560 All the parts and specs are listed in the service manual you can get digitally on ebay (p. 105). I am looking for a rebuild kit, but it seems one would have to find bits and pieces here and there. I am awaiting to talk to the owner of vintage iron to see whether or not their 30mm plug and play carb is compatible. Goodluck to you sir or madame! ...Also see this... http://www.advrider.com/forums/showthread.php?t=647090
Need more info - cam specs - intake type - compression ratio - valve size - headers? - type of fuel
Go to Mikuni Corp.'s website and there is a pdf file that gives the dimensions of their carbs so you just have to measure the one that you have and compare it to the specs on the chart and to find out which one you have. Hope this helps :)
either your float level is set too high or there is gunk between the float needle & seat inside the carb. open em up, set the float level to the proper specs. pull the needle & seat and clean & polish them. if the needle & seat are too far gone, order new ones and replace.
wow