Originally Posted by Adv Grifter
Could be the diaphragm but I'd bet on the Pilot Jet. With your experience you should have no prob pulling the carb off and giving it a good clean.
Sometimes grit hangs up in the small Pilot Jet passages, has to be 100% clean to run well.
Parts in the BST Carbs do wear out over time. Slide, Jet Needle. Also maybe pull the needle jet in the float bowl, check for debris and make sure rubber tip is firm and sharp.
Sometimes its cheaper to buy a nice used, low time BST Carb and just put that on. Good luck, hope you get her up and running!
MCMA? I used to be a member in the early 90's. I hear the property is looking good with new trails. Great group of guys!!
If it has the stock petcock, try setting it on prime to rule out a problem with the vacuum petcock.
Dirtly: 2009 Suzuki DR650SE Road Sofa: 2001 Yamaha (ad)Venture 1300
Dirtlier: 1999 Suzuki DR350SE Old Sport: 1979 Suzuki GS1000E
1996 Suzuki Intruder 1400 (for sale) 1987 Yamaha TT600 (for sale)