Carb: Proform 950 DP (Holley knockoff) I'm in the process of disassembling and inspecting the subject carb to resolve a poor running engine problem. I don't know if the carb is the main problem, but I'm checking it out along with the entire fuel and air system, valve train, ignition, etc. This carb tear down and inspection is unfamiliar territory for me, so please forgive me for the simplistic questions. So, here goes: 1 - How can I tell if the power valve is damaged by backfires? NOTE: The carb is only equipped with a primary side power valve. 2 - After removing the float bowls, I find that the metering blocks will not separate from the main body. I even tried prying them apart with the thin, flat blade of a paint scraper. They won't budge (although I didn't pry too hard for fear of causing damage). Should I just go ahead and buy new gaskets and try prying a little harder? Or are there some additional fasteners to remove (can't see any)? 3 - When I position the throttle linkage in the full open position, should all for throttle blades be exactly perpendicular to the lower surface of the carb base? That's it! See, I told you they would be simple questions. Thanks for your help, you guys.
To test a power valve, you have to apply vacuum to it and see if it remains closed. http://www.chevyhiperformance.com/techarticles/74058_carburetor_valve_problems/ I'd try to spray the gaskets to try and soften them up. If you have removed all 4 bolts, the bowl should separate from the main body. Yes, the blades should be perpendicular to the base.
Thank you, Larry. Removing the bowl was easy enough. It's just the metering block that seems to be glued on.
OK, Larry I got it off with very little damage to the blue gasket (wrinkled both side edges). I salvaged the gasket, but I'll eventually replace it. The power valve appears to be OK according to my precision vacuum check tool (my mouth!!!). Thanks, Larry.
old school method for checking the power valve.....:Brow: the best thing to do is to just replace it fairly often , say every 2 years.... holleys made after a certain date already have a anti-backfire valve installed... and I forget the date.....o No: a old trick for preventing gasket stick is to coat the gasket with grease at assembly....Vaseline works good.... the main thing that messes carbs up is foreign material /and corrosion from water in the system... the other thing is failure to install a heat shield under the base plate,,, allowing exhaust gasses to corrode the plate.... this will happen very quickly because the gasses have a weak solution of sulfuric acid in them....and,,, some fool doing like I did a year or 2 ago , breaking the ''ears'' off the base plate.... i have only done that once in my entire life.....[thought I had all the nuts off the studs] WRONG,,,, TALK ABOUT FEEL STUPID.....:Brow: the big secrete to making holleys or any carb, for that matter, run really good , is to when you get it all together, do all the adjustments correctly.... adjust right to the factory specs.....then you know the basics are right, and you can go from there , writing down , in a book, all the changes you make, so you dont get confused or duplicate mods......:Brow:
