No top end

[johnny rezny]

Hey fellas Haven't been on for a wile Been working on the 715 Thought I had a Handel on this no top end issue but "NOT" Was thinking I wasn't getting Any speed do to not enough vacuum to pull the vacuum advance forward on my civy distributor when I'm at top throttle. put a Mallory one in that uses a macanical advance and is electronic still the same problem. A little better but not what I would like I would like to get up to a round 50 to 60 miles an hour 40 is about my best.Checked all the usual suspects.Timeing, wires, fuel pump its beginning to get me down anyone had this problem befor? Im thinking It mite be the power valve in that holly two barrel mite not be opening up gonna call around to a few carb shops and pick a few brains as what im doing here thanks from Mich Johnny

[glenn]

How long has your carb been sitting. This new gas likes to wreak havoc with old carbs. Holleys and power valves are known to not get along so I would check that. Are you sure you getting enough fuel volume to the carb, not just pressure. Plugged filter, pickup or fuel pump getting weak. Randyscycle on here is pretty good with carbs too.

[johnny rezny]

sat for the winter but this been going on for a year or so .Got it narrowed down to that power valve . Back fired a bunch I mean a lot!! though that carb I guess that's really a bad thing when it comes to these holly carb's gon'a take a vacume reading in the morn and tear it a part again and put in a new power vavle the right one and go from there !!!!!!!!! Read a lot a bout it on the net helpd a great deal