Alright gentlemen,

I'm getting a little frustrated w/this carb (thats almost new btw).

I was setting mixture screws for highest vaccum, and I noticed that the front driver side screw needs to be all the way in for the engine to run good. The others are around 3/4 to 1 turn out. Whats up w/that? I was setting the screws w/the vaccum advance disconnected (so I could use that port for my guage). Should advance be hooked up for this?

Next question and most important - do the secondaries need to be opened? They are now and the engine idles w/the idle screw all backed out. My guage is reading at least 15"+ of vaccum - and it will probably go higher once dialed in.

Thanks again.

Vacuum adv. should be disconnected. Try opening the throttle blades by adjusting the idle up sligtly. Screw is all the way in beacause the engine doesn't
need the fuel if it doesn't have air. Make sure the timing is set before you set carb. And you may need to go back and adjust the screws more than once...........good luck

Might help if we knew what carb you have.

its not a demon or berry grant is it? if it is.... good luck, i'm still foolin w/mine

Sorry,

Its a 750 DP. Front jets are 70's and the rear are 82's w/blocked PV.

Make sure your idle air bleeds are all open. Something blocking the passage will cause that corner to be way rich, maybe that's why your engine doesn't like that screw out. Metal shavings from machine work when the carb was built can sometimes still be lodged in these passages. You should have the screws out at equal amounts if everything is alright. The vacume advance should be connected and the aircleaner should also be installed, I usually adjust for the highest rpm then also check with a vacume guage. With a good low speed tachometer slight changes are much more noticeable than with a vacume guage, especially if the engine has a cam with a lot of overlap. Highest rpm usually goes hand in hand with best vacume reading. Tis better to be a little on the lean side and keep the plugs nice and clean than rich at idle. JMO Bob