Holley/Demon Carb stumble
OT, I know...... but just continuing on the Demon QC theme......
I bought a King Demon 1090 when they first came out.
I was running a customers 540BBC on the dyno, dialing in a few carbs.
I had a 1050 and a 1150 Holley to try, along with his new 1250.
I figured I’d make a couple pulls with the new 1090 to see how it stacked up.
The Holleys were all on the rich side at WOT, and pretty fat at part throttle, but all idled fine and the motor exhibited no “weirdness” with any of them.
Bolt the 1090 on...... idle speed just wanders all over the place, and isn’t very responsive to mixture screw adjustments.
Made sure float levels were good...... attempted a pull.
Motor doesn’t take the load very well...... start the pull, it’s kinda surging, check the a/f...... waaaaay lean, abort run....... put it back in the box.
When I had a chance to look at it I found a few manufacturing defects.
The first was than one of the booster stake tubes had the booster end folded over and crushed...... so no fuel is going through that one.... hence the super lean at wot.
I looked for that right away when I got it apart........ because I had actually run into that on two previous BG built 4500’s.
The next issue was, one of the metering blocks must have moved when it was being machined because the hole at the top of one of the main wells was all oblonged.
There was a big gap on one side where the idle tube was pressed in....... and then someone filled the gap with clear epoxy.
The real problem there is, the epoxy ran down into the void and plugged up the idle tube.
I called and talked to the rep...... they said just send it back and they’ll take care of it.
I said no thanks, just send me two disassembled metering blocks and a set of booster stake tubes, and I’ll take care of it myself...... which I did.