Bit on the lean side, not sure what Demons come with out of the box, 31 squirter is fine, order gaskets for the bowl and metering plate, order a power valve plug, order a pair each of # 74-75-76 jets. Ok, that said be very sure that the accelerator arm has zero lash to the pump and cam and it squirt...

First off, is the accelerator pump adjusted correctly, is there fuel coming out of squirters, have there been any plug color checks to see what the mixture is? What pistons are in it, (compression ratio) ignition timing?

I put a 74" NGQ on Barefoot Betty, "Betty Osceola's" AV 540, Fenner hull #1, pushes great and quiet, I put a 74" Whirlwind Whispertip on Zilla, #4 Fenner hull with a 10:1-220/520 AV much more impressed with it's performance vs the Q.

Well, I can say that I have witnessed what harmonics can do, 3 blade sensenich on an O-540 cracked the crankshaft lengthwise through the sealing area of the shaft, through to the slinger and thrust flange, continental O-520, 3 blade again, sheared off every timing gear bolt, neither of the engines h...

The airtec starter doesn't require a separate solenoid, run start button direct to the starter activation lead.

You have to take in consideration of clearances, bearings, ring lands, wrist pin to rod and pin bore in piston, now the other thing to consider is, your camshaft is preloaded by valve springs, which will allow it to rotate easy one way, feeling the lash in the gears is likely what it is.

That is too short, but if you can get it for the right price, locate a set of longer blades to put in the hub.

Cut damaged tips equal length, set pitch to desired rpm, wouldn't suggest under 68" diameter.

Here ya go.

Drain oil, fuel pull all plugs, will need to have starter and alternator and all wiring replaced, magnetos will need rebuild, ok now, fill sump with fresh oil, doubtful that starter will work, but try it, need to spin it over and get oil pressure with plugs out, drain out carb, flush with fuel, you ...

Aircraft spruce has them, will try to remember to post part number when I get home.

Ok, I searched this thread for a reason, get this,,, a Jurnigan built Parallel valve O-540, spinning a,,,,, ready for this? 70" Sensenich 5 blade at an average of 7.5° as the pitch is all over the place, varying from 8 to 7° only 2700 RPM, I told the kid that either his engine is real tired or the p...

One coil, 2 plugs to fire, 1 plug fires say cylinder 1 on compression stroke, and other fires cylinder 2 on exhaust stroke, coil packs and driver determine which amount of cylinders to fire and sequence, tone ring on flywheel determines TDC and RPM to run the sequence to driver.

C25 works, tri mix gives a blonde weld and cleaner appearance.

Plumb to center of hull, and prop shaft plumb to leveled hull fore and aft.

-8 fittings or at least 1/2"NPT to adapt to.

As per the pm, the mellings number superceded, this will work, or find a exact replacement for the 1978 chevy 267 V8 https://www.ebay.com/p/2154369144?iid=253073614920&chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=253073614920&targetid=935431404853&device=m&mktype=pla&googleloc=90...

Here you go.

Valve seat is not ground correctly, the seating area is too far out to the outer edge of the valve face, the seating area should be central to the valve face, I will try to find a picture to illustrate it for you, the edge of the valve on the seat, with likely bad contact full circle of seat caused ...

If it has the zenith carb on it still I would suggest a Holley 500, and a modified intake to mount it on, where are you located? I can fab up a manifold for you.

I reference the bottom for size, it does not run on the top, you can measure a manufacturer's hull at the bottom that they claim to be 8' x whatever length, and the bottom measures 6'8"wide.

Glad you got it squared away, the withdrawal was terrible, haha!

If you have access to a press brake with v block lower and round upper dies that is 14' long I can walk you through a design that will perform flawlessly.

Use the bellhousing flange bolt hole, cut the unused tab off the starter bracket to use the other bellhousing hole, bolt a piece of angle to that and build from there.

Yes, and a very lean condition.