I would like to know if anyone here has tried the Road Demon 525 on a street Y block with mild cam? 

It says that you can use it for cams up to 220 @ .050.  I have an E-4 so should work?  I like that the road demon has the 4 corner idle, & the adjustable air bleed, & also the quick access secondary diaphram cover.  The Jigantic fuel bowls don't really serve any purpose for me, but they sure are shiny!

I would like to order it soon, so I can put it on this weekend.

Also, do the demon's have a pvc port at the front of the carb??  I don't want to go backwards on the pvc since i use the eddy for that currently.

Does the Road Demon JR have an adjustable air bleed??  I never saw where it did..

What did you fellas do as far as Jetting goes??

I like to get an idea of what someone else's baseline was compared to bolt on....

I've got the Road Demon Jr. on my 312 and the primary idle only - suits me fine. Bowls are smaller  - but they don't dwarf the engine either.

I did use my 1" spacer, & had to move the coil to the firewall to also clear the fuel inlet. 

Kid - you mentioned you used # 68 jets?  Mine came with 58's, & a 6.5 powervalve.  the thing is way rich & was chugging initially just to stay running so I swapped the power valve for a new 7.5.    The four corner idle is proving to be just as kid mentioned a pain initially.  I ended up closing the secondary's nearly all the way, & it really functions more like a 3 corner idle since the pcv port is in the rear, & points at the secondary bore on the passenger side.   That screw wants about 2 1/2 turns, & the other on the secondary side wants 1/2 turn... go figure since my secondary side of the spacer has 1/2 of the divider removed & nicely radiused.(I mimicked the stock 2 barrel spacer on the secondary side only)

It is still rich, i pinched my rubber fuel line to the carb with vise grips to help drain the carb for the power valve change, & about half way down the bowl as far as float level is where the vacuum came up & the idle became crisp.

I think i am going to drop 2 sizes on the primary jets, & run it to see what the plugs do. 

I think i need to work with the timing curve a little.  I am running about 24 at about 900 to 950 rpm idle, &  total timing of 38 with about 5 or 6 degrees of that being in the vac. pot.

My RDJr is jetted up to 61’s in the primary side.  And mine also came with 58’s originally.  The upping of the jet sizes cost me a ~½ mile to the gallon in overall fuel economy but cruises much nicer and runs harder when I put my foot into the throttle.  Spark plug readings are perfect at this point.  The stock #65 power valve is in place.  If I wanted to mess with it further, I would drill out the PCVR channels in the metering block out a little larger and try the 58 jets again.

A #75 power valve will open sooner than a #65 power valve.  Opening positions are 7½”Hg and 6½”Hg respectively.  A #65 power valve will take more throttle opening or a reduced amount of engine vacuum to open it as opposed to what’s required for the #75 powervalve.

I need to play with the timing more, but I only pull about 10 in. of vac at idle. 

In theory the 6.5 power valve should be better...

In the spirit of only changing one thing at a time I jetted up to 64's.(need to get a read on the plugs)

Runs much better. 

Having most of the idle issues due to the secondary idle & the initial amount that the secondary's are propped open by the set screw.  I always made sure my secondary's were tight as a drum on my 4100's years ago... The 4 corner Idle calls for seeing a small amount of the transfer slot when viewing from below the plates... I have closed it 98%, will most likely close it the rest next tune session.

Need to change back to the 65 power valve, since I still only pull 10 inches of vac.

I may also open up the valve lash on the e-4 from .015 to .017 to help the vac, & idle quality & tunability.

I

The adjustment they suggest for the front idle transfer slot (adjust blade closed till the remaining opening looks square when viewed from under the carb) worked OK on the primary. Then I adjusted the stop screw for the rear throttle plate to keep the engine running - so I didn't have to alter the primary position. Used the front bowl level to set the total mixture up and down - centered the rear in the glass. The Demon is way more responsive to this move (or at least it seems to be) than any of the Holley's I've tuned.

The newest carb I got - the Road Demon Jr. - had a sticky needle and seat that drove me crazy  - until I changed them both to steel. Everything would seem to be working OK - and without warning - garbage mixture.

But it still sounds like a vacuum leak on your end.  Depending upon the carb spacer you’re using, carb gaskets are suspect either from a poor match to the spacer or just not sealing due to irregularities in the surface.  The ‘B’ manifold is already sensitive to carb spacer issues if the carb flange has not been milled flat.  Double check that the intake bolts are still tight also.  Just running lean on the back cylinders makes the intake manifold gasket suspect or a vacuum leak associated with the rear manifold vacuum port.

I pulled the  possessed demon.  After talking to tech support they agreed that the application was correct & that there could be something wrong with the carb.  Said to send it in.

I mean while pulled the thing apart to get jets back to factory & noted a few key issues:

1: The passenger rear main jet had filings packed in behind it.(explains the idle screw settings on the secondary)

2: the secondary throttle bores don't even come close to closing when you back the idle stop screw all the way out...(I can understand the obvious intentional mismatch in the machining of the bores & blades to keep a small amount of air here, but common!

I plan on trying it one more time before sending it back. 

I have cured the idle quality issues with valve lash using the eddlebrock to regain a baseline.  Opened them up from .015 to .017.  Man what a difference.  Best idle vac directly before setting the lash was 11.  Directly after with same idle speed reset is now 13.5.  Idle speed now is @ 875-900 in Neutral, & about 750 in gear.

Hope to drill & tap my allum. spacer for a front pcv port first before attempting the Demon again.

If the Demon dosent work this time It looks like I will be pursuing a vacuum secondary adaptation of some sort for the eddlebrock, as this is my primary complaint with it.