Posted Monday, October 19, 2009 @ 11:02 AM  

Looks like I'm joining the ranks at last.

It is N1771, serial 4057 based in Arizona.

It has a bit of fuselage covering cracking that I will need to recover eventually, but for now I plan to enjoy flying it for a while before undertaking a recover job.

It has a Rectimo engine with bigger cylinders making it 1400cc.

It has an AeroCarb with mixture control, no float, along with a fuel pump with the fuel return circuit so as not to over pressure the carb

It has an electric starter, with Mag and alternator.

I bought it from Sam Korth, but was owned by about 5 others before that including Phil Paul.

It seems to have lived most of its life in the South Western US except for a stay in Alaska in the early years.

Interestingly, Mira Slovak also asked Sam if he could buy it as he had a plan to fly it over to France for the 2010 Fournier Gathering, but must have reconsidered that and never followed up on it.

Its wings are covered with the Hipec system and has a nice glossy finish still.

Sam Korth is a really nice guy and keeps himself busy, now that he is retired, flying B-17's and other WWII craft around. He also has a few Hangers with projects in them. He is probably busier now then when he was working.

Once again I'd like to thank Collin for his tip on Sam's RF4D that made this all possible for me.

Ray

[Edit by jb92563 on Monday, October 19, 2009 @ 11:16 AM]

Posted Monday, October 19, 2009 @ 03:20 PM  

His buddy at the Cafe while having lunch was joking around with him about not having flown it yet.

I plan on keeping the RF4D hangered at French Valley Airport.

I will be ferrying it from the Phoenix area next weekend if that Hurricane down by the Mexican West coast dies gracefully without sending any moisture up my way.

Posted Monday, October 19, 2009 @ 08:40 PM  

On your first leg besure to verify your fuel burn.

Posted Friday, October 23, 2009 @ 04:38 PM  

I just found out that the carb is acting up and my ferry flight is going to be delayed another week while the problems
get sorted out.

It seems that the carb adjustment is not quite right yet as the engine started cutting out after a short 15 min flight.

My gut feeling is that perhaps its not the carb at all as he said that it ran beautifully right up to the point where the engine started sputtering.

Perhaps an air leak in the fuel or induction system that manifests itself as the temps get higher.

I suppose it could also be the Mag.

I feel relieved that this was caught and will be rectified before I take it on a 350 mile trip over Mountains and Desert.

I'll post the findings here when I find out more.

Posted Saturday, October 24, 2009 @ 01:49 PM  

Make sure the vent hole in the fuel cap is pointing forward. Also if the spark plug gap is too big it can also cause a misfire.

Posted Wednesday, October 28, 2009 @ 10:52 AM  

Looks like my delay in picking up N1771 was due to vapor lock of the Aerocarb.

It will get additional heat protection for the carb body, fuel lines and Gascolator to see if that rectifies the problem.

In reading about the Aerocarb I also read something interesting in the installation recommendations and from users posts on various forums.

The Aerocarb should be installed with the slide oriented vertically.

The reason for has to do with the location where the fuel comes into the carb from the jet.

Apparently it favors one side if installed with the slide operating horizontally, which causes the stream of fuel
to favor the cylinders on that sides intake port, ultimately resulting in that side being extra ritch and the other side being leaner.

(At low to mid range the fuel does not atomize that well and rather runs through the intake as more of a fuel stream)

Overall it makes for a somewhat poor mid to idle range that is difficult to tune properly with the Aerocarb.

Also I read that in the dual port intake for the VW, there is commonly a divider in the intake pipe between the two ports and that it also causes
uneven mixture between the two cylinders in the idle to mid range due to that fuel stream following the shortest distance and entering the closest port.

Apparently it can be ground out making a small plenum area between the two ports and results in more even mixture in the two cylinders due to the extra turbulence.

Dan, take note of this in your install and try to avoid these gotchas.

This is all very interesting and makes me wonder if anyone has come up with some vanes for installation in the intake tubes directly after the carb to cause a swirl and get more uniform fuel/air mixtures to occur so all cylinders get a uniform mixture?

Posted Thursday, October 29, 2009 @ 08:36 AM  

Although I mostly fly aerobatics and would appreciate an inverted fuel supply, I would not touch an Aerocarb or any of the other similar slide-operated things.

Too many of my friends have had problems, including numerous engine failures immediately after take-off due to vapor-locking. The most recent guy broke his back in the ensuing forced-landing on the remaining runway ahead and will never fly or walk (or have sex, which is much more important) again.
He's 33.

These things need a constant, pressurised supply of cold fuel. Even two pumps (one mechanical and one electric) cannot guarantee that, and then you can't be sure the fuel is cold.

Also it's important that the ambient pressure and temperature and fuel head stay constant for the mixture to stay constant. The mixture changes when you have a low fuel tank, high or low air temperatures, high or low altimeter settings, high altitude airports and whether or not there's a Z in the month.

Another buddy who used and recommended his Aerocarb sometimes used to trail black smoke on the climb-out; other times his engine sputtered and backfired due to weak mixture. He had a couple of off-field landings. He's dead now.

The original Zenith 29RXZ carburetor is simple, reliable, light, compact and well known. I trust it. So should you. They still come up on E-Bay.

I am going to try Sam's uncle's Mikuni carb on my Australian Fournier, but I shall be very careful.
I have also recently been told by my Austrian VW expert that he's found a Zenith 30RXZ, which would be better suited to the bigger bore motors (1400cc) and I might try that too.

I say again, after over 45 years in GA, and 21,000 flying hours on around 250 types, I don't trust slide carburetors.

Good luck.

Posted Thursday, October 29, 2009 @ 10:53 AM  

Relaiability and safety is the most important thing and I have not seen that consistantly from Aerocarb.

I'm hoping to bring N1771 home this Saturday and these carb problems have made me a bit nervous about it.

I'll be flying high on my way back 8K-10K feet so I can get a 15-20 mile glide should the engine quit.

Posted Thursday, October 29, 2009 @ 02:54 PM  

Not sure if the old carb will work with the new bigger cylinder cc's but it had crossed my mind to put it back on if the
Aerocarb proves to be a problem.

I understand that drilling out the jet slightly on the Zenith has been working successfully.

[Edit by jb92563 on Thursday, October 29, 2009 @ 02:56 PM]

Posted Monday, November 2, 2009 @ 12:17 PM  

It flys fantastic, I am extremely pleased and enjoyed a sunset flight by the end of saturday after I finally discovered the way to start it.

The RF4D made the 325 mile trip with only 1 hiccup along the way.

I got down to Coolidge, AZ with Sam Korth (previous owner) and spent all of Saturday trying to teach me how to start
the thing, and us scratching our heads wondering why it is so hard to start.

We seem to have black sooty plugs all the time, although I'm going to pull the plugs before I run again to see what they look like after a 325 mile trip at 3200 rpm.

We tweaked the Aerocarb needle every which way we could think of, clean the plugs 2 or 3 times and gaped them to .019".

Seems like although sooty, they were sparking well.

By the end of the first day I finally figured that there is only one way the engine will start for me with this aerocarb.

1) 1/2 throttle, mixture full rich, then open the fuel valve and start immediately.

2) If it does not sputter or start within 5 props, then close fuel valve, full lean, and full throttle after waiting a few minutes to clear the rich mixture out.

Then start at step 1 again.

This thing floods extremely easily.

I think the hard starting is due to the fuel coming out by the needle on one side of the carb and the split in the intake being right after the carb most of the mixture enters one bank of cylinders only.

It was impossible to hand prop as I dont think it was possible to get enough airflow to suck fuel into all the cylinders.

I think I will need to orient the slide vertically so the fuel is equally divided into each bank of cylinders.

This carb also slobbers fuel quite a bit so it important to only open the fuel valve when the engine is running, and probably floods the carb with fuel if you turn it on too soon when starting.

I dont know if my install is typical for this carb but its going to need work to make starting easier.

An Ellison sounds like a better idea since it atomizes better which I think is most of the problem for mine.

On my trip I cruised at 3200 rpm which gave me 105 mph in calm air. Running up to 3600 only added a few more miles per hour.

I feel like perhaps my prop could use a bit more pitch.

The engine did act up at one point for about 3 seconds where is seemed to be suffering from improper mixture.

My guess is that either some bubbles or dirt or water effected the carb momentarily so I immediately went full ritch mixture, turned on the fuel pump and opened to full throttle.

After that it ran normally as before and I put everything back to the way it was and continued cruising.

I cant imagine it was ice as its typically pretty dry near Palm Springs and was not that cold at 7,500' MSL.

During the flight I leaned the engine till it sputtered occasionally and then ritched it slightly and was getting 3.2 gph

That makes the tank good for 3 hours cruise plus a little reserve.

The engine oil temp never went much past 90 C and was just over 80 most of the time so cooling was fine.

I have a few things I'd like to adjust to my own preferences like, more battery capacity along with thicker wires to the starter from the battery, as 12 guage wire was used and I think 10 or 8 Gauge would be better.

Also my original french compass is completely obscured and needs to be restored or replaced.

Anyone able to restore theirs?

[Edit by jb92563 on Monday, November 2, 2009 @ 12:39 PM]

Posted Tuesday, November 3, 2009 @ 01:48 AM  

Great you have your new bird home.

Does it have a fuel pump or gravity feed?