FLYMIKE

Nope, the conversation went on for along time. I was confused on his suggestion so kept asking. I asked how does the clunk go to the other side and he said use a heavier clunk (heavy duty dubro) still have it, and said use fuel line that more flexible. I ask him "wouldnt the line if bent back like that "Kink" off the fuel and the reply was get the dubro tank with the tonge and groove in it. And the tonge was fore the clunk to rest and slide into so the line wont kink.

It seems I was getting alot of bad advice back then. Even from the owner of the local hobby shop to the point to where i gave up this hobby until now. RCU and you guys are awesome.

Keep up the good work

Maudib

My Feedback: (51)

Hmmm and I always thought the front tip on the DuBro tanks was so you couldn't jam the tank so close to the firewall and kink the lines coming OUT of the tank...

Oh well... you'll still find misinformation on RCU too... just try and get a few opinions and go with the "consensus"

FLYMIKE

Yah that makes sence but so did his reason of keeping the clunk in the fuel whether your plane is going virtical or on a downline. I didnt use it because the clunk is huge, and very heavy. I did set it up and the clunk moved freely without kinking the line but opted not to use it.

STG

My Feedback: (26)

OK, I see my fatal flaw, I was thinking the tank remained full of fluid without any air gaps.

On a full tank there is very little if any gas that will leak out of a sealed tank. As soon as there becomes an air volume in the tank it will bleed until the pressure is equalized. The more air in the tank the more it will bleed before it stops—My hands smell like gas.

FLYMIKE

Maudib, on my Yak, what would be the drawbacks of using the shortist standoffs on my EVO45 so I can get the hole carb into the firewall. The static hole on the carb doesnt have a hookup for tubing and when the air pressure changes in the cowl it will effect the performance of the engine. So I heard. If I enclose it in the firewall (carb is on the back) then just shorten the cowl to fit and get cg on track, what kind of flight performace do you think I will loose?

Maudib

My Feedback: (51)

ROTFL

Maudib

My Feedback: (51)

I would not worry about it... it's important to build as the manufacturer suggests as it was designed that way... and it all comes together...

The rear carb engines seem less plagied by the air pressure issue than side carb engines...

Doesn't your carb have a port? The manual for the 45/58 shows a 58 carb and it has a port on it already????

and even if it doesn't and you did have an issue (I'll bet you don't) you can always remove the plate, drill a hole and solder your own port onto it and run a line into the fuse...

Maudib

My Feedback: (51)

Also be sure to THOROUGHLY read the section on starting and the way the ignition operates... that new igntion does some kind of "dry firing" to clear the plug when it's first turned on...

IF you happen to be at just the right rotation point (somewhere near top dead center) it could cause it to fire or even start... plus they have a series of steps to follow for easy starting (I guess( I don;t really know as I haven't run one myself... just passing on what I heard for you to look into...

STG

My Feedback: (26)

With the B46, I am using a 3-line system with filter in the clunk because it is the simplest connection from the clunk to the carb. RC Showcase recommends this, and if I remember correctly, claims that more gas related running problems happen because of an air leak than any other cause.

It appears to me that the more rigid Tygon type tubing used for gas may be prone to small air leakages of a fuel dot over time? No big deal on a fill line, but could cause some erratic running in a "T"ed in gas line. I know, countless people run "T"'s in gas systems without any problems.
_______
I have run a check valve on the vent line of OS160 and perry pump with good results. The complication is that you need to remove the valve when filling the tank. I have also used no check valve and not noticed any fuel leaks out the vent line.
_______
I also run a 3 line uniflow system on my inverted Saito 100 with VP30. I set it up uniflow (fill and vent thru a 2nd clunk—also fill vent that I plug when not filling) from the beginning because the carb is much lower than the fuel tank and it works great.

Bob Pastorello

My Feedback: (198)

:-0

FLYMIKE

My carb is a walbro but is totaly different then that picture and in my manuel too.
It has two ports- one for fuel and the other from engine back plate to the carb. The picture you show has a plate with the rubber seal coming out the sides, and a port, but mine just has a small hole and its not in the center of that plate its near the edge of the plate close to the head.

The choke plate also has a hole in it , and Im thinking that it would cause a problem trying to draw fuel to the carb when priming. Wierd

Maudib

My Feedback: (51)

Mike...

The carbs might differ a bit from batch to batch as availability might keep them switching from time to time...

Anyhow... it's a pretty easy process to add a static port should you need one...


STG... You are right... the Tygon does start to get loose on the dot... it's advisable if a person uses the 2 line system to occasionally snip 1/2" off the fill line to have "fresh tightness" to Dot into...

I really like them both... but the 3 line system has the advantage...

RJConnet

Dave, (Maudib)

Where did you get that right angle nipple that shows in the pix on your post #1302, I could sure use a couple of those to get rid of some big loops in my fuel tubing which don't hurt anything but look terrible............. RJ

STG

My Feedback: (26)

The Hayes BLACK NEOPRENE gas line is very flexible. I am using it on the clunk of my short 10oz gas tank. I also plan to use it as my fill line as it looks like it will work well with a dot. http://www2.towerhobbies.com/cgi-bin...&I=LXK824&P=ML

FLYMIKE

How does it compare to tygon, I mean would you use it for full line settup?

Maudib

My Feedback: (51)

RJ,

I didn't get it... (tee hee) it's fromt he manual of the Evolution 45/58... don't know who sells them... I'm scared to do a google search for right angle nipple...

Mike... the black neoprene has been around for omse time and is used for fuel line systems... nto really sure why people moved to Tygon... It's nice to be able to see the fuel in the line move (when nothing else is on) .

FLYMIKE

RJConnet

As you read the following, imagine the sound of a funeral dirge in the background.

Some days at the flying are good, some are not so good and some are really bad, yesterday was one the latter for me. I arrived early at the field with my brand new EF 74" Yak powered by a B46. First step was the engine off range check, over 40 yards. Next step engine running range check, same as the first. Let the plane set for a while and got in a flight with my OMP Yak profile to sharpen the thumbs and get the knees under control. Started the B46 and it was running great, taxied out and gave it about half throttle. The Yak gathered speed quickly and was soon airborne, Lifted off and into a climbing turn to the right. At about 100' altitude
experienced a total loss of control, plane rolled over and dove into the ground engine still running about half throttle. Total loss, guess I can't say total because the engine survived with only a little dirt and some grass stuck in the cylinder fins, The elevators are still useable as is the rudder.

I haven't a clue as to what caused the failure, The receiver just came out of an Edge 540 with many troublefree flights on it. The transmitter was the same one I warmed up earlier in the day and used again later in the day. There was nobody at the field that was even close to my frequency. I had run the engine on the plane for about half and hour tied down the previous day with all controls working perfectly. About the only thing to do now is to start saving my pennys for anothe Yak....... Pix below....[] RJ

P.S. The second picture, somebody at the field caught this picture as the plane went into the death dive.

STG

My Feedback: (26)

RJConnet, very sorry for your loss. [:@]

Maudib

My Feedback: (51)

RJ...

Totally, toally sorry for your loss there... I recall the pics from the "Combo" thread and the cowl cutout work was really sweet... you really put some effort into it...

I recall you using dual 1500 nimh and switches right?

Did you just lose all control like there was no power to the receiver? Was the battery tray still intact?

Were the batteries only velcroed to the battery plate?

What I'm getting at isthe battery tray looks like it's only glued across the balsa stringers (amd may have not made very good contact with the center one)

It's possible the batteries wobbled enough with the vivration to break the tray loose... on a climb they fell back into the tail, if you used nothing to tie the battery leads to the switch ports or sued just masking tape like the elevators,,, the weight could have just unplugged themselves from the switch... at the crash scene it would have looked like they were "ejected" at impact...


I've seen ply to balsa joints fail pretty easy, especially with 5 minute epoxy... it doesn have time to penetrate the balsa and only gives a very light surface bind... the surface "fuss" of balsa peels away easily adn it's a wek bond for sure...

Just trying to help find an answers to help figure this one out for you and prevent something int he future...

You also mentioned the 1500 nimh batteries only charging to 1350... can't imagin both failed at once though...

EXTRA ADDICT

My Feedback: (2)

That sucks sorry to hear you lost it. You did a beautiful job building it. I hope you get another one soon!

xtraflyr

My Feedback: (11)

If the Batteries did come disconnected. I learned to use those yellow clips for the connectors on all my connections, batteries and servos including the ailerons everytime I plug them in.. Whatever happened it totally sucks.. You almost never really find out. Unless somehow you got interference fron the ignition somehow.. Maybe EF will hook you up somehow. Tell them about your problem and maybe theyll give you a discount or something..

Cya,
Frank

EXTREME FLIGHT

RJ, that is sickening! I'm very sorry to see that. Scott at Brillelli and I were just talking the other day about how nice of a job you did on your Yak especially the cowl cut-outs.
Contact me at 770-887-1794 or email at [email protected] and we'll get somethiing worked out to get you a new Yak. Again, Im sorry for your loss.

STG

My Feedback: (26)

I had a chance to do an initial balance and all up weight on the E.F 74/B46 combo today. I am only missing two items--Fromeco Badger Failsafe Switch and Smart-Fly Optical.

I can adjust CG from 6.25 to 6.75 depending on where I put the gas tank and 4oz receiver battery. What are you guys running for CG? I tend to like a bit more forward CG than most as I don't like to give up any precision in the plane, but still like to 3D in the same flight. I am thinking that 6.375 might be a good starting point for me? I know manual states 6 to 6.75. On my plane 6 inches is about center of wing tube and 6.5 inches is back side of wing tube.

Looks like my all up weight without the switches and mounting for receiver and battery is about 11 pounds 14oz (no spinner or wheel pants and Xoer 20x8 prop) This is better that I was shooting for. This should put me just over 12.5pounds on take off with full tank of gas.

I used a Rapila fishing scale that proved to read wrong for the first time in three years. I have standards at 2.5,5& 10 pounds so I am able to calibrate my scale in 2.5 pound increments and today my scale read heavy. At 5 pounds the scale read +1.5oz, 7.5pounds +3oz, 10 pounds +5oz, 12.5pounds +6oz, 15 pounds +7oz, 17.5 pounds +9oz. The scale actually read 12 pounds 4oz when I weighed the plane, but I corrected by 6oz due to my standards--this is the first time the scale was off more than 1oz with these same standards?[&:]

xtraflyr

My Feedback: (11)

Sounds like its goin to be awesome!! I'm running my CG at 6 5/8" and its fine for me. I like to hold little bit of up when inverted. Mine is at 11lbs without glow fuel. Flys light as hell!!

Looks like the crappy weather is moving out finally. I need more flights, I only got a teaser of 3 flights,and need more!!!

Cya..