fishgod

My Feedback: (13)

The Plane Sig Cap 231ex
Engine Saito 180
24 oz Sulivan Fuel Tank
Power Master 30% Heli Fuel.
Large Fuel Tubing

Originally I had a Great Planes 24 oz. tank on the CG and I was using a Perry pump. Was having problems with the plane dead sticking after a huge loop or a long downline. I thought hmmm maybe it is my tank plumbing so I replaced all of it. Still had the problem. I Then I thougth hmmmm must be the pump and tank placement. I then used a new Sulivan 24 oz. tank and moved it to the stock location and removed the pump. Flew it yesterday and out of 5 flights I had 3 dead sticks. Bring the plane in after a dead stick and see that the fuel line has huge air bubbles. Checked tank and It was 3/4 full. Thing is driving me crazy. I have never had these problems with a 2 stroke. Could the enging be sucking up all the fuel in the fuel line while it is in a down line? Doesnt seem likely. but hey who know. Any help would be appreciated

Michael

ajcoholic

My Feedback: (10)

Is your clunk flexible enough to fall into the fuel on the down line? Maybe its too stiff - replace with a more flexible piece of tubing or shorten it.

AJC

fishgod

My Feedback: (13)

I have always been taught that you do not want the pickup line going to the front of the tank. Am I wrong here?

Michael

SKYBLAZER1

Hmmm, I'm thinking...did we wrap foam rubber around the fuel tank? Maybe that's it. That 1.80 is real shaker! Are we maybe foaming the fuel?

fishgod

My Feedback: (13)

Tank is wrapped in foam. I am going to try a trick I heard about. They say if you put a couple drops of armoral (sp?) in a gallon of fuel and it will stop the fuel from bubbling. Hey anything to get this thing going. Although I am getting quit proficient on my dead stick landings.

bpu699

My Feedback: (1)

I always make sure the clunk reaches the front....

SloFlight-RCU

My Feedback: (2)

If your downlines are long enough to make the engine die....you're FLYING TOO HIGH!!!!

fishgod

My Feedback: (13)

SloFlight
Is there such a thing as flying to high.

Matt Kirsch

My Feedback: (21)

The clunk is supposed to stay in the back of the tank. I've personally never heard of it being done intentionally any other way. How would you keep the line from kinking and/or getting stuck in the front? The line would have to be so short that you could only get to half the fuel in the tank.

In most cases, Newton's Laws of Physics hold true, and keep the bulk of the fuel pressed against the back of the tank. Unless you're somehow hovering nose-down, the acceleration from going into the dive will press fuel to the rear of the tank, and since both the airplane and fuel are accelerating at the same rate due to gravity, enough fuel tends to stay there to keep the engine running.

fishgod

My Feedback: (13)

mkirsch,
With that remaining true. I probably have some fuel foaming and that is where it is getting its air in the fuel line.

rctimm99

My Feedback: (34)

I had the exact problem....

It was bubles in the lines but my system was airtight.

1. Use large, not ex large tubing
2. The bubles where coming from the engine getting HOT and fuming the gas at idle.... is this engine getting hot? Is over proped... My fix was to lower nitro to 5%, but on a 180 4 stroke, I would not do this.... I would look at prop, cowl, heat of engine...
I bet you are getting hot.


Just a thought.
Tim

fishgod

My Feedback: (13)

rctimm99,
It was about 48 degrees out Sunday and I'm running the engine pretty rich. 9600 peak, turned down to 9200 for flying. I am currently using a bolly 17x8. Engine doesnt seem to be to warm at all. Lots of oil on the bottom of the plane. Thanks for the Ideas keep em comming

SloFlight-RCU

My Feedback: (2)

Move out of alaska!! , j/k.. I grew up in palmer and moved to colorado in 1997 after spending a year at UAA...sure is pretty (cold) this time of year!!!!

fishgod

My Feedback: (13)

SloFlight,
I came up here in 91 and fell in love with the area. Then to really mess things up I met my wife up here in 92. Well you know the rest of the story

ajcoholic

My Feedback: (10)

I didnt mean to let the clunk line not reach into the back, and also it wont fall all the way into the front - BUT I have seen quite a few fellows have the clunk line made from too stiff of fuel tube that has little or no flexability. Thats what I meant to check. Also, in a large tank (>24 0unce) the clunk will fall forward a bit, since the tank is so wide and deep and if the clunk is set up with enough flex and not hung up at the back, it will move ahead.

About the fuel sitting "in the rear" of the tank, if you are braking on a down line, you are definitely NOT accelerating, and more exactly you are not accelerating anywhere near 9.8m/s/s so the fuel will indeed fall towards the front of the tank. Newtons laws DO hold true, the fuel in the tank is not able to be held at the back unless you are in a loop and centrifical force is holding it there. Rarely in a vertical dive you are accelrating anywhere near the acceleration due to gravity.

AJC

Cyclic Hardover

My Feedback: (3)

I kive in Anchorage in 78 79 80. Are any of your fuel lines making a 90degree turn? Maybe coming out of the firewall to the engine.? It may not look crimped but it can be and cause problems. This happened to me and I sent the engine bac twice in a month. I just made the line longer and problem solved.

Joe B.

My Feedback: (1)

The whole intent of the clunk is to move where the feul is. If you didn't need the clunk to move to the top, left, right and (close to) the front then it would have a stationary pickup. What happens in high-G type manuvers is your clunk gets thrown around with the feul and keeps the feul coming. As far as armoral, I use it and it works great. Take a gallon of feul, shake it up. Once the bubbles settle add 3 or so drops of armorall. Now shake it. No more bubbles!

- Joe

rcrickc

I have had a similar problem with 180 in Hanger 9 CAP with a 24oz. tank. Their is not enough pressure from the pressure tap in the stock muffler to pressurize the system sufficently. Noticed especially when I would pull a sharp 90 degree (1/4 loop ) up line from horizontal at about 1/2 throttle and then go to full throttle. Engine would some times die or at least "stumble" badly. The fix was to install a Cline regulator and move the muffler pressure tap into the exhaust elbow between the cylinder and the muffler.

bigphil

My Feedback: (6)

Use of Armorall in your fuel will cut down on foaming but it isn't recommended. You are adding silicone to the fuel which will deposit on the internal engine components. Plug life will be shortened and eventually a glass-like coating will be found on the inside of your engine. It's much better to properly isolate the tank from engine vibration rather than adding these kinds of things to your fuel.

BalsaBum

Fishgod, try a fuel filter in the line near the carb. This mod solved
the same problem on my saito equipted stick. It will also keep crud out of the jets!
BalsaBum

fishgod

My Feedback: (13)

Well if the weather holds I will be giving it a try tommorow. Everyone cross thier fingers.

rcflier_gi

My Feedback: (2)

Silicone and Silica (glass) are not the same. The Silicone in Armorall will not form a glass like deposit. A couple drops in a gallon is all that is needed and with not cause any harm or build-up in the engine.

deadstick

My Feedback: (1)

The muffler pressure tap on the 180 is notorious for loosening, and eventually stripping out. I had this happen to the one on my Cap, resulting in a deadstick. You might want to double check that the pressure fitting is tight. Good luck.

Tom