100cc fuel tank size??

[Steve]

What's a good size fuel tank for a BME 105? I'm using a 32oz and I have a lot of fuel left over. Will a 24oz tank be large enough for 15 minutes of flying 3D style??

[dmcquinn]

I run a 24 ounce tank for my DA 100 and set the timer for 14 minutes. I fly a combination of 3d and general sport flying. I land with a few ounces left.

[Steve]

Thanks.

[BobbyRichardson]

WOW I have a 32 oz and I only get 15 to 17 minutes.

[dmcquinn]

I'm in the minority. Most 100 cc gassers are supplied by 32 ounce tanks. I start my timer just as soon as the engine starts. The engine normally warms up for one minute before take-off. Very little fuel is consumed at idle. So I really get only 13 minutes of flight time.

Most of the guys with 32 ounce tanks will land with more in reserve. I view this as just carrying extra weight.

[crazyjoe]

10 minute flight 32 oz half tank left da 100

[Steve]

I'll give the 24 oz tank a shot and see what kind of milage I'm getting.

[dmcquinn]

Steve - make sure you use a timer. I find my results very consistent. I must use the throttle about the same every flight, because the tank ends up about the same (a few ounces left) every time. And make sure your clunk is performing properly. When you're down to the last few ounces, the clunk becomes more important.

[airbike]

If you find that 24 oz just doesn't leave enough reserve for your comfort level, add a 4 oz header tank.

I've been running a 24 oz main tank with a 4 oz header tank for a while now and it works great. The header tank is almost always full so much less chance of sucking in air.

[Cracky]

A suggestion to be on the safe side (the weight of fuel is the most important weight you want to know about when in a hover) is to set your timer for 15 minutes and fly long lines, tall uplines, using a lot of throttle. Then check the remaining fuel in your plane when you land. This way it will show you what is basically the maximum amount of fuel you would burn in a 15 minute flight of any style of flying.

[Steve]

Thanks for the advise. The header tank sound like a good idea. I'll set my timer for 10 minutes for the first few flights and see what I'm getting. Since this will be in a new plane, the first few flights will be pattern type flights. Once I get it trimmed and adjusted, I'll be doing a lot of 3D, (what I'm capable of anyway).

Doing a lot of uplines on the first few flights will help me get it trimmed!

[krayzc]

Dgflick,

I find this is the best way to find out your needs also. Then you'll know that if you are doing the low and slow stuff that you'll have many oz left to play longer if you are flying that way on the tank.

[Hinckley Bill]

Hey airbike....

Any chance of you posting a pic or two of your header tank setup, as I'd like to look at this as an option?

Thx,

Bill

[airbike]

Sorry Bill, don't have any pics.

I just strapped the 4 oz tank next to the front of the main tank. Carb line goes to clunk of header tank, vent line of header tank goes to clunk line of main tank, main tank vent as usual.