Engine out...carb ice

[gyro]

Well so much for the myth (at least what I've been told) that a pre-mix 2-stroke wont ice up. I had been up for about 45 min and was heading back home when the engine started loosing power. I tried full throttle and it got worse I pulled it back and it seem to get better for a secound and then it went almost to idle. I picked a nice big setaside field and made an easy landing....is there any other way to land a quicksilver MX :) I looked back at the engine after landing and all seemed normal but the Carb had tons of water beading off it...hence the assumption it was CI

Anyway pulled it out of the field and used a guys paved driveway to get back in the air and B-lined it for home before it did it again.

The humidity wad 83% with a DA of 2600....lesson learned.

[Timchick]

Glad it was uneventful.

[GrantR]

Here is a chart and it does say it happens to all engines.

http://www.kfackler.com/gtuf/carb_ice.html

What was the temp and dewpoint?

[gyro]

It was 83* when I was flyn....and when called the airport auto weather that evening (aprox 2hrs later) they had a DP of 22c

thanks for the link

[CLS447]

Nice job ! I love the Quicksilver.

Now .......what can we do about it ?

[phantom]

I don't know how the myth got started about no ice on two stroke unless they were thinking about the early rotax that some of us had with a tillison carb that flange mounted to the cylinder and the carb temp of over 100 degrees prevented ice, not the oil in the fuel. The mac is almost ice proof for the same reason as the early rotax.

[GrantR]

You were in the green area of the chart so you had the risk of serious icing at cruise power and icing at glide and cruise power.

[edypaul]

Its no myth that slide carbs are very resistant to icing. Carburetors with a throttle plate are a different story. I would look for another cause just to be safe? Another member of this forum thought he had carb ice. When he looked inside the jugs the cyl was scoured.

[phantom]

with a butterfly type carb the mixture always goes rich , low egt. with a slide valve carb it can go either way, I have had them lean out to the point where if not shut down it will burn up, it depends on throttle setting and how bad the conditions are for the ridge of ice to form inside the mixing tube.