I have a DA-100 with about three and a half gallons of gas thru her. The engine is in a Hangar 9 35% Extra 260 and performs really good except for this wierd richening when I roll. I can do huge loops and Cuban 8's were I am inverted for a long time and there is no change in RPM or how the plane runs. The only time the engine seems like it will die out is when I am flying straight and I do a roll. This also happens in either side knife edge and at no other time. The engine idles awsome and transitions are perfect. I have not changed any of the needle settings because the thing runs too good. I have checked the tank and it is ok and also tried to cut a bigger exit hole in the cowl but nothing seems to change this. I think the performance otherwise is great; uplines seem endless. I have only had 50cc planes in the past and have never experienced this issue. Any help you guys could offer would be greatly appreciated. Thanks.

Tom

Is this the new 100 ?

I maidened the plane in November of last year and do not know when the new version was released. I bought the engine in about a month prior to the maiden. How do you know if it is the new version?


Tom

Check the cliunk line, this line can get stiff and not move to the fuel. Have had this happen to me and I now check quite offten. May not be your problem but a place to start.

Originally Posted by 1080tommy

I maidened the plane in November of last year and do not know when the new version was released. I bought the engine in about a month prior to the maiden. How do you know if it is the new version?


Tom

Ok no its not the newest one then--the newer ones have a red plastic reed housing.

Lean out your low end needle a little.

Tony fandino

lean that low end a screw driver blade at a time then fly and re-tune until its gone.....

Originally Posted by 1080tommy

I maidened the plane in November of last year and do not know when the new version was released. I bought the engine in about a month prior to the maiden. How do you know if it is the new version?


Tom

yours is not a new one. the new one is lighter, and it only became available recently.

Thanks for the ideas. I am going to see what DA says and then go back to the basics; check the tank, and lean the low end a little. I hope I get it because the thing flies great.

Tom

I hope this helps someone with the same problem but I talked to the guys at DA and they said that sometimes the air blowing over the hole in carb plate will cause this problem. They suggested a carbon fiber carb plate cover made by Troy Built Models which I will be purchasing, but they said for now just use a square made from thin aluminum. I used a popcan and it completely fixed the problem. I immediately noticed that slow rolls had no change in engine pitch. I then did some knife edges that I could not do before and what a difference. My friend who is a better pilot then me by a mile took it at altitude and did some rolling harriers and inverted stuff and it ran perfectly in all orientations. Now that this is fixed this motor runs flawlessly and I have just gotten four gallons thru it this season so I will be switching to synthetic oil on the next flights. Thanks for all your advice I am glad to have a place like this to aske questions as I am newer to gas engines.

Tom