So you mentioned a QQ Yak engine over heating. If you were hovering around yourself for a couple of minutes it is not supprising that the engine quit. If it was breaking in you surely did damage and hurt it because it needs to cool, the air from the prop does not cool it that much. Even if the engine was broken in it would still get hotter than the surface of the sun if you hovered for several minutes.

Originally Posted by Stainless Skills

So you mentioned a QQ Yak engine over heating. If you were hovering around yourself for a couple of minutes it is not supprising that the engine quit. If it was breaking in you surely did damage and hurt it because it needs to cool, the air from the prop does not cool it that much. Even if the engine was broken in it would still get hotter than the surface of the sun if you hovered for several minutes.

SURFACE OF THE SUN Wow thats dang hot? Ive had a couple Da 50cc.Never seen one that hot dude! A little pink around the edges maybe? Had
One in a EF 88" YAK. Exactly the same troubles. Sounded like a bag of nails in the harrier and would fade on power during the uplines. It would also loose power all of a sudden in a sustained hover. I was thinking maybe it could be the dreaded blow back the manual speaks of if the run in isnt done correctly? However i tuned the engine for maximum smoothness and responce to throttle inputs. Flew it with the cowl off to make sure the power wasnt sagging. Then put the cowl back on and have had no troubles since. The nasty mettalic warrble sounds vanished and the power is awsome now. ALL due to a different air temp i reckon in the cowl. The same engine in a 28% extra was running sweet as with no power loss or strange noises but slap it in the Yak and the cowl makes a wayyy different atmosphere for the engine to opperate? Dont give up on your Da mate. Tune it to suit your yak. What oil content are you using? Seems there a bit of a debate on what's the best percentage? With glow engines oil helps cooling but with petrol excessive oil makes the engine run hotter with loads of carbon deposites? Im sure with a bit of a tweek your engine will be sweet as a nut Sustained hovering with ample cooling is not a problem. Ive taken off with my 28% extra streight into a hover an held it onder 15ft for 10 mins in the prophang on a 24/8 with no overheating or power loss.

Well I've cut the entire front cowel intake out on the 72" Yak and cut out all the louvres and made a few more cooling exit holes. I realise it was my own fault that caused this accident with my beloved yak.

Got an electric lined up for it though And for my Matrix

Originally Posted by ampEater

Well I've cut the entire front cowel intake out on the 72" Yak and cut out all the louvres and made a few more cooling exit holes. I realise it was my own fault that caused this accident with my beloved yak.

Got an electric lined up for it though And for my Matrix

Sounds like youve given up on the ol' DA? GOTTA BE GASSERS ALL THE WAY

Oh the motor was an OS 1.40RX btw lol Should've mentioned that.

When my new job settles down and I get around to getting a Comp ARF 2.6 Extra I'll be going for the DA so don't ya worry

Originally Posted by ampEater

Oh the motor was an OS 1.40RX btw lol Should've mentioned that.

When my new job settles down and I get around to getting a Comp ARF 2.6 Extra I'll be going for the DA so don't ya worry

Fairplay.. Duh me so slow. Thought ya was huckin the 85" qq yak.. Had a power sagg with my saito 220 last sat during a long hover with my sebart funtana-140. Alas was only the muffler vibrating loose n had to kinda harrier land it a bit quick from the vertical. Thankfully no damage tho

Yeah that's what I've figured with I.C motors, as long as you run one you will always encounter motor sags for whatever reason, usually when you least need them. Hence Why I am going electric for my Yak. That, with the added reliability of my new DX-7 should help eliminate or at least reduce any risk of equipment faliure.

Now the only thing left to eliminate is the old "Dumb Thumb" syndrome hmmm....... me need a sim