3DHS 91" Yak 55

[crfabbro1]

Like all engines be patient with the break-in. My EME 70 is in an 91"EF Yak and after a couple gallons it start very easily in cold weather. What is your all up weight without fuel? My EF Yak is 19.4lbs. and it has all the power you want.

 

[ryan_m]

I haven't weighed mine yet, need to do that. Do you have any baffling on your Yak? Mine dead sticked on me today, first flight out. I got it down with no airframe damage, but did snap a leg of the landing gear. I was too high to make the runway and stuck it into a slip, and wound up getting off track of the runway and landing in the mucky ground/weeds to the side of the runway. I could just feel heat oozing out of the cowl as I carried it back. Stuck an IR temp gun on it, and the front of the cylinder was 185 degrees, I'm sure the back was well over 250. In the air right before the dead stick it wasn't going above about half throttle. I cycled up and back to mid a few times, and then went down to 1/4 throttle, and then it died. I think it was overheated then. Ambient air temps today were about 60-65. Yesterday was 40 and the three flights I got were fine. Today I had this problem 5 minutes into the first flight. So I think I need to do some baffling on that big round cowl and get the cooling air over the cylinder heads.

Just not sure how best to do that!

 

[crfabbro1]

I have no baffling on mine, and never had a heat issue. I ran a Falcon 24-9 from
the start. Be sure to keep the engine on the rich side. A little rough sounding early in the break-in but smoothed out after more flights.

 

[ryan_m]

Hmm, same prop I'm running. Getting about 6600 rpm out of it right now. Guess I'll pull the plugs and see if they look lean or not. I had to open the low speed needle a full 1/2 turn to get it to start the first time, so I sorta figured it would be rich. Transition was a smooth, though a little sluggish compared to the dle-55's and da-60's I've had, so I figured I was rich from that too. Perhaps not. Will pull the plugs tonight and check.

 

[ryan_m]

Buddy of mine made a composite picture from one of the flights of my Yak on saturday. Came out pretty cool!

 

[toysforbigboys]

@ryan_m that is awesome that you got to Maiden your bird...I am still in a holden pattern, just to dam cold for me here in MI

 

[ryan_m]

Got 9 more flights on the Yak this weekend. Have about a gallon of gas through the EME 70 now, and she is finally breaking in and getting easier to start. First 10 flights or so on it were a chore to get the motor running. Flip until it pops, choke off, flip a few times and it fires very briefly, and then you have to re-choke and repeat. After about 5 cycles it would finally stay running. Now though, it's like a normal engine and starting well. I do flip on the choke until it pops and then about 3 more flips after the pop. Then un-choke, and she fires right up. Or at least it did on today's three flights. Very happy with the EME so far. Much smoother than the DA60 and EME60 that I've had. Spinning a falcon 24x9 to about 6700 rpm now.
The Yak is a great plane too. I'm running the small SFG's on the wingtips, and can fit the wings into my wing bag without taking them off, so that is very nice. Not as rock free in a harrier as say the 3dhs 87" Extra, or 89" Slick, but not bad at all. With the larger SFG's it probably would be perfectly stable in a harrier. Does incredible crankshafts though. Very very fun on that plane. Really nice knife edge death-slides too. And speaking of knife edge, it's perfect, even with no mixes. First plane I've ever had that was that way. Snaps are also a thing of beauty on it. Very precise and quick snaps. Loving the plane! Now I just need to get a few days to fly without having 15 mph of wind to contend with...

 

[toysforbigboys]

Got 9 more flights on the Yak this weekend. Have about a gallon of gas through the EME 70 now, and she is finally breaking in and getting easier to start. First 10 flights or so on it were a chore to get the motor running. Flip until it pops, choke off, flip a few times and it fires very briefly, and then you have to re-choke and repeat. After about 5 cycles it would finally stay running. Now though, it's like a normal engine and starting well. I do flip on the choke until it pops and then about 3 more flips after the pop. Then un-choke, and she fires right up. Or at least it did on today's three flights. Very happy with the EME so far. Much smoother than the DA60 and EME60 that I've had. Spinning a falcon 24x9 to about 6700 rpm now.
The Yak is a great plane too. I'm running the small SFG's on the wingtips, and can fit the wings into my wing bag without taking them off, so that is very nice. Not as rock free in a harrier as say the 3dhs 87" Extra, or 89" Slick, but not bad at all. With the larger SFG's it probably would be perfectly stable in a harrier. Does incredible crankshafts though. Very very fun on that plane. Really nice knife edge death-slides too. And speaking of knife edge, it's perfect, even with no mixes. First plane I've ever had that was that way. Snaps are also a thing of beauty on it. Very precise and quick snaps. Loving the plane! Now I just need to get a few days to fly without having 15 mph of wind to contend with...

Well you are a lucky ....I still have not been able to fly mine....I am hoping in about 6 weeks the weather will break and I will be able to maiden...

 

[49dimes]

Got 9 more flights on the Yak this weekend. Have about a gallon of gas through the EME 70 now, and she is finally breaking in and getting easier to start. First 10 flights or so on it were a chore to get the motor running. Flip until it pops, choke off, flip a few times and it fires very briefly, and then you have to re-choke and repeat. After about 5 cycles it would finally stay running. Now though, it's like a normal engine and starting well. I do flip on the choke until it pops and then about 3 more flips after the pop. Then un-choke, and she fires right up. Or at least it did on today's three flights. Very happy with the EME so far. Much smoother than the DA60 and EME60 that I've had. Spinning a falcon 24x9 to about 6700 rpm now.
The Yak is a great plane too. I'm running the small SFG's on the wingtips, and can fit the wings into my wing bag without taking them off, so that is very nice. Not as rock free in a harrier as say the 3dhs 87" Extra, or 89" Slick, but not bad at all. With the larger SFG's it probably would be perfectly stable in a harrier. Does incredible crankshafts though. Very very fun on that plane. Really nice knife edge death-slides too. And speaking of knife edge, it's perfect, even with no mixes. First plane I've ever had that was that way. Snaps are also a thing of beauty on it. Very precise and quick snaps. Loving the plane! Now I just need to get a few days to fly without having 15 mph of wind to contend with...

My mind is made. I getting one! Now send me some MONEY!! lol

 

[49dimes]

Well you are a lucky ....I still have not been able to fly mine....I am hoping in about 6 weeks the weather will break and I will be able to maiden...

You guys not getting any of this unseasonal warm weather??