MV99

My Feedback: (4)

Hi Troy,

Thanks again for your advice a month ago on my YS 160DZ; so, I dropped from 19x8W (top RPM @ a little over 8K) to 18x8W (top a little bellow 9k). Since then, the 160DZ has been happy running until 2 weeks ago (after 75 flights) one of the head bolt came completely loosened.

I did not reliazed it and flew 4-5 times with the head bolt off and I think the head gasket is damaged so I could not seal the gap anymore. I am going to send the 160DZ to YS parts & services to fix the issue.

I then decided to put my new YS 170DZ in my Cap-X. I did order APC 18.1x10W but couldn''t wait for it to arrive so ===>

** I broke in the YS 170DZ with 18x8W using CP 30% heli and ran 5 tanks of fuel with the first two tanks bellow 4.5k RPM.
** I made about 5-6 flights with 18x8W (HS setting @ about 2.25 turn). I did lean it for a very short period of time and, man, it hit over 9.6k RPM.
** I then switched to 19x8W and was not sure if this creates too much load for the engine. It seemed to turn out ok because I am setting HS @ 1 and 3/4 turn and top end RPM is about 8460 (I once reached almost 8.7k and back out a little now) and idle very stablely at 1650.

I have put about 30-40 flights now with 170DZ now. I do feel the weight of 19x8W prop quite a bit heavier than 18x8W and I hope to have your opinion that if 19x8W is little too much load for YS 170DZ?

I do feel better mid low end torque and also overall power is stronger on 170DZ, at the same time, it does shake quite a bit more because I use the same Hyde soft mount (HCMY16RISA). At the idle, I can see clearly it rotates much more than 160DZ. I don''t see a Hyde mount that dedicates for 170DZ so I hope the current mount will sustain the extra horse power.

Many thanks in advance!!

Mitch

Troy Newman

The top end rpm you ahve is fine...you will probably like a prop that sppols up better than the 19-8W....This is a flying preference. If you are around 8000 or a little above the 170DZ will be very happy. I would not like to see it running up over 9000...but you can fix that by just not opening the carb all the way..

The Hydemounts are basically the same for the 140-160-170 engines. Merle will change the rubber loading a bit but its not that critical.

Troy Newman

MV99

My Feedback: (4)

Hi Troy,

Thanks a lot for the advice. I will restrict the opening on carb a bit and try the 18x8W to compare the difference in spooling up with 19x8W.

Mitch