I believe the Cosmos fuel was from the Japanese team and it was shipped late to Muncie. They gave it away to other flyers at the end of the week.. It was 10% oil content. I ran some of it with the OS-200 supercharged FI motors and mixed with Coolpower to get an acceptable oil content. Seemed to run well.

Ron Barr

I have a question about excess oil( seems to be mostly raw fuel) on the plane. Engine runs well but it seems to be coming out of the check valve on top but I have replaced it and still a problem. My current 1.75 is now doing it as well. Any ideas?

Hi Mike
Check your pump diaphram/gasket and the o-rings on the pump and head. Next , Then resurface the valve cover on a glass plate with 800 wet sand paper, to make sure it`s perfectly flat.
Depending on the engine version , the pump adjustment housing and the faceplate on the pump valve housing will have irregularities causing the diaphram to either get cut over time and leak, or the o-rings are not seated good in the head

Also inspect the hattari O-ring , make sure it`s an original Hattari. All others I`ve tried are not sized correctly and leak under pressure.
This is most likely the problem if both motors are doing it.

These are the most common leak problems.

Bryan

Thanks Bryan, will do. also how do you feel the 1.85 compares to the 1.75 maintenance and reliability wise.

Mike, I don`t have enough time on the 185 to make that comparison yet
But I think the good points so far are:

1The removal of the Pulse tube to the pump ( this gave fits to some with clearence issues and cut tubing causing lean up line runs)
2The fuel economy is better resulting in much cleaner runs when set correctly.
3The sound (tone is deeper and sweeter sounding under load)
4The bottom end Torque is improved ,and we can run up to 1" bigger diameter props reducing rpm and noise further.
5The weight is nearly the same
6Vibration is less
7The power jump is equal to the jump from the 160 to the 170 with the hyper pistons.
8 overall tuning is easier to set.
9 less smoke than the 175 ( all plays into fuel economy,and cleaner runs)

Although I must say the 175 has been the best 4 Stroke ever produced by YS as far as trouble free and maintenance SO far, I Think the 185 will be equal to that standard.and this motor is another Grand Slam!
Bryan

that sounds great. will go from there

Hallo can any one tell . What is the last wire on the new ignition box is fore? Cant see in the manual ...

RPM telemetry.

Hallo super du you no how it work i have mz18..

No.

Test flown the 185 this morning, first flight with a 20.5 x 10 PN, about 7,000 on the ground with slightly rich setting. Changed to a 20 x 10.5 PN from the second flight on to put in more flight & break in time before switching back to the bigger prop. First impression, very effortless for up line & good, slow down line. After about a 9 minute flight on P-15 & a few F maneuvers, it still has slightly less than half a tank of fuel left on a 600cc tank. Since the whole morning was pretty calm, it will be interesting to see how much fuel it'll consume on a windy day. Will fly again tomorrow for more evaluation.

Adrianhttp://www.rcuniverse.com/forum/atta...mentid=1983573http://www.rcuniverse.com/forum/atta...mentid=1983574

Adrian, I've been using the same prop on the OS GT33 gas engine. I get practically the same numbers as you indicate with the 33 also brand new.

It's a terrific prop except for its weight. 175 grams is a bunch. I made a wood carbon hybrid which weighs about 77 grams and similar in size.... 20 1/4"x12". I narrowed the blades 1/16" compared to the APC and thinned them compared to the APC, but otherwise the planform of the blades is identical to the APC. Paid very close attention to the trailing edge of the new prop, making is as sharp as the APC. The results are outstanding. Picked up rpm and the thrust from the 12 pitch is noticeable.

If you want to tackle the project, lets talk in private

Adrian,

Where did you get the model stand if I may ask? where in Japan if itis from there?

regards

Alejandro P.

It's from K&S Japan, I don't think they make them any more.

Adrian

Nishioka has one that is similar.

Guys

I spent the last few days tweaking my 185 and adjusting the needles.
I`m so impressed with this motor. The flight times are so good I can fly two p or f patterns and land with 2 ounces of fuel left in the tank, an 18.Oz tank. this is the Non CDI Version! it will get better once this thing breaks in and I can lean it some.

Running a 20.5-10 APC the power on the bottom is so good and smooth. the tone is sweeter and vibration reduced throught the whole throttle range. I had so much flight time on a gallon, I almost forgot to charge my on board pack ( kinda ruined my routine ) it confused me a little trying to figure out how I flew all day on a gallon. I lost track of how many patterns I flew. I had to go to a negative throttle curve to get the same power feel from the 175.
I love this motor more every time I run it.

It`s a Home run!

Bryan

Hey Bryan,

Just imagine how much better it would be with a 10 or 12oz tank... Fuel is heavy!

Cheers,
Jason.

Hi Jason


With the fuel on the cg you cannot tell any difference from full to empty !
I used to run a 12 oz tank in one of my valiants with the cdi and felt I was cheating myself, although the E guys loved it :)
Having the ability to fly back to back patterns in practice one P one F same conditions is a luxury and time savings you have to experience to appreciate !
With a 20oz tank ,I might get three patterns on a calm day Hummmm,,

Bryan

From personal experience, not everyone is thrilled with our ability to fly 20 minutes on a tank of gas. Then again, my situation could be unique....

Hi Matt,

I was only speaking from a power to weight ratio. If one considers that 20oz of fuel weighs approximately 600 grams halving that amount does affect the vertical performance. It certainly did in my old Pinnacle with a 140RX. I did a lot of work lightening this model and it made significant difference at the top of a vertical. The YS would probably not suffer here but I can only presume that performance would benefit. Like towing a trailer behind the car.

A 20 minute flight is probably too much for me. Personally, I like to have a flight (8 min) and then review it in preparation for the next flight. It also gives other members a fair go at the flight line. ;-) Everyone to their own though so if it works for you and you have the field to yourself then do it.

Cheers,
Jason.

We have been flying for years two complete sequences on a single tank of 500 and 600cc, it is so good when after one sequence you can simply start all over again trying to improve the previous.

The 185 is without a doubt the best YS yet, and nothing compares in power and torque to this one yet, and we will see the real animal when the new prop from APC is out, wich should be any moment now.

I too am waiting for the185 prop. I'm getting 7400 rpm with the 185cdi.
If the new prop pulls that back to around 7100 it will be much better. Make more use of the huge amount of torque these engines have.
When someone knows they are released, maybe they can post here.

I struggled to make weight with my Valiants. Switching from the 18oz tank to an 11oz tank saved 15 grams. If I can get more weight out, i may put the18 back.
I plan my practise when there is no one at the field, so flight time isn't a issue for me.

Well, you can always fly gas, as I do. A 240 ml tank will fly about 12-13 minutes or about 1 1/2 sequences. And gas is much less dense than glow so the weight gain is about 6 ounces. An 8 oz tank in the middle of the cavernous fuses looks a little silly. I admit, but it works normally as one expects.

The OS GT33 piped 2 stroke gassie puts out similar power to the YS175; a little better top end for the same props but slightly lesser brakes at idle. Very similar mid range tork. The YS185 based on Bryan's and Adrian's reports is at a different, higher level. I'm all for that....but not about to change my gassies....

Let me suggest that you make your own from an XOAR or Falcon ELECTRIC woody. Shape it like an APC, thin the blades down and sharpen the TE. Then cover it with 3K carbon cloth and epoxy, and bag it. This is a proven working concept that I have used on many props. It sounds like the engine should turn something like a 22x10 or 22 x 12. And BTW, any APC of this size will weigh about 200 grams. The woody-carbon hybrid weighs about 85-90 grams. Juuust a little weight savings.

One of the better props I've made for my GT33 is a 20 1/4 x 12. The engine loves that prop and it is very similar to an APC blade shape. APC's are the best in design.