gra95770

I have just purchased a used 140 DZ and have had no experience at all with YS. On trying to fire this engine up I found it to be a bit difficult. It tried to start on several occasions but stopped almost immediately.I found that if I took out the glow and blew off excess fuel would try to start but stop again,whilst this was going on fuel was dripping from the exhaust,any ides anyone.

Troy Newman

Chances are the engine was flooded.

The DZ motors no longer use the pressure regulator system. As a result if you put a "T" in the tank pickup line to fill the tank it can pump fuel through the engines pump and flood it. This can make the engine spit a little drip a bunch and not start.

The key on that is to somehow pitch the fuel line to the pump on the engine side of the "T" fitting this will keep the fuel from pushing into and past the pump on the engine. I run my fuel lines outside the model. Close the line to the tank with a plug when filled. Then I connect the line to a fuel filter than leads to the pump on the engine right before I start it. This eliminates the issue.


All of the YS engines with the Pressure system don't have this issue...only the DZ or Dingo motors. The same problem would occur with an OS 46 if you filled it the same way.

Another option to cause the flooding is filling the tank and then sitting the model in the sun. The tank will heat up and expand a little causing fuel to siphon into the engine flood it. So I keep the like pinched or disconnected until its time to start.

Troy Newman
Team YS Performance

gra95770

Troy,thanks for your support,it may be my problem because I did notice when I filled the tank there was a heap of pressure in the tank,so much that fuel squirted about a meter out of the fuel pump infeed line,yet when I took off the line from the fuel pump to the carburetta and spun the prop by hand very little fuel came out

Troy Newman

On the DZ engines there should be no pressure in the tank at all. Perhaps there is a check valve in the vent line that is not allowing air to escape as the tank fills. Of the vent line is plugged off. Either way this will affect fuel draw and or will cause flooding. The vent line with a check valve in it is common, I use this system to keep fuel from draining out of the tank while the engine is being carried or is in a nose down attitude. The check valve must be removed or bypassed when filling to allow the air inside the tank to escape. Another note the check valve is oriented to allow air in as the tank level draws down, but will not let anything inside the tank come out. For those familiar with the YS pressure system. The check valve line is exactly the same except it is open to the air instead of attached back to the engine.

The DZ motors are different than all the others its doesn't use the pressurize fuel system. The pressure inside the tank should be Atmosphere and that is it. Another way to say it is Zero gauge pressure

Troy

gra95770

Troy,hope this is not too boring for you,I really appreciate your input hear as I have had no experience with these beautifull looking engines at all. But if I could explain,the tank has 3 lines,one to the pump,the other two inside the tank are similar to a pressure line off a muffler on a standard type engine.There is a T piece in one line which does a loop and comes off the filler line ,through a fuel glass filter and to the tank,and on the filler line there is a check valve,fuel will go in but not come out,is this the one you are referring to,the one to take off when fueling up

Troy Newman

Not sure I understand what you have there...

but here is how I setup my DZ motors

gra95770

Troy thanks a million,I will have a go at again tomorrow afternoon after flying,I will post the results,but I am a bit more learned now,once again thanks

JPal101

My Feedback: (32)

Troy, If I understand what you are saying, if you fuel the engine using a tee on the engine f uel feed line it will flood the engine. So, to eliminate that you disconnect from the fuel filter and plug it with a dot until it is time to start. Is that correct? If so, would a three line system ( one to fill, one to vent and the third to feed the engine) elimate all that? and the lines could then be installed inside the fuse.

Troy Newman

A 3 line system would be better, but we tried that and you can still flood the DZ style engine. In fact when the tank is full just sitting in the sun the fuel will siphon into the engine.

You need to close off the fuel line to the engines pump. Some guys choose a clamp, some have used small little ball valves from tettra and some keep the line disconnected until its time to start. No that the engine will flood if you don't take these step just that it could and when it does...well its very difficult to start.

Just a lesson learned from a pattern guy. when we are given permission to start our engines during the contest we have 3mins. If the engine is flood, I will almost bet you won't make it.


Troy

JPal101

My Feedback: (32)

Thanks for the info. I am just starting in pattern and did not realize the 3 min rule could make for a very stressful event if the engine floods. I will take your advise and close off the line until it is time.

gra95770

I have another issue and that would be fuel mix.It would appear that between 15% and 30% nitro is to be used,and between 20% and 24% synthetic oil. I have been told to use only coolpower low vicosity heli oil [red].Is this mix ok by percentage and by type.

Troy Newman

Yes I would use on the Cool Power low Vis oil. I think the oil is orange-red color. I don't know about this for sure as I alwasy get my fuel premixed from Cool Power.

I know you boys from Down Under get your oil from Cool Power and then mix your fuel. We are lucky to be able to be it premixed here in the States.

I personally would not run less than 20% nitro. You can but the engine is much happier and easier to setup with more Nitro. I choose 30% Cool Power Performance heli. I thought the oil content was 23-24%.....You should be fine at 23%. This low Vis oil is great in all YS engines.

Troy

gra95770

After running such a high percentage of nitro do you blokes use after run oil.

Zeeb

My Feedback: (41)

I'm not sure the nitro content has much to do with after run oil considerations. The problem with glow engines is that the alcohol attracts water. Then if it sits for awhile especially where there are significant temp changes you can get condensation in the engine as well.

The reason I switched to the CoolPower 30% is the claim that no after run oil is needed due to the formulation used in the fuel. I've never used after run oil in my 110's and all my models are kept in the house, but I was curious about the rust issue as well as how well I'd been running the first one. So after a year and about 6 or 7 gallons through it, I sent it in to Richard and asked him to give it a once over and do whatever it needed. He replaced the regulator (not unusual from what I understand) and said everything else was in great shape.

I'm sold on the CoolPower, great performance and no need for after run oil...

Troy Newman

I don't use any after run oil either and never have. I have for the most part lived in pretty dry climates. When the humidity is 40% we think its humid.

Back when in Colorado I used a one of the fuel brands made locally and had to replace my bearings with every rebuild (ring-bearings, orings, gaskets) about every 250-300 flights. I always ran my motor dry because if I didn't the fuel I was using would gel inside the regulator and it was tough to start the next time out. Especially if the temps were colder or it was a week or two between flights. Since switching to the CP I don't have this issue and things work much better. I'm not talking bad about a fuel brand, because it was a good fuel. I feel the Cool Power is better and I'm thrilled with its performance.

Since switching to Cool Power 30% heli blend I change the bearings every other to every 3rd rebuild. I had a prototype 160DZ test engine that I ran nearly 800 flights over the course of two plus years on original bearings. I changed them because they had so much time not because they were bad.

Another consideration is I fly almost exclusively off pavement. If you fly on grass or dirt runways then the motor will ingest debris. I would suggest an air filter. There as many ways to do this. Some commercial units are available or there are some smart guys out that that have used things like nylon stockings and the likes. Next step if you fly off grass or dirt fields is to change the bearings at that 200-300 flight range. The dirt and crap inside the motor will make the bearings rough. Its better to spend $20 on a rear bearing and 1 hours of down time rebuilding it than by new pistons, sleeve, ring, case, crank, head, valves, or anything else that could be hit by a exploded bearing. All this little bits of metal are not good inside the motor.

If you choose an after run oil use the stuff Dave Shad el sells at Performance Specialties. Its good stuff. I use it to assemble my engines and oil them before the first run.

Mastertech

My Feedback: (31)

Troy

A friend of mine ,OFB, has a Synergy with a 1.40DZ and I flew it today on 30% CP heli fuel and a 17/12 APC. It pulls the airplane ok but I think it's a bit much for the engine. What do you recommend for a prop?

Troy Newman

16-12 and
16.5-12 and
16.5-12W
15.5-12.5W is also another good one.

Just like in all the previous posts regarding RPM keep it up 8400-8600 and it will pull great. The 140DZ will load up with the 17-12 to about 8100 if its not to worn out.

Troy

gra95770

Troy, I am having trouble getting the Low Viscosity heli oil to mix up a brew to fire this DZ up ,hopefully today,but on the prop side ,I was thinking of trying an 18 X8 APC first up,is that a reasonable start point

Troy Newman

The bigger props are heavier especially the APC versions. This isn't the best of situations to load up the engine. I would say an 18-8 or 18-6 might be OK on 30% heli blend on a well broken in motor. But as long as you are turning 8400-8800 it will be OK on the engine and make life easy on the motor. I would look at maybe a 17-10 or back down to the 16's

I flew the 16.5-12W on my 140 DZ's and it was great and quiet too.

Troy

JPal101

My Feedback: (32)

While we are on the subject of props, i am planning on putting a brand 140DZ on an EXTRA 300 that weighs approximately 13 lbs. I was thinking of an 18X6 for 3D. Any suggestions? also what prop size can this engine comfortably handle.

JPal101

My Feedback: (32)

Sorry Troy, I thought you were talking about the 140 Sport, I see all the info on the prop sizes in the previous post. But, what do you think of that engine on the EXTRA

Troy Newman

You're going to have to try some props and let us know what works best for you. Keep the rpms up in the 8800-9000 range for 3D stuff and you will have much better luck than 8000rpm on the same model. You could load the engine down but its not going to like it especially in a 3D application and the settings become much more critical. Now you are talking about hovering and such where there is limited to no air flow and things start getting hot. Setting become very critical when it gets hot. Pumping lots of fuel and oil through the engine is going to help with the heat. Also a lighter load on the engine is going to help too.

I'll tell you the 16.5-12W on a fresh 140DZ will turn 8300-8500 on CP 30% heli. The 17-10 will turn about 8600. The 17-12 will turn 8000-8200. So an 18-6W or an 18-8 will be in this 8400-8800 range.

Troy

gra95770

Well,got the heli oil,my mix is 30% nitro,23% coolpower low viscosity heli oil,47% methonol.Low end screw is about level with the outside casing,and the mixture screw is out 1.5 turns,flick the prop and I get an occasional start for about 2 seconds and flick for another 5 minutes and maybe get another short burst,any clues,I have changed glow plugs,pulled the glow plug out and blew it dry,still no go

Troy Newman

Are you hand starting it?

Or are you using a starter?

What type of glow driver are you using?

Have you tried to open the throttle barrel a little more to get more air in. Is it possible its too far closed.

Some of these things are obvious....but a symptom of it won't start is tough to diagnose. If its popping that indicates it has fuel and has some glow. Maybe it doesn't have enough air? If you are not using an electric starter I suggest you do. Many of the single battery glow drivers don't have enough power to overcome a "wet" glow plug and get it to start. If it has a full charge and is a decent size battery in good shaoe it should. You need about 2amps to the plug.

Troy

gra95770

Troy,Got it started,boy what a power house,I think I need to understand this motor more,and work out how best to set it up,particularly the plumbing,I have this engine in a Yak 54,so most pies are covered by the cowel,and it definately floods quickly,so I will soldier on and see if I can get it to run sweet,thanks for your support, and on the clunk,what is the importance of the foam clunk,say against an ordinary steel clunk