tater1

Ahhhhh Sucess,found a leaky gasket on one cylinder,cleaned the carb,we checked the plugs it appeared that one cyl was running lean,tried partial choke and the engine ran at full throttle,after shutdown I then left the choke full open and the engine ran at full throttle,maybe a partial blockage in the carb that cleared itself,now both exhaust are normal and not just smoky on one side.anyway it seems to be running like a champ,now to maiden the bipe.

PlaneKrazee

My Feedback: (14)

Do you have a tach and can you get to the fuel line while it's running to pinch the fuel line like a glow engine to see if it is rich or lean? It does work. You may find the carb hign speed jet is plugged. If it runs ok up to 4000 rpm sags and quits the high speed jet isn't passing fuel. This was a problem with some of the first DL50 engines.

PlaneKrazee

My Feedback: (14)

For those who bought this engine new, was it run before you received it? Did it come with the velocity stack? Were the tops of the pistons discolored from running or exterior of mufflers stained with oil around the mounting screw lugs?

qldviking

Hi I have one of these dzy48's, looks nice and run well on the stand. fired right up after priming and 3 flips. only gripe I have is the mounting lugs are weak, I broke one when it dropped on my lawn from 22inchs of my bench. otherwise after 3/4 gallon it spins a 20x8 bolly prop at 6950. I am making a 1/4 inch plate to bolt on the back of the motor casing using new longer bolts. the bolts on the motor look cheap and nasty so will also replace them. looks to be a good little motor otherwise

PlaneKrazee

My Feedback: (14)

If the case was machined billet like Andrew Coholic stated in his December 2007 Fly RC review you wouldn't have this problem. Either he got a engineering sample or he can't tell the difference between cast and billet.

When you think about it, why would any manufacturer bead blast a machined billet case?

WILDGAS

RCDUDE7, Do you have more pictures of your Pitts with this 50cc twin? I would like to know How can It see with cowling

walt892

Mine is down for faulty ignition unit. Flew the Pitts 3 times.... flew nice then motor crapped pout.

Lousy compression but still hand starts. Wonder why???

Are you the person who got rings made from Bowman's Rings??

walt

respond to [email protected]

rctom

I can tell you this much. THe DZY-100 twin is an absolute jewel.

I bought one to see if it was any good. Bolted it on a plane and went flying with it, I haven't had to do a thing to it. It starts in a few flips, idles very smoothly and reliably, spins up a 27-10 with plenty of power to haul around a 28 lb. Extra with unlimited vertical.

I have about 30 flights and well over 5 hours running time on it and it has never missed a beat, its performance is the equal of a DA-100 at half the price.

Now, not all DZY's are like this, the smaller ones seem to be less complete, but this 100 is a real peach.

TF

PlaneKrazee

My Feedback: (14)

Frank Bowman made me a set of rings but I haven't run the engine yet.

jrjohn

My Feedback: (24)

Tom, how about getting some information out on this engine. Weight, Power, RPMs , pictures, ect.... I've heard that DZY builds some awsome twins.

rctom

OK here you go.

The weight including prop bolts and washer, carb and spark plugs installed is 5 lb. 11.5 oz. on my digital postal scale. The ignition is another 3.5 oz. putting te all up weight without mufflers at 5 lbs. 15 oz.

The mufflers that come with the engine weigh 4 oz. each.

I am offering the engine with an upgrade to the carb, shown, with good arms. This alone will save an hour or two of fooling around trying to hook up throttle and choke to servos. The upgrade will be installed free on the first few engines I sell.

On mine I measured the power in the first couple minutes of running time, it was turning 6300 rpm fresh out of the box but I don't recall what size prop I was using, it was a bunny prop, not a Vess. Flying, the engine hauls around a 28 lb. plane with authority, I was using a 27-10 something else and it flew great.

I has canisters on mine, 2x KS86-4. These seemed to stifle power slightly, it made more power on the stock mufflers. But they are so quiet I loved them and it still had plenty for any type of flying.

The DZY-100 is remarkably smooth, I'd have to say it's the smoothest engine at both idle and at full power that I have used.

Some of the photos shows the very nice cast case, which appears to be the only significant deviation from a straight DA-100 copy.

TF

Mitsu1

My Feedback: (13)

Tom, is the DZY 100 prop hub bolt pattern the same as the DA 100? I ask because there are some Chinese twins coming with a prop bolt pattern that's different from anything else, and this makes prop sharing with your other engines impossible and causes you to have to buy new props.

rctom

I'm glad you asked.

The standard DZY has a prop bolt circle that is about 1mm larger diameter than a DA-100. It's so close it looks like it's the same but the props won't bolt up without enlarging the holes. This is one of the things that had held up my decision to sell the engines, I knew this would be a problem.

DZY has agreed to change this for me. I have sent them a prop drill jig with instructions to make a hub that will fit it. They promised that they will be sending me new hubs for the engines that I have in stock and the one that I have sold, they say it should be ready in a few weeks.

I will provide the replacement hub to anyone who buys an engine, and a free 26-B prop to use for break-in so you don't have to spend money on a prop that can't be used on any other engine.

TF

Mitsu1

My Feedback: (13)

Yep, I have a RCGF 100cc engine that has the same bolt circle as your DZY. We too are talking to the factory to try to get this addressed. Not sure why they have this larger circle, but hopefully they'll all start to follow the established US standard. Buying engine specific props can be expensive.

rctom

At first my plan was to simply drill and tap new holes in between the original holes, that would have been easy. But when I got the hub off I found that they had already drilled lightening holes in the gaps from the rear so there was no material left to tap into.

I hate when that happens.

TF

walt892

Well folks, an update regarding my DZY 48cc Twin. Engine ran fine during rather extensive and careful break-in. Mounted in RCguys Pitts biplane (nice ARF) and after 2 flights, the ignition failed. So, a couple months down trying to get a replacement. Was wrong plug size. So got credit and ordered one from a hong knog source.... jettechmodels.com. Nice outfit. Good prices.

So, motor fired right up. Ran beautifully. Guys at the field kept commenting on how good the engine sounded and ran. Flew 6 or 7 flights. Hand started easily as long as the ignition battery was up and a hot spark was provided. Engine compression lousy..... lousy, mushy from the very start. Well, other day, went to fly and could not hand start the motor... not sufficient compression. So, I have given up. Sent the cylinders with pistons to a custom riing maker. Maybe I can get this thing to produce some good compression. If so, I will have a good engine. The cylinders looked like they were wearing in well. The tooling marks were gone and the walls looked really good.

Wish there was a DA 50cc twin !

Are there other AFFORDABLE 50cc twins made? Any suggestions?

Thanks,

Walt
Glenville, PA USA

rcdude7

My Feedback: (264)

That is a shame that you will need new rings on a new engine. I have a DZY 48cc twin in a GP pitts, it is a perfect fit in this plane. I have not yet run the beast, but I'm very close to finishing this project.

What size prop did you use on your DZY? Would a MENZ 21X8 be too much for this engine?

I have two other small twins, a 3W-48 that is very powerful, and a RCS-44cc that is similar to the DZY in power with a rear carb and rotary valve induction.

Mitsu1

My Feedback: (13)

Well, ... you're in luck. There is an affordable alternative that is a real performer, a quality piece of work, and is sold and serviced right here in the U.S. The RCGF 50T is just that engine. $479.99 www.zrcgf.com