WacoNut

Anything to make it run/start better. I will see if they have that carb.
Thanks!!
Anthony

WacoNut

I put a half dozen flight on my Cub over the weekend with the 56 on it and it is starting better. I just realised I had accidentally installed on of my 6v packs for the ignition that went to my Waco with the 3W 157 in it. I have several different 4.8v packs. What size pack do you recommend, how many mAh?
Thanks!!
Anthony

RCplanman

My Feedback: (16)

aussisteve, Need your helpplease. I have the 20cc that Henry sold. I also have the next larger size [ I think ] which I understood was 26CC. I've read people talk about a 28cc RC AREO. Would you happen to know which size is correct ?
I have a 16 lb. Bucker Bi-Plane & am trying to decide which engin to use. Both are new except for the break-in.
Thanks in advance for your help.

Bill AMA 6416 rcplanman
WB 126

aussiesteve

Hi Bill
The 20cc and the 26cc sold by Henry were made by RCGF. The 20cc is actually 23cc and the 26cc was available in a few configurations, including a 28cc but stil made by RCGF. Most of those apart fro the very later ones had cast (and possibly tumble polished) crankcases.

The 28cc sold by Henry was made by JC engines and was what was known as the JC 28 "Evo". I has "JC" on it either on a side plate on the cylinder or on the CNC Machined crankcase.

Now for the confusing part. It would depend on which "26cc" you have. If it is the early one (look for slanted fins on top of the cylinder head, a screwed on side plate on the side of the cylinder and fairly thin cast lugs on the crankcase), the power is not much different to the 20cc. If it is a later 26cc (no slanted fins on the top of the cylinder and a centre plug) it is much beter power than the 20cc.

My suggestion would be to use the 26cc of the two on that plane. The earlier 20cc's had a few running issues in the air caused by carb springs etc. A change of carb diaphragm return spring to a Walbro one (Sorry, I don't remember the actual part number but maybe others on here will know it) and a remote vent tube tend to overcome those running issues.

I hope that helps.

Steve

RCplanman

My Feedback: (16)

Steve, Thanks for your reply w/info. Sorry for my delay in responding, the server ? was out aall morning & was unableto get to RCU, maybe they are the server.
Re; my engin. Frist I've pulled a G-23 off the shelve which should pull the 16 lb. Bi-planeyou think?
My 26/28x ? Aerovat has the flat fins, center vertical plug,ploshed crankcase w/jc engin engraved on the back plus abolted plate
with jc engin engraved on it. Has a Walbro carb #793A or 921 was also closeby..Is that enough info. to I D the engin ?
Thanks again for all the help & advice you provide to the forum,

Bill

aussiesteve

No worries Bill
First up, the G23 will be very adequate power for that plane.

The engine you have there is a JC 28 "Evo". B tthe first version of the "Evo". (The 793 carb is what tells me that - later ones had an 805 carb).
Whilst they are running, they are as strong a running engine in the size range as has ever come out of China.

Couple of "Gotchyas" on the engine.
1 - with the 793 carb. If it has an external pulse line between the crankcase and the carb, make sure the internal gallery between the carb and the carb mount is blocked otherwise it won't pump too well. JC Engines supplied a lot of these with the 793 carb that were very troublesome because of this (Many losses were made by the distribution chain downstream of Kevin Jiang because of them).

2 - It will prefer an 18/6 prop.

3 - Replace the diaphragms in the carb with some new ones. Many of the engines were sent from the factory with bad diaphragms in the carbs. Use a D10 carb kit and use either the tan colored (Teflon) or Blue colored (Acetal) pump diaphragm.

4 - Don't run it over rich. Tune it by leaning it to best performance as it will be near impossible to wind the needle to a rich position where the enigne revs will drop.

Don't try to run it too lean on oil. No engine likes that. My personal choice is 40:1 of a good synthetic (Redline, CastrolTTS, Mobil1 2T, Stihl Ultra HP) or 30:1 of a good Mineral oil (Pennzoil air cooled is a good choice there - not sure what else is available in your area).

Gap the plug (Genuine NGK CM6 of course) to 0.020" (Thickness of a Hobby knife blade).

If you can get hold of an 805 walbro carb, bolt it on and the engine will transform to a much nicer engine that will prefer an 18/8 prop. When I refer to props, I used Xoar laminated props.


I had a lot of fun with the JC 28's when I had them in my planes. I don't have any left in them now but they were a lot of fun whilst they lasted.

RCplanman

My Feedback: (16)

STEVE, WOW, what a lot of information .Tons of thanks.I'll try to follow ALL of your suggestions.

Bill

RCplanman

My Feedback: (16)

Steve, My plug gap was off. I'm unable to find a 805 WALBRO carburater.Do you have a sourse there or else where? Why is this carb different then the one I have?
Thanks,
Bill

RCplanman

My Feedback: (16)

STEVE, MIGHT YOU KNOW WHERE THE 805 WAS USED?

Bill

rt3232

My Feedback: (6)

New question's is any one running a YDA-56 and if so what props are you using, also what is the weight of the bird are you flying ?

I am still trying to figure out good prop for this engine and in 18-+ lb Weeks Bipe no 3d just normal sport flying,

list of props tried so far all Xoar,s
20 X 8 just above stall speeds about 6700 rpm
20 X 10 better but still a bit dragy same rpm's
22 X 8 still better but vary limited virtical tight loops only about 6500 to 6600 rpm

Thanks in advance for any sugestions

Cheers Bob T

AA5BY

Bob... I'm curious to what answers you will get to your question.

MTK

OS33GT turns these props at over 7.4K. The 20x8 is closer to 8K. Is this particular 56 really this weak?

rt3232

My Feedback: (6)

Ok guys

I was told this engine was not designed for HI rpm and the best of the torque curve was in the 6300 to 6700's so don't realy know about week.

But this is what I got on static thrust today using a farly good fish scale and calabrated with a none 5lb weight

22 X 10 was at 15,2 lbs
22 X 8 at 17+ lbs
20 X 10 at 16 even
20 X 8 at 15.5 or .6
One outher thing I did not mention was this engine only has about 40 to 60 min of run time so it may get better, So will just go with the 22 X 8
for the rest of this season, as the engine runs great good transition and nice idle.

so still hope to hear form any one running one of these engines


Cheers Bob T

AA5BY

The 22x8 with 17+ lbs of pull ought to be pulling 18+ lb plane with good authority. Evidently what it's not doing is unloading in the air and gaining many more rpms and any further pull and that may be mostly due to the drag associated with a biplane.

Like MTK, I'm wondering if the engine is a bit anemic. I've a 35cc in a new installation on a 16.5 lb plane with 8' wingspan running a Vess 20A @ 7400 and it pulls well with large loops and high stall turns.

It might be that a higher torque prop would help deal with the drag on the slower plane and I note that no 6 pitch props were tested. Perhaps a 23x6 if one were available. You might try a Vess 23A... the A is for their higher torque props for slower heavier planes.

AJsToyz

.

BadAzzMaxx

Any 50 to 60cc engines should give 25-30 lbs of thrust, If not they are dudes no matter what is said.

Here is a video that is a little over 4 years old and a 53cc engine.

http://www.youtube.com/watch?v=oKCfkTZ259E&feature=plcp

http://www.youtube.com/watch?v=u7hn80t3UQ8&feature=plcp

Milton

JVB

My Feedback: (2)

Need a bit of help. I have a JC28 Evo with a Walbro 805. Lucky me, it runs great. Last Thursday, had two flights. Went for the third and it died. Luckily I got it down fine. Took a look and the high speed needle was gone. Where can I get a new needle and spring? Thanks.

John VB

laryboy

My Feedback: (2)

i took apart my jc 28 to clean carb when i looked inside the reed block. i was expecting to see a little window with material screwed onto it to allow fuel and air in but not out. i didnt see anything at all.nothing in there . any explaination?....................larry

BadAzzMaxx

??????? Also

Picture

Do not see how it could even run that way.

Milton

laryboy

My Feedback: (2)

me stupido ! pulled block apart...now i see the 4 metal flaps...thanks for your input...........larry

R/C Addiction

Speaking of reeds...can anybody tell me if the new JC 30 reed block assembly is the same as the reed block assembly that came with the JC 28? If they are of a different design, are they interchangeable? I have a JC 28 that I bought from Henry of R/C Aero which has the tilt and slow down issue. It used to be a tilt and die issue. I installed a replacement reed block assembly that I received from Kevin (through Milton) and the problem seems better but hasn't been completely eliminated...I have also replaced the carburetor, if I can remember right with a DLE 30 carburetor, just to eliminate that as a variable. I work overseas and found out about the replacement program too late for that to be an option. The engine is installed in a Mud Duck MKII so I'm not hovering or anything but would like to resolve the issue....the engine runs pretty well otherwise and has adequate power for what I need...

rt3232

My Feedback: (6)

Just an up date on the YDA-56 out flying the bird today and seemed to be some inproved with tge 22 X 8, next time will do a little fiddlingwith the carb and see if I can get a few more rr's

Cheers bobt

norbert001

The JC-28cc Evo and the JC-30cc Evo do share the same reed valve.

Paul

Michel

Hi

I,ve been reading the posts on the YDA-56 ,.............. I have one . And the RPM readings , are not very good at all .

With an Xoar 22X8 prop , all I get is 64/65 , RPM , and it runs , " HOT " .

If I change the carb to a " HDA-245 , will it run better .

Any help to get more power out of this engine would be greatly appreciated . At this point I am very , very disapointed in this engine .

Michel

JVB

My Feedback: (2)

I was flying my JC 28 Evo this weekend. The engine has run flawlessly to this point. During my first flight, it started sounding different, so I landed. The prop hub was loose (had play from side to side). The front bearing was spinning in the housing. Tore the engine down today and the front bearing fell out. You could easily see that it had been turning in the case. The internals of the engine were perfect. Plenty of oil, etc. Piston looked great. I probably have no more than two gallons of fuel through it. How should the crank be removed from the rear bearing? Is the case trashed as I assume that a new bearing will not fit tightly anymore? If I need a new case, does anyone still carry parts for the 28? Thanks.