Mac/Echo? Is it worth it?
 

I have a weedie that says McCulloch on the rewind but the whole thing looks like an Echo to me. Only info on it is a serial # tag on the bottom that says 400035B and then some #s that look like the serial # itself. Can you tell me which kind of bearings are in it? Will it make good power? Has 100 lbs. compression. Spark is good. I tore down an Echo that looked just like it,Echo 100, and it had points. But the engine was shot, no compression and scored. thanks for any info; Jim

RE: Mac/Echo? Is it worth it?
 

It's not at all like my McCulloch 28's and 32's

Enjoy,

Jim

RE: Mac/Echo? Is it worth it?
 

I have one the same, and although it is called a McCulloch, I believe that it is a 21cc Kioritz, ( Echo ), - seems that this particular model was sold under many different brand names. Mine has an electronic ignition, not sure about the bearings, (but probably ball).
I have only used it as a weedie - as yet!

RE: Mac/Echo? Is it worth it?
 

I finished tearing down (the bad one) and cutting for the most part on it and found it was marked 16cc E under the exhaust port. Obviously one of the older 16cc units. But I will weigh it bare anyway just for courosity reasons. I was hoping to use it as a pattern for future components. I have a few more of these Echo and Mac weedies so I guess I will check them out for size. I noticed some have rounded design fins and some are square. Does that mean anything as far as size of the engine? Here is what it looks like at the moment.

RE: Mac/Echo? Is it worth it?
 

You sure that it's the same as the one in the first picture? I don't think so! When you strip the yellow one I think you'll find quite a few differences. ( I could be wrong).

RE: Mac/Echo? Is it worth it?
 

Your right it's not, sorry for the confusion. The first picture is the Mac unit. The one tore down is a John Deere/ Echo 16cc. I wanted to compare it to the bigger ones so I tore down a couple more today. A Mac and an Echo. They look the same. like the one in the first picture. They also have a square fin setup. The 16cc unit has a round fin setup. Actually the one in the first picture I got running. Just needs a diaphram kit in the carb as it doesn't pump too good, the pump check valves are pretty stiff. Is there by chance anything a guy can soak them in the soften them up to keep from buying a kit? I want to mess with these and see how light I can get one down to. I will weigh one at work on the postage scale and let you know. Does anybody already make mufflers for these litttle engines? I will be needing a couple. thanks again for any comments.

RE: Mac/Echo? Is it worth it?
 

Hey If you want more of those engines or just parts let me know! I've got boxes of them. Round fins . square fins, Mac's, Echo's and so forth. All made by Kioritz and all pretty good quality.........Bob

RE: Mac/Echo? Is it worth it?
 

What are you using them for?

RE: Mac/Echo? Is it worth it?
 

I have been selling weed eater engines to R/Cers on Ebay for awhile now and this type isn't a good seller. When I get to clean out saw and mower shops I take everything and that includes these engines. They are pretty plentiful at yard sales also. At any rate I have quite a few and there are lots of subtle differences in them not only in terms of cc but in transfer port, intake and exhaust placement and size............Bob

RE: Mac/Echo? Is it worth it?
 

I weighed the engines on an electronic postage scale. The 16cc unit just as it is in the picture but without a spark plug is 1lb. 10oz. exaclty. No carb or muffler or ignition or prop hub.
The 21cc unit was 1lb. 13.5oz. with sparkplug. No carb,or muffler or ignition or prop hub. I will weigh the plug to compare.
Am hoping to get the 16cc unit light enough to try in a Sig 4* 60. But maybe it won't happen. I don't want a rocket just a good cheap, and cheap to run sport engine for it. Right now it balances good with a TT90 4stroke and a 16oz. tank empty. Am hoping I can go to a smaller tank and use the difference in fuel weight to compensate for the battery pack needed for ignition. Or perhaps I should check into that glow on gas thing in one of the other posts.
If the 21 has enough power it may go into a Sig 4* 120. Wait and see.
Here are pictures of the 21cc unit.

RE: Mac/Echo? Is it worth it?
 

EAGLE FLYER, I have an engine that looks just like that, (the weedeater too) I just started another thread today, and then came across this one. I don't know much about it, and I'm wondering if I'm wasting my time on such a small engine. I noticed you cut down a great deal of the casting, and you have no mount for the ignition coil, do you plan to use electronic ignition? if so which one. I am in the process of grinding mine down, and I just can't leave enough material to make it strong and look good (to hold the coil) the casting just has too many odd shapes, and divots, etc, I'm afraid if I make it look good (and light) it won't have enough strength and the vibration will crack it. Also the flywheel mounts backwards compared to others, looks kinda strange. I want something for a Stingray 120, just for touch and goes and such, it doesn't need to hover, but I'm wondering if this little guy will be enough. check out my pics [link=http://www.rcuniverse.com/forum/McCulloch_conversion_info%2C__Pics/m_1667248/tm.htm]http://www.rcuniverse.com/forum/McCulloch_conversion_info%2C__Pics/m_1667248/tm.htm[/link]

RE: Mac/Echo? Is it worth it?
 

The 16cc Kioritz is a cute little guy, but really doesn't have enough power. I used one once, and with modifications got about 6500 rpm's with an APC 15 x 8 prop. It flew my Big Stick fairly well at sea level, but didn't have enough poop when I moved to an elevation of 4500'. I would consider the 21cc to be a minimum.

Have fun,
AV8TOR

RE: Mac/Echo? Is it worth it?
 

Uh oh :( How can you tell the 16cc from the 21 ? Does the 16 have round fins and the 21 square? Maybe you can help me determine what I have, (click link two posts up for pics)

RE: Mac/Echo? Is it worth it?
 

I'm thinking that the 3 hole mounting, and the "no wrist pin bearing" are telling me that it is a 16cc. Mine had a "16" cast into the cylinder. The only way to be sure is to measure the bore and stroke. On the ones I was playing with, the 16cc and the 21cc had the same stroke, but the 21cc had a larger bore. Sorry I don't have those dimensions for you. I actually converted my 16cc to a 21cc by changing the cylinders, but it was a very involved project that I don't recommend. Better to use a 21cc or even better yet a 23.6cc or 25cc Echo/Kioritz to begin with.

To determine the size, the formula is BORE X BORE X STROKE X .7854. The total stroke is two times the distance from the center of the crankshaft to the center of the crankpin where the rod goes. If you do the measurements in inches, you will come up with cubic inches, which you can then covert to cc's by multiplying by .061.

Hope this helps,
Please check out the thread "Don't forget the Echo..."
AV8TOR

RE: Mac/Echo? Is it worth it?
 

I see another difference, In the pics above, it looks like the crankshaft is straight, mine is tapered, and the flywheel has a cone shaped hole in it. AV8TOR1977, I think you mounted your prop directly on the crankshaft, with no "conversion" parts needed, in my case, with the taper, that isn't possible, strange how the engines are so similar, but so different. Maybe this is another diff between the 16 and 21 cc versions ?

RE: Mac/Echo? Is it worth it?
 

Eagle Flyer,
your 21.2cc looks like the same engine that DougT is working on, check out the "echo on a funtana thread" for tips on making this engine LIGHT.


dave