I guess it is a 25cc.
Muffler bolts on, 4 screws in the backplate, output shaft is very short with the key cast into the flywheel (wide)
How do you put a prop on something like that?
Lots of work to do on that case. Do you know if CH makes an ignition for this one? Looks like it will be really light.
California emissions on the carb.

Another weedie to mess with.

A buddy of mine made the prop spacer so I am not sure what size to tell you to look for. I can find out tommorow and let you know. The spacer is not threaded just slides over the shaft. I have heard of people putting CDI on this one but why bother? Its very light as it is. As for the work on the casing....took me about 5 minutes with my edge sander and it was done. Be careful not to take to much of the ignition bracket off. One of our guys did and weakened it too much.

PROP NUT...I went to a fly-in several years ago near Greenville. I went 3-4 years in a row. I think it was on a Labor day weekend aways. One year there where so many at the fly-in it was hard to find a place to park. This was a big event then. I wonder if the club still has fly-ins there? Thanks Capt,n

I have only been a member for one year now. I have listened to many stories about the fly ins though. Havent had the time to attend one. They usually coinside with a family outing unfortunatly. (Dont tell my wife I said that)

Sounds like my prop shaft is different.

From the seal: I have 1/2" of taper then about 5/8" of threads. The shaft is 5/16 at the threads. When the flywheel is on, there is not enough room for a prop (even without the flywheel actually). The whole thing from seal to tip is about 1 1/8 or 1 3/16 or so. It sounds like I need some bar stock tapped for the 5/16 threads on one side and tapped for a prop bolt on the other. (or just tapped all the way through at 5/16)


Is that common? Or do I have an oddball or difficult child?

No idea if that is common or not. I have only converted the one. But yes, you do need a threaded spacer. Wacker engines could fix you up. I purchased one from him the other day (As my machinist buddy is in florida, darn those retired guys) because I was in to much of a hurry to wait for a free one. lol. He seems like a great guy, give him a call and I am sure he can tell you exactly what you need.

dirtypool
Yours does not sound to unusal. 1) On a flywheel with fins on front, chop them off flush to center washer contact surface. 2) fabricate your prop hub aft diameter at least same as flat on flywheel; front diameter large enough to get full contact on prop hub; 3) length is sufficient for the shaft plus 2x diameter of prop bolt 5/16 x2= 5/8" minimum; 4) try to tap completly thru from one side only; taper center OD to suit. Don't forget the Locktite RED when you assemble.

To dirtypool: Search wackerengines.com (new products) & carrprecision.com (model aircraft engines) for conversion parts. Poulon string trimmers seem to need a threaded hub extension to replace the flywheel nut. Poulon leafblowers have an extended threaded shaft, require a slip-on spacer.

Thanks for the great discussion guys. I wrecked-out the weedeater (man, did that feel good!) and found it must be the smaller size as the muffler has spring retainers.

Seems like the fins (backwards facing) could be reduced a little. Anybody got a favorite technique for rebalancing the flywheel?

And, something I've wondered about is just how necessary all that cooling fin area is. Am thinking of rounding-off the corners. Also, wondering if the project warrants installing a coupled ignition system???

On the flywheel, I took some pliers and broke the fins off. Then ground the flywheel smooth with a die grinder.

I balanced the flywheel with a High Point Balancer from B&B. But a Dubro should be just as good?

There's a cast in key. On that side push the flat side of your arbor cone up against the flywheel. On the other side, use the tapered end. Use a die grinder to get the flywheel in balance.

There's a guy on here that mounted his flywheel against the chuck on his drill press and spun the flywheel against some sand paper that was on a flat surface.

Enjoy,

Jim

Sorta like my routine on the flywheels. Use a 4" cutoff wheel chucked in the press, set the desired cutoff height of table, belt the press to high speed, and slowly rotate the flywheel on the table. Here is some pics[link]http://www.rcuniverse.com/forum/m_1821862/anchors_1821862/mpage_1/key_flywheel%2Cdrill%[/link]

How do you hide a link? Don't think my attempt worked.[>:] copying properties of post did not work.

Do a search for thread: Flywheel mandrell for Homelite 25/30?

any conversion ideas for an early gen Ryobi 31cc?? I have an older model that I used in the yard for a few years before the muffler bolts loosened up and then broke off in the head. I've gotta buddy who is a machinist who can probably bore out the muffler bolts, but I'm wondering if the motor is even worth messing with. It runs like a beast and screams like a banshee with no muffler.

I thought about a grinder wheel in a drill press, until I considered the consequences of a shattered wheel [X(]
I just Roto-Zipped the fins off and then rebalanced. Quick and easy.
Pete

At this point, I'd like to caution anyone with ideas about using a stone grinding wheel to cut or re-shape aluminum.

The aluminum is real soft. It will pack itself into the pores in the stone. It can cause a grinding stone to shatter or explode.

You need to use a carbide cutter, sand paper, or a special ablative stone made for reshaping aluminum.

The ablative stone sheds it grinding media rapidly as it cuts. Therefore the packed aluminum is shed right along with the grit.

In my die gringer, I used a A11 carbide cutter.

Enjoy,

Jim

just my 5cents worth for info ,iam in the uk bought a mccolock 21 weedeater stripped off all unnecesary bits but left every thing standard except opening up the exhaust mufler exit .trimmed of the fins on the fly wheel,using the vertical drill method .used a scott baldridge conversion kit and fitted it in a cabin type large(95")wingspan plane that has a dry flying weight of 16.5ib .the engine fitted with agraupner 16.8 pulls 6600 to 6800 depending on the day an gives the plane almost aerobatic performance ,it (the plane) has to work hard ,we have had wind varying from 15 to40 mph nearly all winter and she takes it like good one

HI I JUST CONVERTED TWO 18 CC WEEDEATER LITES AND DID THE FLYWHEELS WITH A 4" BELT SANDER. PLACED FLYWHEEL FACE DOWN ON BELT AND JUST KEPT ON TURNING IT UNTILL THE FINS WERE WHERE I WANTED THEN. AFTERWARDS BALANCED IT WITH PROP BALANCER. THIS IS THE SCECOND AND THIRD ONE I DONE. FIRST ONE FLYING ON BALSUA USA INDECKER. FLIES GREAT AND GET LOTS OF GOOD COMENTS ON IT. ITS ALL IN HAVING FUN.
BIG AL

Hey guys,

I did a conversion on one of the 21cc featherlites this summer. I'm really pleased with the way it came out. I built a CDI ignition setup for it (really, the ignition was my reason for starting the project, the engine was done just because I needed something to put the ignition on), as well as ported it to g-23 timing specs, cut the base of the cylinder for a little more compression, and bored the carburetor to full diameter along the full length (got rid of the casting around the smaller hole from stock), as well as a few other small modifications (velocity stack, etc). The boring of the carburetor required me to go in and resize the top and one of the middle fuel holes into the venturi body in order to get the engine to run correctly throughout the rpm range. Spark plug checks look identical all the way from idle to full rpm, so I think my mixture is staying pretty constant. Would have been nice to have a 2 needle carb and not need to do this, but tuning with 1 needle is handy as well. Not that gas engine ever seem to need tuned Lots of work in all, but it was enjoyable, and I now have a free engine (flywheel key sheared, engine was given to me) that will turn a 16x8 master airscrew at 9200 rpm, according to my globee tach. Quite a sight better than the stock 6600 rpm with the same setup. I'd guess this is probably quite a bit more work than everyone is looking for in a conversion, but I just wanted to let you guys know what can be done with these engines. Mine's never skipped a beat, and always starts first or second flip when it's primed right. Excellent engines.

I just bought two NEW weedeater power heads for 25 bucks each on E-Bay this week. I just got them today and it looks like an easy conversion. It's the model FL ex or maybe xe, anyway, it's the newer weed eater engine. Looks like the hardest part is going to be trimming off some of the excess aluminum block casting that was used for bolting the plastic houseing onto.

The seller on E-bay is listed as "thenashvilleplace" .Wacker Engines sells a conversion kit for $35 and the muffler for $25.

.

Hello every one! I am getting ready to do a conversion engine. But I need a little help! I have a Katana 1.60 that needs a gas engine! What do you guys recomend for a conversion engine to replace an OS 1.60? I am very good with my hands so converting it will not be a problem. Also where are some of the GOOD places to order the conversion kits from?

Thanks
Baker

Chainsaw engines like the Homelite 45 or Poulan 42 or 46 would be fine.

Source for hubs and mounts...

http://wackerengines.com/

For battery powerd electronic ignitions...

http://www.ch-ignitions.com/

http://www.rcignitions.com/

Enjoy,

Jim

w8ye
I thought a homlight 45 would be to much for a 1.60 sized plane? I thought I needed a homelight 25cc weedeater Motor. I will have to take your advice on this though! So I need to go get a Chainsaw with a Homelite 45cc motor?

Thanks
Baker

Baker: Where can I get a good price on the Kantana like you have? Thanks Capt,n

I bought my Katana 1.40 from www.cheifaircraft.com for $200.00

Hope this helps
Baker

My friend is flying his katana with a ryobi 31 flies great!