I just pulled an engine out of a Homelite ST-200 Weedwacker. Its an old model made in the late 80's and it looks quite different than the typical 25cc wacker engines. It has a side mounted carb, but it has a rear exhaust on it. It is pretty small and light and from the model of wacker I am guessing it may be 20cc's? Would any of you have any idea what I got?

What is the model number of the complete device? It sounds a lot like my 23 cc 1980's machine? Do not despair they have a lot of power, give us more info if you can, you may have a power house, or a mouse , let's find out.


Fly the airplane first.

Lee K5MRC

Blackbaron:
1.9 cu. in. or 31.2cc

Is it a good canidate for conversion?

Black Baron,would you be able to post a picture of this engine for the guy's to have a look at?Sounds very interesting and I'm kind of curious to know myself what the displacement might be.

Blackbaron:
Havn't done that particular engine. Looks like a good candidate but you need to check out a few things. the picture in the manual shows only one bolt holding the muffler on but you may be able to hold it on with springs like the Ryobies. Does the back of the motor have tapped holes to bolt on a motor mount plate? From the pictures, the shaft turns in the right direction. It has needle roller brgs. for the main brgs, like the Quadra 35-42s which have worked for yrs, in them.Ball brgs. are better but heavier.. Give it a try and let us know how you make out. Hope this helps.

It might be a challenge to mount though. I remember it being a powerfull and reliable weedeater until the trimmer head trashed out. It had been two years since it was used and I just put some fresh gas in it and it fired right up. I wanted to make sure it ran good before tearing it apart. It runs really strong.

I have one of these, bought it partially converted as a 25cc, finished it & it runs well, but not nearly as powerful as my newer 25cc Homies. With an 18 x 6, the newer ones will turn 7100 rpm, the best I could get out of this one with the same prop was 5800 using identical Walbro carbs & (I believe) Wackerengine mufflers. A 16 x 4 on it gives me 7500 rpm. It does weigh considerably less than the newer Homies, tho.....I'm thinking of a lightly built WW1 bipe for it.

I hate to resurrect old posts but I just got one of these. Its got an angled plug unlike the normal 25 and 30cc homies.
Anyone else have info on how they are?

It's not a HK-16 is it? I have one of those and it's not suitable for aircraft use....at least to me. Mine has a rear pull start which has a points ignition system behind the starter mechanism. The carb and intake are larger than the cylinder.....

I believe there were other larger HK models.

Nope it's an ST-200 and the cylinder is quite large.
I haven't torn it down yet as its a functioning wacker at the moment.
This thing has incredible compression!!!!

What you have is very similar too if not the same engine as the small Homelite chainsaw series XL 2 and Super 2"s. They range from 26cc to a high of 33cc with some variations within that range. They are a reed valve engine and are fairly durable. Earlier ones had points later were all electronic. Parts are almost interchangeable between the models. There are probally better choices for conversion......Bob