Tmoth4

My Feedback: (1)

This is the hole that can be plugged to increase performance on 25 and 30cc Homelite weedeater and blower engines. I tapped it part way in and put in a set screw. Plugging the hole increases the compression. I don't know what the hole is for. My guess is it's for easier starting or emissions reasons.

Jim

pastorjody

I wondered if that was the hole that I had been hearing about. How much more performance does it give? I have a 25 flying a 1/4 scale H9 cap very scale with stock muffler...very quiet and scale-like. 16-10 airscrew classic @ 7600. Really pleasing airplane.

Bernett

Thanks for the picture. My 30cc engine, which came from a john Deere trimmer doesn't have that hole. I was assuming it's a homelite engine. I wonder why they made different versions of the engine?

Paul

Tmoth4

My Feedback: (1)

Bernett,

Maybe your engine isn't a Homelite. I got a 33cc engine out of a 14" Homelite chainsaw and it doesn't have that hole and it has the bigger throat carb on it already. It's a very strong engine in comparison to the trimmer and blower engines.

I would guesstimate that blocking the hole adds 10% more power and the bigger carb adds another 15%. I have a 25cc Homelite blower engine on a 15# bipe and it hauls it around nicely. I put the bigger carb on it and I'm using an 18-6 prop.

Jim

TnCubman

I was wondering is weedeater brand engine to heavy for a 60 size cub I know they don't have much power but i figured this would be a light enough plane to make up the diffrence. I looked at one on sale at walmart for $49.95. If it is I plan on ordering the conversion parts from carr precision. I haven't bought it yet just wondering. If not I'm gonna purchase a 1/4scale bird. Thanks for your time. Maybe a Rearwin Speedster.

Tmoth4

My Feedback: (1)

I'm not familiar with the weedeater. The gas conversions are for planes in the 12-14 lb. range and are too big and heavy for a 60 size plane.

pastorjody

I am working on a 1/4 scale cub with a weedeater 21 but I haven't flown it yet. I think with a 1/4 scale cub the weedeater might be a little light power wise but with a bigger carb and optimum prop selection it might be very scale. You will be surprised at how much heavier the gas engines are in comparison to what you are used to but when properly balanced you will also be pleasantly surprised at how much low end pulling power they have and how well they fly at low speeds that would scare a glow engine pilot. Look for a larger than 60 size floater that has at least 1000 square inches of wing and weighs in the 10-11 pound range ready to fly. Perhaps one of the old timers? They fall into that category.

Tmoth4

My Feedback: (1)

Sometimes the heavier gas engines are an advantage when you have a plane with a short nose. I have a 1/5 sc. WACO bipe and a couple of 1/4 sc. WW1 planes with Homelites and they balance without any lead in the nose.

Jim

rsrogers

My Feedback: (10)

Back to the original subject, the hole is for emission reasons. The little hole allows the vacuum created by the down stroke of the piston to suck some of the vapors back into the cylinder for "re-use". I have converted alot of these engines and most all of them have the hole but depending on where you live it may or may not have a set screw type plug in it from the factory. Being from western N.C. all the ones I have done are plugged from the factory. If your hole isn't plugged you will notice alot better RPM & performance if you plug it.

Keep'm Off The Ground!!
Steve

Tmoth4

My Feedback: (1)

I wondered what that hole was for. The compression increases quite a bit when you plug it and it feels more like a normal engine.

Jim

frequent flyer

My Feedback: (6)

I was reading what you guys were talking about, the conversion of 25cc engines, sounds interesting. I've been buy comerical gasers and boy, they are expensive. What is involved to make a chainsaw engine into a airplane ready engine? How much does that cost you? There are lots of old chainsaws and weed wackers around here are they good or do you really have to start with a new one. L'm pretty good with engines, rebuilding and stuff like that but what other parts are needed? Can you buy them somewhere? Is there a website that has them?

rsrogers

My Feedback: (10)

You can check out RS Engines at http://takeoff.to/rsengines All these guys do is conversions. You can get ready to go engines or kits to convert your own and they have about the best prices.

Keep'm Off The Ground!!
Steve

Tmoth4

My Feedback: (1)

Carrprecision.com has conversion kits for Homelite 25 and 30 cc engines for about $40. You can also get the bigger and better carb for another $40. It increases the performance considerably. You have to cut away some of the flange on the crankcase and the fins off of the flywheel. The 33cc engine from the Homelite 14" chainsaw is also an excellent engine. It already has a better carb on it and takes less work to convert. The prop adapter made for the Ryobi 31cc fits on it. The 25 and 30cc from blowers and weedwhackers use a mounting plate on the back of the crankcase, whereas on the 33cc from the chainsaw you have to make up some sort of beam mount.

Jim

frequent flyer

My Feedback: (6)

Does anybody make conversion parts for the homlite 45cc off the timberland chainsaw? I saw one today at Home Depot, it had alot more compression that the 25cc they also had a 33cc. I never read about anybody using these, why not?

rsrogers

My Feedback: (10)

I have both the 33 & 45cc. The 33 in a H9 1/4 Cap & the 45 in a Texas Hurricane. If you do a search quiet a few others have them to. The performance of these engines are great for the price. The 45's have changed since I did mine. They have changed the carb mount to a flimsy rubber piece. The 33's are still the same (for now). You can get kits for them at RS Engines
http://takeoff.to/rsengines Subscribe to the news letter, the last one shows detail pics of the changes on the 45cc

Keep'm Off The Ground!!
Steve

Tmoth4

My Feedback: (1)

I converted a 33cc out of the Homelite 14" chainsaw. It runs great.