Four stroke float planes
 

Hello; I went down to our lake today, there were 8 planes there altogether, only one had a two stroke in it. There was only one crash, a nice Beaver touched a wing tip on take off then cartwheeled in. One fellow had a BTE Flying King with flaps, great flyer, it looked like a lot of fun to fly slowly. The only two stroke was on a LT 25 trainer the pilot pretty much kept it at full throttle the whole time, while all the other fellows used the throttle throughout the flight. One fellow had an OS 70 on ignition in a goldberg cub. Most flights were pretty scale with the odd loop thrown in.

I don't have any two strokes anymore, and haven't for nearly ten years now, and I notice that it's a rare occasion to see a two stroke anymore. The dedicated scale flyers use four strokes exclusively. I doubt that I influenced this four strokism, but these guys have been modelling for nearly 40 years each. Is it a general trend away from two strokes?

RE: Four stroke float planes
 

I think it's a personal pref. I prefer 4-strokes on any plane 60 size and above, of course, I don't fly extreme speed planes either.

As far as seaplanes go, I use a 4s on my goldberg cub, because I fly it on land with a 4s,

As for other planes, (Seamaster, Mariner, etc) I prefer 2 strokes only because I don't want to run the risk of ruining a good 4s by dunking it (Or worse, having it sink!)

My dad, on the other hand uses nothing but 4s in everything including seaplanes.

RE: Four stroke float planes
 

I have flown a 4-stroke telemaster for several years. OS.91 on a Senior TM. It flies like a dream.
One thing, tho: The bearing cavity, & crankcase is not purged with a 4-stroke like it is with a 2-stroke. When you dunk a hot 4-stroke, the chill causes the air in the crankcase to contract, which sucks water into the crankcase vent. It tends to stay there. The bearings, crank, cam, and tappets will all rust. I let mine set up several weeks, and it was locked solid. A buddy's ENYA did the same thing.

Suggest you regularly flush the crank vent with a corrosion inhibiting oil. Corrosion-X is my choice, but Marvel Air Tool Oil is pretty good, too. Stainless Bearings from Boca are good, but the other parts are still steel and they will rust.

RE: Four stroke float planes
 

Jim
I noticed that also. I had a lazy bee about 5/8 through a loop before I ran out of air and dunked the Magnum 30fs. I ran it again and oiled it but the thing still rusted. That water stays in the case.
Ben

RE: Four stroke float planes
 

Personally, I think a 4 stroke is just more "pleasant" in the types of places we would tend to fly float planes.

I know myself, I'll be flying off a beautiful mountain lake, with fellow cottagers all around. This environment is much more sensitive to objectionable noises than a regular flying field in the middle of farmland. Most people find 2C engines more objectionable than 4C engines, both in tone, and volume.

Motorcycle and Snowmobile riders are learning a hard lesson that all those years of running open pipes... might not have been such a hot idea. There's a whole lot of momentum going to ban these vehicles from just about all wild areas.

If we want to continue to have the freedom to fly in areas like this (as I'm sure many of us do), then it's best to use 4C that aren't as annoying to others in earshot.

RE: Four stroke float planes
 

Some members in my club shy away from four strokes in certain planes. A laker is one, the engine is mounted on a pod, and a four stroke will vibrate it more than a two stroke. Profile planes are also sensitive to four strokes. Some planes it works better one way than the other.

RE: Four stroke float planes
 

I definitely love my 4-stroke, and the torque is really handy in a slow-moving floater like my Telemaster. My comments were more in the "Proper care and feeding of the 4-stroke" category. Most of my flying is at less than half-throttle, and it makes a pleasant burble-not a 2-stroke whine. Big prop, low revs, happy face.

RE: Four stroke float planes
 

Of my four water airplanes I have right now only one is a four stroke, a 105" old time Quaker. The engine on it is a Saito .56 that has hundreds of flights on it, all on the Quaker and has been dunked many times, as on the 2 strokes all I do is flip the plane up right, prime the crap out of it and start it, get in the air ASAP and keep flying. NEVER PUT IT AWAY AFTER A DUNKING. Flying the airplane again heats it up and gets all the water out while lubing it with the oil in the fuel. I only us Power Master 10%, 100% synthetic oil....

RE: Four stroke float planes
 

A couple other pics...

RE: Four stroke float planes
 

From experience I would sugest that 2c's are almost impervious to water. Just flush them out and oil them up and they are good to go.
Even racing boats with regular dunkings I didn't suffer any damage from water.