That's great!

After I read your post above, I sent an email to Lawnstation asking how much a bare short block would be. I was told $109. I wonder why that is... Apparently, it cost the same with or without all the trimmings (carb, flywheel, ignition, etc.)

Just finished tearing it down...some junk to get rid of, all the plastic on the carb filter etc...fly wheel ...talked to C&H a few ago...

It's not a new motor...(Okay, I'll say reconditioned) and has been into....no scores on the piston or liner...has carbon on the piston and the plug...but comes with a 30 day guarantee, we'll see...

What are you using for the beam mounts??

Michael

I bought one last fall from them to cut some trees with. When I'm done it will get converted as well. It has ran flawlessly for me so far! Guess I'll have to get the rest of the trees cut so I can get started on it! That is unless the Tecumseh 49cc turns out well.

Oil mix???
And what oil, If you wouldn't care to share..

The Poulan saw, 40:1 high quality 2 stroke oil for aircooled engines. Airplane engines that are well broken in, 64:1 Amsoil.

Looking at airplane specific manufactured engines compared to the Poulan46 the poulan has a lot more cooling fins. Presumably because it was to be encased with little airflow. So why not remove some of the lower fins and decrease the size of the upper ones a little to save weight? It would the more so resemble an airplane engine. Unless of course a guy wants to use it with minimal cooling holes in the cowl for appearence reasons.

I believe on rcfaq they did just that to one of their 46s. Looked pretty good.

other than cosmetics it really does not save but a single oz.

Darin

Gentlemen, I also have purchased the powerhead from Lawnstation. I currently have it all stripped out of chainsaw parts and ready for conversion. I also removed all the return springs on the choke and throttle lever mechanisms. This leads me to a question, there still seemed to be a small amount of spring tension on the throttle butterfly. Upon disassembly I found that there is a small spring loaded brass plunger with a o-ring that is actuated by the brass butterfly valve control rod. I am concerned about the throttle servo having to over come this spring tension while flying, putting unnecessary load on the servo. Does anyone know what this plunger does? It seems to come into play when the throttle is reduced to idle. My engine was one of the pro series if that helps. Any help is appreciated.

Thanks,

Maximus

It's an accelerator pump..If you take it out there will be an air leak in the carb, so leave it in..There is not enough resistance to the rotation to make any difference on the servo load...
The one pictured on rcfaq was mine, it just looks better that way....

Ralph, is that accelerator pump on every Walbro carb? I've detached the spring on several of them, but didn't notice any problem. Then again, I could've had a problem and just not know it.

As for reducing the fins, I agree it's more a cosmetic thing more than anything. I did that on a Ryobi 31cc way back when. Thinned every one of the fins and shave off the front and corners, all by hand. Ended up saving less than 1 Oz. Hardly worth all the work I spent on it. If you have machine tools that can do this efficiently, that might be a different story. Otherwise, cutting the fins is only worth doing if it will help the engine fit in the aircraft better.

Still, if you are willing to spend the time, and cut the fins as part of an grand scheme to reduce weight, then the overall result might just be worthwhile. For example:

1. Cutting off the rear shaft on some engines
2. Shaving off unecessary webbing, appendages and bosses
3. Fluting and/or coring the prop hub, flywheel, and other rotating parts.

An Oz here, an Oz there, might add up to a significant amount.

Most Walbros have no pump...There are two types of pump, the one with the plunger and another that uses some cross drilled holes in the carb shaft and body...Not necessary on our airplane engines.....

Thanks RCIGN1, I'll leave it in!

Maximus

sorry... meant to put this in a PM

The Mustang 50 and the Fuji 50 from Tower are half brothers.

Enjoy,

Jim