helicool

My Feedback: (6)

I just picked up a Poulan 2900 46cc for $50 today slightly used. I think they might have cut 1 tree with it. I've stripped it down and I need to know a few things.

Who makes a prop hub for this engine?
What about a carb adapter? I noticed its the slip on kind.
Should I cut the shaft with the funky spiral cut gear on it off?
Is the case Magnesium or aluminium? Dont need a fire I cant put out! :spinnyeye

Thanks!

helicool

My Feedback: (6)

Does anyone make a pitts muffler for it?

Antique

My Feedback: (4)

Cut the shaft a little longer than the seal, the case is Aluminum, C&H makes a kit for the carb and hub..............

helicool

My Feedback: (6)

So, I can basically just cut and trim at will on the whole motor then? Im putting this in a SIG Extra 300XS and want to minimize the weight. I will end up putting electronic ignition on it when I get some extra money.

What prop size should I start out with on this?

Wayne H

This is a scratch built Senior Kadet with 85 inch wingspan and a 21cc Echo conversion. Flies great. I have done a couple of Homlite 25cc's and I buy all my conversion parts from Dave Carr at www.carrprecison.com.

lynngordon

Rich, a 20x10 would be about right. Using those on my Sig Extra 300XS ARF with an FPE 2.4 (40cc).

Lynn

Wayne H

oops....here's the pic

Volfy

My Feedback: (23)

Wayne, nice engine/plane combo. How does your Echo 21cc run? What rpm and prop? I can't quite tell from the photo if you used the magneto ignition or not. I'm really liking these Echos for small displacement weedies. If you're willing to spend some time trimming the crankcase and fins, they come out really light and work great as replacements for 1.20 size glow engines. For anything larger than 35cc though, I prefer the Poulans.

Wayne H

I am running this engine with the magneto. The flywheel is plastic so it is not much lighter with electronic ignition. It turns a 16x8 prop pretty good. I don't have a tach. I am using the stock carb and muffler with the spark screen removed. I am very happy with this engine. As you know, Echo is a top brand and I expect this engine to last a very long time. I know this engine is ringed but I am unsure if it is two or one. There is always a fellow at the club that helps out with holding the plane when starting and they are always suprised when I start this engine up just barely ticking over in idle. A very smooth running engine.

Wings-RCU

My Feedback: (2)

Volfy,
Don't be surprised if your RPM's drop with the LOWER altitude. Your performance (climb) should go up, but RPM & airspeed should go down at lower altitudes.

jwv3

My Feedback: (1)

Sorry to get off the subject, but how much did you have to modify to handle the gas engine? Would it be possible to start with the Kadet kit and make changes or is scratch building it the better way?

Wayne H

The only parts of this plane that actually came from the Senior Kadet kit is the wing ribs. I ordered the wing kit from Sig not the whole Kadet kit. I used 1/8" Luan plywood for the fuselage and I used clear doug fir for the spars. The original Senior Kadet kit could be beefed up and used but IMO it is stronger to build the fuselage with the plywood. The kit builds really light. If you use the stick method, you would probably want to increase the stick size from 1/4" to 3/8" balsa sticks and use plenty of gussets.

captinjohn

Whyne H: What model no is the Echo engine...can you post a close up photo of it? Thanks Captin

Volfy

My Feedback: (23)

Yes, I've been noticing that to a certain degree. The rpms tend to vary with humidity and ambient temp too. 100% RE at 95F definitely does not power make.

I think you're refering to the fact that the denser air down here at sea level also means that the same prop will have to turn a higher load too, which may actually offset any gains the engine might get from more oxygen. I think that may very well be true.

jwv3

My Feedback: (1)

Hey captin, there are quite a few Echo tools that use the 21.2cc engine. I have one from an HC-1500 hedge trimmer and I know the SRM-2100 line trimmer uses it also. Check out http://www.echo-usa.com/start.asp , they list all engine sizes.

jwv3

My Feedback: (1)

Thanks for the info.

Bernett

Wayne H

How do the Echo 21cc engines compare with the Homelite 25cc engines? I may have an opportunity to buy one cheap, but don't want an undrepowerd engine. I heard that Echos turn a higher rpm.

Thanks

Paul

bdtsr

My Feedback: (5)

Alright, I must confess. I don't even have my Ryobi done yet and I bought a Tecumseh 49er for another conversion project with the possibility of a Tecumseh 139cc big block next! I am picking up a used GSP Edge 540 as a test bed for my bigger conversions. Anybody know the average time until you're cured of the conversion addiction? I'm not really an addict, I'm in complete control and can stop at any time! he he he!

Wayne H

Bern-
If you want the most power out of these converted engines, your going to have to change the carb. I think weed-eater's are set up so that the rpm is limited so that the string does not disinigrate so easily. I have the stock carb on my Kadet and it flies it just great, plenty of power for this high wing plane. I don't think this would work well on a low winger. My Homelite 25cc has a larger carb on it and it spins a 18X8 prop pretty good.

james04

Were can I find a how to on engine conversions? What is the cheapest source for new engines to be converted(make/model)? Do you really save money in the long run over buying say a ZDZ 40 or Zenoa? Oh and a source for the conversion parts. Thanks in advance.

James

captinjohn

James04: Do a search...type in what subject or engine you want data on. www.lawnstation.com has engines ....... just start reading....its all there...anything you want to know ..... Good going Capt,n

Volfy

My Feedback: (23)

James, conversions can be cheaper, especially if you reuse the magneto ignition that came with the weedie or chainsaw. If you go with an electronic ignition, you may end up paying almost as much as a made-for-RC gasser engine. However, you will likely save money in the long run because you can always reuse the ignition parts if the engine goes kaputt. Replacement engines cost anywhere from $0 to $150 (for up to 50cc). There is typically next to machining work required for an elec. ignition, so replacing a worn or damage engine block is pretty much a direct bolt-on.

Best engine sources are Lawnstation, Ebay and your local lawn care equipment service shop. Being patient in your search will net you great bargains.

captinjohn

Volfy: The more I re-think this. I believe a poulan 46cc with stock ignition is a good engine, that does not weigh too much. I think instead of going out and buying a electronic ignition....more thought should be put in getting the right plane and setting it up for tne 46cc poulan with its flywheel mag. The flywheel is good to have, as it absorbs power strokes and smooths out the engine. Most flywheels on engines are meant to do just that...make it smoother. It should be a simple to maintain setup without extra electronics to mess with and battiers to charge. Capt,n

bn120

My Feedback: (1)

that is exactly why I left it a mag on my cap, between the small mag and electronic ign. they weight within 4 oz. of each other by the time you weigh the switch battery and ign,however on my stihl and husky engines the flywheel is so big and heavy that the electronic ign. cuts alot off weight.

Darin

captinjohn

Of all the chain saws I have owned...the Echo is a real rip-snorter in the 30cc size. It runs so good and cuts so good I hate to chop it up to make a airplane engine. I bet it sure would make a good RC engine. Has anyone converted a small Echo saw...would like to hear comments. Thanks Capt,n