flipflop

Ok guys, for this project I wanted a lightweight, magneto motor. So a quick trip to Home Depot got me a new GT 200-R weedeater. Straight out of the trimmer it weighed 2lb 15oz. With the stock carb and muffler on the brand new motor the Bambula 16x8 turned 6990rpm. Started easily by hand, looking good so far.

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Trimming the stock flywheel only saved around 20 grams but combine that with a new homemade muffler and losing all the excess crankcase casting got the current weight down to 2lbs 11oz.

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You can tell that Echo wasn't trying for max horsepower here by looking at the stock base gasket. Easy to fix.

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Now it's time for BMEs "Don't forget Echo" mods. I took .015 off the base of the cylinder, took the exhaust timing back up to 154* and changed the intake to open a 110* ABDC. Stock exhaust timing is a HP killing 120*. Yeah, I know, after looking at the photo of my exhaust porting I had to go back and polish it and slick everything up.

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Now, after the mods with the homemade muffler the same Bambula 16x8 is spinning at 7670rpm. Made a new carb adapter, that and a 11mm Walbro got the rpm up to 8020rpm. Just tried a MA 16x6 and it turned 8280rpm. All up weight now is 2lbs. 9oz. Not too bad for 21cc. I still need to stick that tuned pipe on it sometime though It starts very easily by hand, haven't used an electric starter on it yet!

tim220225

My Feedback: (4)

Flipflop, how did you make the muffler? Any pictures of the internals and what material did you use?

Frank B.

My Feedback: (1)

Nice work, thats one thing you dont read much about here are port timing mods.

Did you measure the transfer ports by chance? and what the squish clearance was before you removed the .015 off the cylinder.

That flywheel look like its made of a composite material, correct?

Thanks
Frank B.

Wufnu

My Feedback: (2)

Not to derail but I notice all of the Echo engines have a slanted plug. Mine has a top plug and it's the only one I've seen so far like that? Just curious.

You're doing a real professionl job! It's obvious that you know alot more about conversions than I do, why aren't you trying gas/glow mix? I'm sure you have a reason, that's why I'm asking (that is, I don't mean it in a "what's wrong with you, why aren't you blah blah blah" sort of way). Thanks!

captinjohn

Maybe some Echo Guru could post which engines have in line with bore or slanted spark plugs!! Thanks Capt,n

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The muffler is machined from 2" barstock. The main body bolts on with two short 5mm. capscrews. The muffler cap bolts on with three 4mm. capscrews. The body is tapped for the 3/4 in exhaust tube. Got the 3/4 tap and die and 8 feet of aluminum tubing at the local True Value hardware store for about the same price I'd have to pay for one "store bought" muffler. Sorry, I didn't take any pictures when I was making this. I've still got .032 deck clearance, so I could take another .015 off without having to do any cutting on the piston (no, I didn't make as radical mods as Keith did since I was planning on propping this motor to run around 8000rpm) The flywheel is made of thin steel plates (much like a Ryobi crank) and the plastic surrounding them is what holds the whole thing together. Glow??? Sorry, not me. Thirty years of running glow is enough. I went all gas a couple of years ago and will never go back.

aero nut

What about GAS/GLOW? it would end even lighter less than 2 lbs