I am in the process of converting a 22cc Echo engine, which has a Left Hand thread for what will be the prop hub. I am a little concerned about the thing wanting to come loose when running. I know they are popular conversion engines, so is their a fix, or just not to worry, tighten the thing to the max and use threadlocker?

Thanks, flyrc

Any engine I have done has a right hand thread. The clutch side of the crankshaft has a left hand thread but you cut that end off near the bearing. The end you want to use is the end the flywheel was on and it should have a taper on it too. I have bored the taper on some and I have just bored straight on others. Either way use Loctite. I use green Loctite number 620 I believe. Never had one come loose.

The problem with putting the hub on the flywheel side is engine rotation. The prop will spin backwards!
The pull start is on the flywheel side and I confirmed rotation before taking it apart. I guess alot of torque and Threadlocker is what Im back to.

Hi,
If ha a plastic flywheel, you may be able to reverse it to get correct rotation.

Dave

What engine is this? I am sure some spin clockwise but all mine run counter clockwise. That being said as the engine is running the crankshaft will want to tighten the hub to the crank.

All of my little ECHO's have right hand threads on the flywheel end and run ccw from the flywheel side.

Hi,
I have an Echo 21 from a Mantis tiller that had the flywheel spining clockwise and the clutch and drive shaft coming out the back that we use for a mount. The flywheel is on a shoulder with a flat to secure it. Also many Echo blower engines run clockwise driving the impeller with the other end.

Dave

Why couldn't you turn the crank around? Wouldn't that solve the problem? Besides that the ones I have done have a pretty course thread on the clutch side of the shaft as I recall.

Well, I must have a rarity, the engine is a Kioritz "F-2", and yes the aluminum flywheel spins clockwise . Furthermore, the threads are LH on each end of the crank! If anyone wants a counter rotating mill, this is it!

Hi Tim,
Turning the crank is a good idea, but the flywheel wouldn't fit. I was going to suggest that, until I realized the flywheel issue. It would be a great solution for EI. I found a twin peddle reed assembly for $12. http://scooterpart.net/partpage/47cc...ed%20Block.htm

Dave

Just FYI Kioritz is or was part of Echo in the old days. Now it is just Echo. How about a picture or two of this little beast?

Dave that part looks darn near like what the stock ones do. Thanks for the link!

Tim

Why not try to run it GAS/GLOW fuel mix? The flywheel and magneto would not be needed and a glow plug plus glow adapter substituted
for the sparkplug.

Heres a picture of the little devil, it looks just like a redmax except the rotation is reversed:

Someone building a twin would like to have a counter-rotating engine.

Bill

Yes sir that thing is different looking. I have 4 twin Echos here and they spin CCW.

Either way I still have a LH thread on both sides of the crank. I could make a prop hub that bolts directly onto the flywheel, that takes care of the LH thread problem, but it would be a counter-rotater. Anybody got a twin project in need of a G23 sized CCW mill?

You absolutely do not want to try to run left hand threads. The engine pulses act like a hammer wrench and will loosen the nut every time. I think it was MikenLapaz that posted some scary experiences with this here in the forum.

AV8TOR

Hi,
This would make a dandy engine for a pusher design. With the engine turned around, using standard props everything will work fine. The prop selection is unlimited and the lefthand stud will be tigthened durning operation. You will have to use an electric starter or get used to flipping backwards. Getting the 12" separation from the radio equipment may be an issue.

Dave