Small engines big hassle

[Piers Bowlan]

Erm... Why?

[Engine Doctor]

Posted by bert baker on 13/10/2017 10:44:10:

I may have a go at converting a head to standard plug

you will need an old cylinder/barrel to screw the head into to hold it while tapping thread for normal glow plug and to protect the fine thread for the head to barrel joint .A lathe really does come in handy for this.

[bert baker]

I have today had a go at getting them all to run,

The one that has front induction works but wont peak out, but is sporting a bigger prop than the others

The other two,

Well i held both nose down and put a little fuel on the air filter mesh on both and turned the prop and both pulled the fuel in and didn't try to squirt it back out.

I then primed them and both ran for a longer time than just priming through the port,

I have rechecked the fuel needle and its seat in the tank,

I am suspecting the spring that is fitted to the fuel pick up pipe,

I have removed it cleaned out with a pin and refitted it.

[brokenenglish]

Bert, I think Piers asked why I thought these reed valve engines are not worth messing with. Well, they're unpredictable and it's difficult to achieve consistent runs. There's very little flexibility, no real idle or slow running possibility. Even if they're "set rich", they still scream when the fuel runs out. Honestly, their only virtue is that they're cheap!

Could I offer this video, as a "Small engine - No hassle". Have a look, and then reconsider whether it's worth messing with a reed valve 049.

https://www.youtube.com/watch?v=0FwT5pKOHgw

 

 

Edited By brokenenglish on 13/10/2017 21:27:17

[Piers Bowlan]

Ah OK, I understand now! The 049 reed valve engines have two throttle settings, 'screaming' and stop, they just don't do idle or slow running. They were made for the C/L and FF era, climb and glide type of flying. If you want an RC throttle fit the Paw 100 in the vid (very nice) or OS 10 or 15 glow, depending on whether you prefer the smell of burnt ether or nitro in the morning. If you like neither, go electric!

[Bob Cotsford]

IIRC they did a 'throttle' for the .049 reed valve jobs but I think it was an exhaust strangler - for some reason they didn't catch on . As Piers said, they were great for c/l, ff or single channel where they were pretty reliable. 2-3 minutes of full power was often more than long enough.

[Peter Christy]

Posted by Bob Cotsford on 17/10/2017 15:16:09:

IIRC they did a 'throttle' for the .049 reed valve jobs but I think it was an exhaust strangler - for some reason they didn't catch on . As Piers said, they were great for c/l, ff or single channel where they were pretty reliable. 2-3 minutes of full power was often more than long enough.

I still fly a pair of single-channel models with .049s, and yes, 3 mins of full chat is more than enough!

There was a "proper" carb made for Cox's by Tarno. I actually have an unused Tarno carb somewhere in my junk boxes. I believe they didn't work very well without a muffler to provide some back pressure. The basic carb is designed to screw into the inlet of a TeeDee, but I've also got an adapter to make it a rear mount for a reed valve engine with an external tank. I must confess that I've been thinking of building a tiny "full-house" Cox powered aerobat for a while, but other projects always seem to get in the way.....

A note to the OP: Cox's do NOT like being over-propped! They like to scream! You wouldn't try and pull a Ferrari away from rest in 2nd or 3rd gear, and similarly, don't expect a Cox to run properly with a large prop!

--

Pete

[bert baker]

My little AE 0.5cc runs nice,why can't the Cox do the same

[ted hughes]

Cox International usually have a lot of spares:**LINK**

[Peter Christy]

Posted by bert baker on 17/10/2017 18:51:30:

My little AE 0.5cc runs nice,why can't the Cox do the same

Diesels are usually quite happy swinging bigger props. Cox engines like to rev! Small props and lots of nitro are usually the answer!

--

Pete

[ted hughes]

Posted by brokenenglish on 12/10/2017 20:32:55:

Posted by Piers Bowlan on 12/10/2017 19:51:54:

Did somebody actually buy the $90 Black Widow?

Not yet Piers. It's still on sale at the moment.

With the selling format adopted, I think the guy will leave it on sale for a week or two, and then let it go for the best offer he receives, but we won't have any way of knowing what the actual sale price was ...

You can do an advanced search for sold items to see what items go for. A NIB Black Widow goes for about £35-£45.

[brokenenglish]

Ted, I think that's only true in the case of an auction or a simple BIN.

If an item is listed as BIN or offer, which was the case here, and the seller accepts an offer, then the amount of the accepted offer won't be shown in the finished listing and, as I mentioned, there is no way of knowing what the actual sale price was.

.