marwen1

My Feedback: (6)

I HAVE A SMALL .049 COX GENERIC ENGINE WITH A SMALL TANK ATTACHED ON THE BACK.

IT WILL FIRE UP WITH A POWER PANEL AND THE CONNECTOR CLIPPED TO THE GLOW PLUG.

RPM'S CHANGE OK WITH THE ADJUSTMENT OF THE NEEDLE VALVE BUT THE MOMENT I TAKE THE CLIP OFF THE PLUG - IT QUITS

SUGGESTIONS PLEASE

marwen1

ArcticCatRider

My Feedback: (6)

Lean it out! If it's quitting when you take the heat off, it's too rich. Too much fuel is hitting the coil, taking the needed heat away.

MinnFlyer

My Feedback: (4)

Or it could be a bad glow head.

ArcticCatRider

My Feedback: (6)

Definetly. But best start with the easy, "free" changes before you start replacing things/taking them apart

C185Pilot

My Feedback: (25)

Make sure that you have FRESH (that means newly opened) fuel.

Lamoilleriver

Use 1/2a fuel, not your normal 5/10/15% nitro fuel will help.

marwen1

My Feedback: (6)

New Plugs - I think I have about a doz. or more.

I thought I spotted a drop of humidity in the syringe.

In fact, I think this fuel is over 1.5 years old. The container I had it in was plugged tight... I'll try to lean it out... If that don't work

a new Qt of - what ??? 25% nitro

marwen1

jetpack

My Feedback: (1)

20% castor oil is best, between 10% and 30% nitro.

jaka

Hi!
...And a 5x3 or 6x3 prop (if it's a .0.049 engine).

C185Pilot

My Feedback: (25)

Fuel at 1.5 years is not fresh especially if it is in a plastic jug. Believe it or not water molecules will permeate the plastic and foul the fuel. I agree on the 20% castor and 25-30% nitro.

jetpack

My Feedback: (1)

Cox engines are chrome piston steel sleeve motors, best to use castor for good sealing and also the ball and socket wrist joint. They starve a bit under the piston and it is good to have all castor there. It is one of the hotest parts of the engine and still has to move.

If you are leaning out your motor to get it to run with a new plug, and your using normal (synthetic oil) model fuel, you might run into wear problems. Two ounces of castor to a normal gal of synth blend should be fine. It will also slightly raise your compression so maybe add a head shim too.

Sport_Pilot

If you are not using at least 20% nitro with all castor they engine will not run right.  They are set up for about 25% nitro and 20 to 25% castor oil.  The plug will be to cold for lower nitro, and the compression will be poor without a lot of castor oil.

marwen1

My Feedback: (6)

That some good input.

Those dozen plugs that I have are a mix of standard as well as High Compression.

I'll have to get some shims at the LHS

thanks again

marwen1

downunder

I'd never run any Cox engines until my son gave me quite a few of them so I thought I'd give them a try with my usual 80/20 castor fuel. All of them, from a Babe Bee to a Tee Dee .049, gave me one flick starts (I didn't bother with the spring starter) and they all ran beautifully. Sure, they'll give more revs with nitro but they certainly don't need to it to run perfectly. Is this another myth busted?

jetpack

My Feedback: (1)

Adding one or two shims on this size engine has a noticable effect you'll see it in ease of starting and lower power output. Going past three shims you won't see much power but it will still run and start fine. See how it does with three shims to start with, then experiment and start taking one shim out at a time until you have good luck with both starting and the amount of power you see. I always remembered to run two shims with a TeeDee/head. One shim always seemed to want to overheat the engine.

Before the only way to buy Cox head shims was to buy a glow head but I see now that Cox sells them seperate. Also be sure you know how many shims are in your cylinder to start with. I have seen shims in the top of used engines that you swear weren't in there, they tend to hide.

marwen1

My Feedback: (6)

YEP!! YEP!! YEP!! Amazing what one can do with fresh fuel.

Fresh fill up, one flip of the spring and VOILA - I barely had to tweak the RPM's and it went up to 18K or better.

With a little effort I can probably get it up another 10% or better.

All I want to do is to get my GENTLE LADY - 2 METER - SAILPLANE up within a couple of weeks.

marwen1

marwen1

My Feedback: (6)

The fuel I got from the LHS was 20%/16% caster. I was wrong with that RPM more like 14500K

I have a short tri blade on it. - I assume that the small tank is a .5 oz - no shim With a full tank running wide open, I'm only getting 30-35 seconds

How can I increase my time?

marwen1

Sport_Pilot

The will run that way, but at about half power (or so it seems). The plug is just too cold for low nitro.

marwen1

My Feedback: (6)

QUIRKEY LITTLE THINGS - AREN'T THEY?

If I change to a somewhat normal plug - will that help?

marwen1

Mr Cox

There is actually nothing particularly quirkey about them, just like any other glow engine they just need the correct fuel and prop. 20% all castor fuel with 10-20% nitro and a 5x3-6x3 prop.

The heads that take regular glow plugs are down on power unless you seal the threads and rework the head to get the correct compression ratio. You can get original plugs from coxengines.ca or the new replacement plugs from Merlin.

marwen1

My Feedback: (6)

I guess the only reason I am using a 20% NM/ 16% Oil is - that is all my LHS had to offer at the time I bought it.

I am using a 5/3 Pusher Prop. In fact I took the spring off so that I wouldn't loose that extra 500 RPM (or so)

"Querkey" was simply a figure of speech!

I find it so bloody hard to "say" something while writing without upsetting someone's applecart.

Y'all have a great Mother's Day!

Gotta go. It's time I got out and went to my flying field and gave the boys a hand cleaning it up after our unusually large snowfall this past year

They don't call this place WINTERPEG for nothing.

marwen1