Zeetah

The engine runs great, starts easily but seven times out of ten, it will start backwards.

To get it going the right way (counter clockwise), I have to stop it (by grabbing the spinner - there has to be a safer way) and then retry.

The piston and con rod are just a tad loose. Could that be it ?

Do I need to reduce the compression ? I already have two glow head shims.

What else can cause this ?

Thanks.

Tim Wiltse-RCU

Is this a Cox reed valve engine and are you trying to start it by hand flipping?


Later,
Tim

3 Channel Brain

All reed valve & or piston port 2 strokes will run either way.
I have seen people starting up by flipping clockwise. an electric starter will also force it to start up CCW. Norvel sells one especially for small engines. pinching the fuel line or pulling it off
is prolly a safer way to stop bad starts.

Zeetah

This is a Black Widow - reed valve engine.

BMatthews

You can try flipping it backwards. If your odds hold true it'll start the right way 7 out of 10 times. But just as in Vegas there's no such thing as even money....

My suggestion is to get one of the Cox starter springs. These almost guarantee easy starts and ensure the prop is going in the right direction.

And go back to the single head gasket. If the rod socket is loose it's wise to have it reset since it'll only get worse with all the banging around it's doing.

Zeetah

The engine likes to run backwards - when I have flipped it backwards (clockwise), most of the time, it will run backwards (clockwise).

It is pretty annoying...

Rick Lindsey

Have you considered mounting a pusher-prop and just letting it run backwards?

Bipe Flyer

I've had the odd COX that can't decide which way to run and it just flips 1/2 a revolution back and forth.

matchlessaero

Zeetah, I saw some cl Mouse racer pit men use this trick.

They sawed off a 1/4" hardwood dowel to about 5" long. Over the dowel, they slipped some clear 'hard' plastic tubing like you can get at any hardware store. They left a portion of it open over the end of the dowel (about 1/2").

They would then use the dowel as a chicken stick in the normal manner to start the engine, and in the event they got a backwards run, they would poke the open tubing end over the spinner. This was just enough friction to stop the engine.

I noticed Lynn S was using a similar 'tool' while starting his starter spring equipped Black Widows. (good idea...)

Gollywock

I've always kept a cloth rag in my back pocket and whenever an engine starts backwards, I simply toss it into the spinning prop, then, restart. Jim

Tim Wiltse-RCU

Zeetah,


Get your hands on a Cox Zero Drag starter spring like the one I have on my engine in the picture. It diengages from the prop and does not use the cam like other Cox springs. Sorry for the bad photo.

Later,
Tim

P.S. Hey Bipe Flyer... your flippy engine is over compressed get another head gasket on it!!!