Pee Wee 020 engine running erratically

sosam117 Tue Nov 17, 2020 12:01 am

A friend called today and asked if I did a little work on his plane, he'd give me an engine.
O.K.
Made the wedge for his motor mount (down thrust and side thrust).
Soldered up his landing gear wire.
Made some copper shims to reduce end play on a worn engine.

He gave me (almost new) Pee Wee 020.
He said he was having problems with inconsistent running and it was mine after all the work I did for him today.
Well after he (Jack) left, I started to take the engine apart to see what the problem could be?
I didn't have to go far. It was a messed up needle valve.
I don't know who did it or how but what the Devil

I still tore the engine down to inspect all of the parts for any problems. It seems it's just the needle valve.

How could this have happened? confused

Pee Wee 020 engine running erratically Pee_we10

Well. It looks like I'll have to get a replacement needle valve.

KariFS Tue Nov 17, 2020 1:43 am

I have seen some needle valves with a bent tip, and a few that have bent from the other end because of hard landings or getting knocked around in a box, but that is something else.

Maybe at some time a needle tip was broken off and stuck in the valve, and this one installed without getting the broken piece off first? Hopefully the threads on the backplate are OK.

Congrats on the ”free” almost-new Pee Wee!

706jim Tue Nov 17, 2020 8:06 pm

KariFS wrote:I have seen some needle valves with a bent tip, and a few that have bent from the other end because of hard landings or getting knocked around in a box, but that is something else.

Maybe at some time a needle tip was broken off and stuck in the valve, and this one installed without getting the broken piece off first? Hopefully the threads on the backplate are OK.

Congrats on the ”free” almost-new Pee Wee!

That seems like a logical explanation for the bent needle. Probably better than the tip of the needle broken off and jammed in the seat.

"Close needle valve and open 2 1/2 turns". From the factory instructions. Not a good idea IMO.

**Cribbs74** Tue Nov 17, 2020 8:31 pm

What Kari mentioned were my thoughts exactly. I would make a careful inspection before installing a new one.

sosam117 Wed Nov 18, 2020 12:53 pm

Cribbs74 wrote:What Kari mentioned were my thoughts exactly. I would make a careful inspection before installing a new one.

Yes, I think I'll use a small wire and poke it through the needle valve hole to see if there is no problem when it pokes out at the venturi hole.

After typing the above reply, I went out in the shop and used a .016 into the needle valve hole.
Yes, there is something in the hole? The wire didn't reach the venturi hole.
I bent the .016 wire (90deg.) and pushed the wire into the venturi side of the needle valve hole.
After a while of trying to push the wire in the venturi side, something popped out the top of the needle valve hole.
It dropped onto the white shop towel (paper).
A close inspection reveled that it was a small chip of metal (maybe from manufacturing?)

Well, the hole is now clear and I can see the light from the flashlight shining through the tiny hole (from the venturi hole).

Thanks all! I Love This Forum!

706jim Wed Nov 18, 2020 1:56 pm

Either a new a metal chip or possibly the broken off end of the needle valve. If you inspect a new Pee Wee needle valve you will see that the end is REALLY tiny and fragile.

sosam117 Wed Nov 18, 2020 11:30 pm

706jim wrote:Either a new a metal chip or possibly the broken off end of the needle valve. If you inspect a new Pee Wee needle valve you will see that the end is REALLY tiny and fragile.

When I got this engine from my friend, he said it was running erratically.
So, I removed the "original" needle valve and discovered it bent.
The piece of metal is not from a replacement needle valve but a machining chip.

Here is the photo of the original needle valve. The tiny end is still there at the end of the NV.

Pee Wee 020 engine running erratically Pee_we12

Oldenginerod Thu Nov 19, 2020 4:58 am

I would have thought that to compress the needle like that it would have to be cranked down against the "chip" pretty hard. In turn, that would have embedded the chip pretty firmly into the hole, so I'm surprised that the chip popped out relatively easily with a small right angled wire. I thinks there's still something else going on, but we may never know. If the holes are clear, the needle is replaced and the engine runs ok, I guess it doesn't matter, but it does raise the curiosity level.

sosam117 Thu Nov 19, 2020 6:10 am

Oldenginerod wrote:I would have thought that to compress the needle like that it would have to be cranked down against the "chip" pretty hard. In turn, that would have embedded the chip pretty firmly into the hole, so I'm surprised that the chip popped out relatively easily with a small right angled wire. I thinks there's still something else going on, but we may never know. If the holes are clear, the needle is replaced and the engine runs ok, I guess it doesn't matter, but it does raise the curiosity level.

That chip didn't pop out that easy.
I also was using very small needle nose pliers on the wire and it took about 1/2hour until the wire went farther in.
I was thinking of using a #77 drill and clear out the blockage where the needle valve threads in.
Luck would have it, that it did become dislodged with the wire.

Iceberg Thu Nov 19, 2020 10:32 pm

Hi Friends
I have what should be a very simple question. A good friend sent me this motor the other day. It was gummed bad. I cleaned it well. Put hose on the NV with a washer and reassembled. It has a plastic tank, plastic backplate and has a sure start cylinder. I believe all original.

What and when was this motor sold as. It almost starts to look like a Texaco but not so am curious. I'll put the picture to see.

Sorry for elementary question.
Thanks
Ice

Pee Wee 020 engine running erratically Img_8010

balogh Thu Nov 19, 2020 10:40 pm

I think the tank and backplate are those sold by Bernie and Matt so the engine is likely not a stock but home assembled.

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