Pioneer 1074 no idle possible

[Moondust]

Hello

after a long search on the internet i found this forum, so now i hope that someone can help me.

I've got a Pioneer 1074 chainsaw for more than 30 years and it was a lovely chainsaw, but about a year ago the love was over between us

It was not possible to let the chainsaw run idle.

Now i've started to cpr the saw.

This is what i've already done.
I rebuild the carburator (WA 22A) with a K10-WAT kit.
The parts with a blue circle i used in my rebuild.

I also put a new gasket between the carburator and tha white plastic part on the motor.

But now i still got the problem that i don't have the possibility to run on idle.

I start the saw with the choke closed and the throttle on half. This is no problem, i pull 2 times and the saw start but stops immediately.
I put the choke open and pull again and the saw starts and keeps running on half throttle. When i pull the throttle to the max the saw reacts immediately. So the idle needle is ok.

But when i release the throttle than the saw stops. The screw to set the throttle is also adjusted.
After the stop i just close the choke pull 2 times and the saw starts again.

So it's just that is is not possible to let the chainsaw run idle when i take a new block wood to cut.

Is there somebody who can help me get my lovely saw running again.

Best regards

 

[dougand3]

Welcome.
If the saw runs to Wide Open Throttle, you put the carb parts in correctly.
And you have adjusted Idle Screw (TAS, LA) ClockWise to where the chain barely doesn't spin? A little tick, tick, tick of the chain is good.
30 years- fuel pickup/filter and fuel line need replacement?

 

[2stroke_shaman]

The low circuit is plugged. Take out the low speed adjustment and follow the circuit back till you find the plugged hole . Might be under the welch plug. Common problem with old saws.

 

[Moondust]

And you have adjusted Idle Screw (TAS, LA) ClockWise to where the chain barely doesn't spin? A little tick, tick, tick of the chain is good.
30 years- fuel pickup/filter and fuel line need replacement?

Hello

I have set the Idle Needle 1 and 1/4 turns open and than started to turn clockwise until when i pull the throttle full open and the saw reacts immediately without that the motor first go lower in rpm.

The fuel line is also been replaced.
The filter is still the Original.

The low circuit is plugged. Take out the low speed adjustment and follow the circuit back till you find the plugged hole . Might be under the welch plug. Common problem with old saws.

Hey
Low speed adjustment = idle needle? If yes then i have removed this and the hole was open.
The first, second and third idle hole is also open.

 

[dougand3]

Let's make sure we're talking about the same adjustments. Low and High needles work internally. And then the Idle (or TAS or LA or T) Screw works externally. Here is a Pioneer P26E Idle Screw - CW turn increases fuel flow/ higher idle.

 

[Moondust]

Hello

i've used your picture to explane:

I've set the idle needle (which makes adjustments inside the carburator) to 1 and 1/4 turn.
The adjust throttle is completely turned clockwise but this is sitll not enough to keep the saw running.

And there is only a idle needle, there is no high speed needle.

Sorry for the misunderstanding, but i'm using the names that i find in the Walbro documentation.

 

[dougand3]

Yes, you have it correct. We're on the same page. Like 2stroke said above - you're going to need another carb disassembly and clean out the tiny holes under the welch plug.

 

[Moondust]

Thanks, i am happy that we are talking about the same thing.

Now the part that i need to check. Is it this part on the picture? Blue mark.

Do i need to check the Inlet needle valve also? this part i didn't renew.

And one other thing i noticed.
After i run the saw for a few moments and i let the throttle go to the idle position the saw stops working and sometimes a few seconds later there comes some petrol out on the venting hole (on the picture in the previous post it's the first black tube).

 

[HarleyT]

You need to take your carb apart and remove your circuit plate and take some pics. Your kit may not have provided the correct gasket or diaphram, and all of the back and forth will be useless until you do this.
Also find the remains of what you took out.

 

[pioneerguy600]

That circuit plate and its gasket is usually the culprit in these carb rebuilds, the exact gasket has to be used that matches the carbs circuitry.

 

[Moondust]

I thought i used the right one. (Right one on the first picture)..
But i will open the carburator again and check this part, i will also take some pictures of the old one and the one that i use now.

 

[HarleyT]

I have had carbs that had a circuit plate that was different than the gaskets/diaphrams in the correct kit.
We are talking about a 45 year old saw.......

 

[pioneerguy600]

Some of them have a real small diameter screen held in place by a tiny snap ring, that screen gets so compromised that nothing can get through it and its a ***** for most to get them out and replaced. I have seen times the snap ring was rusted in place, took a lot of WD40 and working with a dental pick to get the ring and screen out.

 

[Moondust]

I've got the carburator open again.
Here are some pictures from inside

The 3 idle holes are open, and the connection hole to the idle needle is also open.

This is the gasket under the Circuit Plate.

The Circuit plate:

And the Metering gasket and diaphragm:

So i hope this is helpfull.

 

[HarleyT]

Looks pretty rough.
Didn't get a full kit?
Look closely at the holes/etc under the circuit plate gasket.

 

[2stroke_shaman]

I would soak that carb in a can of gunk carb cleaner. It will take off all that black goo of death . lol Then a blow out with compressed air.

 

[pioneerguy600]

That carb is filthy inside, its a wonder it runs at all, I bet the idle circuits are clogged up badly. It does look like the circuit plate used matches the original correctly.

 

[HarleyT]

That carb is filthy inside, its a wonder it runs at all, I bet the idle circuits are clogged up badly. It does look like the circuit plate used matches the original correctly.

Don't hold back!!

Tell it like it is!!

 

[Moondust]

Thanks for the info, but i've got a couple questions:

Didn't get a full kit?

What do you mean by not a full kit?
In my first post i put a picture of the kit that i have. And the blue circles are the parts that i use so far.
The rest of the parts i still have.
Is there something that i didn't see to renew expect the Inlet Needle Valve.

That carb is filthy inside, its a wonder it runs at all, I bet the idle circuits are clogged up badly. It does look like the circuit plate used matches the original correctly.

How do you mean?
The Gasket circuit plate looks the same as the one that came out and the Circuit plate itself is the original.

 

[HarleyT]

For some reasons, the pics are not coming back up for me.

But I would disassemble the carb again, all the way. Put it in a can of gas mix for a while, let the gas soften up some of that gunk, and clean everything real good. Try to get rid of that black gunk. Make sure all of the tiny holes are clean.
Put in the new needle and lever, the wear on that lever makes the lever adjustment out of whack, just from that wear depression alone.