Stihl 044 what did i do wrong? EDIT: I think It's Fixed

[pioneerguy600]

They available to put in?

They can be found but rather pricey, I just rebuild them.

 

[ballisticdoughnut]

Leaking checkvalve assembly.

Beat me to it. Was thinking the same.

 

[J D]

Op, did you blow the carb out with compressed air or perhaps clean it with brakeparts cleaner or similar?

 

[Indy Red]

That notch feeling is likely the magnet in flywheel passing by the ignition coil.

Yep that is what it was, feel bit of on ***** on that one This is my first rebuild though so all this stuff helps me to get better

 

[Indy Red]

Ok here are the pictures:

 

[Indy Red]

None of the wear can be felt with a finger nail and is on the intake side, the carb needle was the original and was replaced with a Walbro carb kit, carb is Walbro HD-15B, The needle has some king of rubbery substance on it that was not present on the new needle.

The inside of the cylinder was like black oil and the piston was very wet with it, It was actually dripping from the exhaust on the muffler

 

[Indy Red]

Op, did you blow the carb out with compressed air or perhaps clean it with brakeparts cleaner or similar?

Was cleaned with carb cleaner, sadly don't have an air compressor

 

[Indy Red]

They can be found but rather pricey, I just rebuild them.

If it was a leaking check valve would it pressure/vac test ok?

 

[pioneerguy600]

If it was a leaking check valve would it pressure/vac test ok?

Yes, you are only checking the metering valve with a pressure and vac test, the idle and Wot circuits are wide open to the carb throat/venturi.

 

[pioneerguy600]

Was cleaned with carb cleaner, sadly don't have an air compressor

Carb cleaner destroy`s the coating on the tiny disc inside the check valve, I have rebuilt carbs that only had a fibrous disc left after the carb cleaner had dissolved the rubber like coating from the disc. Carb cleaner is too harsh for any rubber/ viton and soft diaphragm materials. Ultrasonic cleaning is best for any carbs with a high speed check nozzle.

 

[pioneerguy600]

Ok here are the pictures: View attachment 1190658

The needle valve tip looks like it is buggered up in your pic, it is not a very clear pic but the tip appears blunted and also I can see where someone attempted to remove the brass jet located in the bowl of the carb, the slot is distorted. Best bet would be to get a new carb as fixing the one you have may lead to requiring many parts and someone that knows carbs well to install and adjust the old one to make it function correctly.

 

[Indy Red]

The needle valve tip looks like it is buggered up in your pic, it is not a very clear pic but the tip appears blunted and also I can see where someone attempted to remove the brass jet located in the bowl of the carb, the slot is distorted. Best bet would be to get a new carb as fixing the one you have may lead to requiring many parts and someone that knows carbs well to install and adjust the old one to make it function correctly.

I will check on prices, but think they are really expensive, the needle valve in the pic is the old one and had some form of coating on it that would break away, the tip seems to have gone off it, would prefer to try to rebuild, so I have to order a check valve and what else would you recommend?

Also would the wear on the cylinder and the wetness of everything be caused but running lean then over fueling?

 

[babaoriley]

I will check on prices, but think they are really expensive, the needle valve in the pic is the old one and had some form of coating on it that would break away, the tip seems to have gone off it, would prefer to try to rebuild, so I have to order a check valve and what else would you recommend?

Also would the wear on the cylinder and the wetness of everything be caused but running lean then over fueling?

Grab a Chinese carb for testing it’s cheap enough. Hipa is the only one I would buy from.

 

[lone wolf]

I will check on prices, but think they are really expensive, the needle valve in the pic is the old one and had some form of coating on it that would break away, the tip seems to have gone off it, would prefer to try to rebuild, so I have to order a check valve and what else would you recommend?

Also would the wear on the cylinder and the wetness of everything be caused but running lean then over fueling?

Those OEM carbs that expensive?

 

[pioneerguy600]

I will check on prices, but think they are really expensive, the needle valve in the pic is the old one and had some form of coating on it that would break away, the tip seems to have gone off it, would prefer to try to rebuild, so I have to order a check valve and what else would you recommend?

Also would the wear on the cylinder and the wetness of everything be caused but running lean then over fueling?

Does the new needle valve have the soft Viton tip on it? A new check valve would be a good choice but all the fuel passages should be cleaned out using jet drills to restore them to new condition, all Welsh plugs checked for leaking, they must be airtight, check that the L and H speed screws are tight fitting in their threads and that the tips are not damaged, post a good clear pic of those tips if you can. Many of the carb kits these days are not quite right as replacements for older carbs, the metering diaphragms do not always function the same as older carbs metering diaphragms did, the center button on the metal weight disc can be off in size and construction, just throwing a carb rebuild kit into a carb can render it useless. I have many carbs shipped to me for full rebuilds after previous owners installed a new kit and made the carb worse rather than better. If you decide to punch the high speed check valve out of the carb body remember to back the adjusting needles out, better to remove them than bend the tips. A rich running carb causes wet and blackened cylinders/pistons but that seldom causes wear of the cylinder, can cause carbon deposits on the piston crown and in the exhaust port. If that carbon breaks loose and jambs between the piston and cylinder that can cause carbon scoring marks, more so on the sides of the piston but usually does not score the hard plating on the cylinder walls. Running lean causes much more damage as less oil causes more friction that can melt the softer aluminum piston, that melted aluminum sticks to the cylinder all we call transfer.

 

[altatim]

Have you considered fuel pooling due to too much on the L screw? I was struggling to understand why my 044 would run just like yours but it would hold 15inHg overnight on three different occasions. Turns out I was a bit too rich on the low and and was getting fuel pooling that would make it stall when tilted one way but not the other. Got it re-tuned and it was a totally different saw. Start from scratch again if you suspect this is the problem. For my saw it was open about 1/16-1/8 of a turn too much and it caused the issues you are describing.

 

[Indy Red]

Those OEM carbs that expensive?

About $220 sadly

 

[Indy Red]

Does the new needle valve have the soft Viton tip on it? A new check valve would be a good choice but all the fuel passages should be cleaned out using jet drills to restore them to new condition, all Welsh plugs checked for leaking, they must be airtight, check that the L and H speed screws are tight fitting in their threads and that the tips are not damaged, post a good clear pic of those tips if you can. Many of the carb kits these days are not quite right as replacements for older carbs, the metering diaphragms do not always function the same as older carbs metering diaphragms did, the center button on the metal weight disc can be off in size and construction, just throwing a carb rebuild kit into a carb can render it useless. I have many carbs shipped to me for full rebuilds after previous owners installed a new kit and made the carb worse rather than better. If you decide to punch the high speed check valve out of the carb body remember to back the adjusting needles out, better to remove them than bend the tips. A rich running carb causes wet and blackened cylinders/pistons but that seldom causes wear of the cylinder, can cause carbon deposits on the piston crown and in the exhaust port. If that carbon breaks loose and jambs between the piston and cylinder that can cause carbon scoring marks, more so on the sides of the piston but usually does not score the hard plating on the cylinder walls. Running lean causes much more damage as less oil causes more friction that can melt the softer aluminum piston, that melted aluminum sticks to the cylinder all we call transfer.

I think it must have had a Viton tip on it, the new kit was a normal one, If it matters I will order one and do the things you have posted then see where I am at with it.

EDIT just checked again and it does have a black rubberish tip, the old one was orange though, will also use the old gaskets to rule that out

 

[Mad Professor]

Carb cleaner destroy`s the coating on the tiny disc inside the check valve, I have rebuilt carbs that only had a fibrous disc left after the carb cleaner had dissolved the rubber like coating from the disc. Carb cleaner is too harsh for any rubber/ viton and soft diaphragm materials. Ultrasonic cleaning is best for any carbs with a high speed check nozzle.

Starting fluid can be used to flush the carb passages. Cans come with a nozzle/tube for the valve.

 

[Indy Red]

Starting fluid can be used to flush the carb passages. Cans come with a nozzle/tube for the valve.

Just checked the can i used and it was easy start, always thought them and carb cleaner were the same thing