Rebuilding a Stihl 034, should I try it?

[Mad Professor]

Ok if I can't find someone to do it cheaply I'll get the mighty vac. Question for ya, is everything I need included in the mighty vac package? If not what else will I need to get while I'm at harbor freight? Can I get by without a flywheel puller or do I need it? Are there any other tools ya'll can think of besides the t27 torx that I should pick up to finish this project while I'm at harbor freight? Thanks!

Edit: would this work?
https://www.amazon.com/Copap-16PCS-Brake-Bleeder-Vacuum/dp/B077PC8K2W/ref=mp_s_a_1_5?keywords=vacuum/pressure+pump+tester+kit&qid=1563988946&s=gateway&sr=8-5

You need to be able to block off intake/exhaust. Can do so with inner tube "gaskets" and bolting muff/carb on. But be sure leaks are not there. You need to hook up vac/pres, easy way is impulse line if that is solid. A step up/down line connector for that.

Have soapy water handy for pres test. Vac test don't us water unless taking apart right away/drying. WD 40 or oils for that.

 

[dabills]

You need to be able to block off intake/exhaust. Can do so with inner tube "gaskets" and bolting muff/carb on. But be sure leaks are not there. You need to hook up vac/pres, easy way is impulse line if that is solid. A step up/down line connector for that.

Have soapy water handy for pres test. Vac test don't us water unless taking apart right away/drying. WD 40 or oils for that.

Would this work?:

https://www.amazon.com/Copap-16PCS-...mp+tester+kit&qid=1563988946&s=gateway&sr=8-5

 

[cuinrearview]

That would probably work for the vac portion. You still want to be able to test with pressure as well.

 

[dabills]

Ok will this mightyvac work for both the pressure test and the vacuum test?:

https://www.harborfreight.com/mityvac-vacuum-pump-39522.html

 

[Mad Professor]

Like this

https://www.skf.com/mityvac/product...-accessories/hand-pump-kits/mv8500/index.html

 

[cuinrearview]

Nope, the HF one only does vac

 

[cuinrearview]

You want the MV8500. If you look around you should be able to get one ~$55

 

[pioneerguy600]

The 036PRO was one of my first PRO Stihl chainsaws I ported back around 2000, it provided the most gains of any Stihl saw I had done until I started building 026`s a few years back, they have surpassed my expectations but my 036 is not going any where.

 

[Nathan Graff]

Go for the Mityvac 8500. I've broken more than a few of those cheap plastic jobbies. You can either well the tool after, or use it for other things... I hear it's used in some sex toys...

 

[SteveSr]

Here is another thing to check...

Your saw died from being too lean. Either too much air (air leak) or too little fuel. Pull the carburetor and count the turns to lightly closed position. They both should be open about 1 turn from lightly seated. Report back the numbers.

Pull the pump side cover off of the carb... single BIG screw. Remove gasket and the pump diaphragm. Take a photo of what you find inside the carb. What you are looking for is the 1/4" diameter filter screen and any contaminants sitting on top of it. The old style filters had a replaceable foam element that could disintegrate over time, collect in the filter screen and result in fuel starvation. There is a possibility that this killed your saw.

BTW, the carburetor model will help to determine the age of your saw. There may even be a date code on the side of the carb next to the model number. Post a photo once you have cleaned all of the junk off the outside of the carb.

 

[SteveSr]

Pressure testing setup...



I prefer the spark plug injection as it will test the COMPLETE saw all at once... WITHOUT tearing anything apart. Spark plug adapters can be made or bought. This one was made out of an old spark plug, a brass hardware store fitting and some Marine Weld epoxy. Just be sure to seal it with a good o-ring at the cylinder interface.




This is one of the block-off plates made from scrap .090" aluminum and some hardware store 1/8" rubber gasket material. I glued the rubber to the aluminum with contact cement. The spacers in the bag are just a hardware store assortment. You can see them used on the carburetor mounting bolts to hold this blocking plate on. For the muffler plate I just used the regular muffler bolts.

You can also get creative and use the carb and muffler themselves to hold on rubber blocking plates.




This is the Stihl flywheel remover tool. I don't recall it being very expensive. I have heard that this is the same size as one used on certain mopeds which may be less expensive. I'll let someone else chime in with more details on this.

 

[Mad Professor]

You want the MV8500. If you look around you should be able to get one ~$55

You just missed me , see post #45

 

[dabills]

Pressure testing setup...

View attachment 749131 View attachment 749133

I prefer the spark plug injection as it will test the COMPLETE saw all at once... WITHOUT tearing anything apart. Spark plug adapters can be made or bought. This one was made out of an old spark plug, a brass hardware store fitting and some Marine Weld epoxy. Just be sure to seal it with a good o-ring at the cylinder interface.


View attachment 749134

This is one of the block-off plates made from scrap .090" aluminum and some hardware store 1/8" rubber gasket material. I glued the rubber to the aluminum with contact cement. The spacers in the bag are just a hardware store assortment. You can see them used on the carburetor mounting bolts to hold this blocking plate on. For the muffler plate I just used the regular muffler bolts.

You can also get creative and use the carb and muffler themselves to hold on rubber blocking plates.


View attachment 749135

This is the Stihl flywheel remover tool. I don't recall it being very expensive. I have heard that this is the same size as one used on certain mopeds which may be less expensive. I'll let someone else chime in with more details on this.

Any chance I could pay you to send me the plates I'd need to block this thing up? Ordered the mighty vac should be here Friday. Trying to figure out how to get carburetor off now. Will send pics if I get it tonight. There are 2 little screws on bottom and one big one on top, which ones do you want me to turn and which direction?

 

[cuinrearview]

The two bottom ones. Count the number of full turns in until they're seated. The low speed or "L" screw is always closer to the cylinder, the high speed is closer to the filter.

 

[dabills]

The two bottom ones. Count the number of full turns in until they're seated. The low speed or "L" screw is always closer to the cylinder, the high speed is closer to the filter.

1 and 1/4 turns each. Pulling big screw next.

Top days Japan and Zama here are pics of numbers on sides

 

[SteveSr]

1 and 1/4 turns each.

That is about where they should be. So the saw didn't die from a mis-adjusted carb. However, the extra 1/4 turn on the "H" needle may indicate a fuel restriction.

Top says Japan and Zama here are pics of numbers on sidesView attachment 749154 View attachment 749155

The carb is a Zama C3A-S4A. The date is likely 198"8" . Can't be 1978 or 1998.

 

[dabills]

Also just measured bore, pretty sure its 48mm if I measured correctly. Ok back to carb...

 

[dabills]

SteveSr let me know if I can pay you to send me a set of the stuff referenced in your pictures for vacuum test.

This is what I found under big screw:

 

[dabills]

The plan when I get the pump is block off carb and muffler with bicycle tube rubber and use carb and muffler top keep in place. Then pressurize through the impulse line, whatever that is! Lol. Does everyone think this will work?

 

[Mad Professor]

The plan when I get the pump is block off carb and muffler with bicycle tube rubber and use carb and muffler top keep in place. Then pressurize through the impulse line, whatever that is! Lol. Does everyone think this will work?

The dirt/sawdust inside the carb under the plate/on pump diaphragm is normal and builds up over time. There needs to be a vent so diaphragm can pump a crap works it's way inside. It's one of the places to check first for carb problems, sometimes the junk can build up so much the carb won't pump.

Impulse line runs from crankcase under intake manifold to tank housing.

You can block off stuff using inner tube as mentioned.

Here is some reference material. 036 is almost same as 034.

I did a 036 rebuild a while back with pictures, that might help. Do a search