020av won't rev unless sideways?

[volks-man]

new to me recently, right off the self the saw would pop with fuel sprayed in the carb but not run on it's own. so i drained the several years(?) old gas and cleaned and freshened the carb. at a glance the intake and impulse look good, the fuel line o.k. (but i want to replace it anyway).

now it starts up right, idles o.k. revs up just fine.... for a short while.
after a minute or so the saw will not rev up. it acts like it hits a timing advance wall at maybe 2-3 times idle speed. the h-screw has no effect while this is happening.
while fiddling with the saw i turned it clutchside up while holding the trigger wide open. after a second or two the saw revved up like nobody's business!!! this is a snappy little beast! return to upright and moments later it won't rev up. recoil side up did not have the same effect. through all this it still idles o.k.
it doesn't seem like it is leaning out. it is still smoking a little blue and doesn't have that hollow hesitation like when your lowside is slightly lean.

any ideas?

 

[ericjeeper]

Stuck clunk. Or crank seals.. Likely crank seals.

 

[Bowtie]

Damn them 020's I hate them.................opcorn:

 

[lone wolf]

new to me recently, right off the self the saw would pop with fuel sprayed in the carb but not run on it's own. so i drained the several years(?) old gas and cleaned and freshened the carb. at a glance the intake and impulse look good, the fuel line o.k. (but i want to replace it anyway).

now it starts up right, idles o.k. revs up just fine.... for a short while.
after a minute or so the saw will not rev up. it acts like it hits a timing advance wall at maybe 2-3 times idle speed. the h-screw has no effect while this is happening.
while fiddling with the saw i turned it clutchside up while holding the trigger wide open. after a second or two the saw revved up like nobody's business!!! this is a snappy little beast! return to upright and moments later it won't rev up. recoil side up did not have the same effect. through all this it still idles o.k.
it doesn't seem like it is leaning out. it is still smoking a little blue and doesn't have that hollow hesitation like when your lowside is slightly lean.

any ideas?

you can test the impulse and fuel lines with a vacum tester i suggest you pressure test and vac test that saw sounds like a leak would be right.i have worked on lots of them and i can help you with it if needed.how old is the saw?

 

[volks-man]

Stuck clunk. Or crank seals.. Likely crank seals.

whatsa clunk?

i thought about the crank seals too but the 026 i just replaced the flywheel seal on was kinda opposite. it ran wide open but didn't idle.

is this a common 020av thing?

 

[volks-man]

you can test the impulse and fuel lines with a vacum tester i suggest you pressure test and vac test that saw sounds like a leak would be right.i have worked on lots of them and i can help you with it if needed.how old is the saw?

1977? it is a top handle with a chain brake.
i think acres site said 1977.

whats the deal with the runs on one side thing?

 

[lone wolf]

whatsa clunk?

i thought about the crank seals too but the 026 i just replaced the flywheel seal on was kinda opposite. it ran wide open but didn't idle.

is this a common 020av thing?

not common but the carbs stink.somtimes the impulse has a tiny hole it should be tested

 

[volks-man]

not common but the carbs stink.somtimes the impulse has a tiny hole it should be tested

true, it should.

the whole saw needs presure/vacuum.

time and time again you guys tell me to do that first.... one day it will sink in.

 

[lone wolf]

1977? it is a top handle with a chain brake.
i think acres site said 1977.

whats the deal with the runs on one side thing?

that ones old sounds like air leak some act like that when you turn em who knows why?thats not the year the carb was bad mine are though.hey u try a new filter

 

[lone wolf]

that ones old sounds like air leak some act like that when you turn em who knows why?thats not the year the carb was bad mine are though.hey u try a new filter

do you have a pressure / vac test or access to one?

 

[lone wolf]

Damn them 020's I hate them.................opcorn:

do you have one with a problem?

 

[volks-man]

that ones old sounds like air leak some act like that when you turn em who knows why?thats not the year the carb was bad mine are though.hey u try a new filter

fuel filter?
nah, i just looked at it. it wasn't caked in gunk so i left it.
there is no air filter. but i wasn't cutting wood with it.

the carb is a walbro wt15. the inlet screen was gunked up bad and there was a little dried up residue here and there. other then the screen it wasn't that bad.

 

[lone wolf]

fuel filter?
nah, i just looked at it. it wasn't caked in gunk so i left it.
there is no air filter. but i wasn't cutting wood with it.

the carb is a walbro wt15. the inlet screen was gunked up bad and there was a little dried up residue here and there. other then the screen it wasn't that bad.

could be the carbs dirty too you take it all apart and spray cleaner through the jets?

 

[volks-man]

do you have a pressure / vac test or access to one?

unfortunately i do have a vacuum pump. i hate having to use it cuz then i gota do seals!!!
for the pressure test i use a regular imprecise air gauge and just keep the pressure on the low side of between 5 and 10 psi. not real precise but if you are careful, it works.

 

[volks-man]

could be the carbs dirty too you take it all apart and spray cleaner through the jets?

i don't touch welch plugs.
other than that i sprayed out every orifice and hole on the carb with the h/l screws out and then low pressure blow the carb out/off.

 

[Bowtie]

do you have one with a problem?

I had 2 that I spent wayyy too much time on. I finally said to hell with them and took a sledge hammer to them.

































































































































(Just kidding, I sold them) I still hate them things.

 

[lone wolf]

unfortunately i do have a vacuum pump. i hate having to use it cuz then i gota do seals!!!
for the pressure test i use a regular imprecise air gauge and just keep the pressure on the low side of between 5 and 10 psi. not real precise but if you are careful, it works.

first vac test the fuel and impulse lines off the saw see if the hold.

 

[ericjeeper]

Take a small saw.Hold it not running up to your ear. roll it side to side.. listen for the "Clunk" The clunk/fuel filter pickup/weighted thingamabob in the fuel tank is commonly referred to as a "Clunk"

 

[volks-man]

whatsa clunk?

Take a small saw.Hold it not running up to your ear. roll it side to side.. listen for the "Clunk" The clunk/fuel filter pickup/weighted thingamabob in the fuel tank is commonly referred to as a "Clunk"

genius!!!
i will remember this term, "CLUNK"!

 

[pioneerguy600]

Have worked a few of the 020`s over and had one that was acting like the one you described. Did not have any leaking seals, idled ok but would spool up then loose it and run at 1/3 throttle, tip it up with the clutch side down and it would quickly pick up the revs. After a couple of teardowns I realised that the moulded fuel line to the carb was not fitting tight enough, a new line fixed this problem, check to see how well the line fits to the carb.
Pioneerguy600