Trigger Man
Addicted to ArboristSite
Is the check valve working , I'll bet the carb is screwed.
Walbro WA Carb Problems
- Thread starter blsnelling
- Start date
Help Support Arborist Forum:
Where's the check valve?
I just had it apart again. I see no where for a governor. Also no welch plugs.
If anyone has a 020 carb and/or coil, I'd be happy to pay shipping both ways just to try them out on my saw, even if you don't want to sell them.
Thanks for all the input guys!
Last edited:
Can a new carb be bought for this saw? I'm not having any luck finding anything online.
litefoot
Addicted to ArboristSite
Brad,
The check valve feeds fuel from the high speed circuit. As air rushes through the venturi, the change in pressure opens the check valve and fuel is sucked into the throat. High pressure air (while cleaning) can ruin it.
However, when they go bad, the saw floods...I mean REALLY floods; so much so that the saw wouldn't restart as easily as yours.
Also, I'd go ahead and get a bar/chain on the saw. The load on the engine will give you a better feel of what's really going on. Trust me. It really makes a difference.
At this point, I'd try a pressure test on the carb. Pop off the fuel filter and pressure the carb from there up to about 7 psi and see if it holds pressure. You'll at least know the fuel line and the pump side of the carb are good.
Thanks for the tips. The saw has had the B&C on it numerous times today. I gave up on reinstalling it every time. I'll try the pressure test tomorrow. Wait a minute. I don't have a pressure pump, only a vacuum pump.
litefoot
Addicted to ArboristSite
Thanks for the tips. The saw has had the B&C on it numerous times today. I gave up on reinstalling it every time. I'll try the pressure test tomorrow. Wait a minute. I don't have a pressure pump, only a vacuum pump.
Looking at your video, I'm not convinced that some more tuning on the H, L and LA won't fix it. It sure seems to start easy enough and that's a good sign that you're pretty close.
Brmorgan
Addicted to ArboristSite
- Joined
- Apr 22, 2008
- Messages
- 3,248
- Reaction score
- 348
If you have a little hand bike tire pump you should be able to rig something up with a schraeder valve fitting and a piece of fuel line. I have something like that somewhere around the shop downstairs, though I've never used it for pressurizing carbs. I'm watching this thread with interest though because I've had many of the same questions and problems these little Walbro carbs - I'm fighting one in a Husky 36 at the moment.
Back at the beginning of the month when I was down to see Bob in Kamloops ("bigbadbob" here) he showed me an older 020 on his shop floor, and mentioned something about the carb being screwed and needing to be replaced since it couldn't be rebuilt for some reason. He also said that someone here had told him about that problem (I forget who), and it sounded familiar to me too.
Back at the beginning of the month when I was down to see Bob in Kamloops ("bigbadbob" here) he showed me an older 020 on his shop floor, and mentioned something about the carb being screwed and needing to be replaced since it couldn't be rebuilt for some reason. He also said that someone here had told him about that problem (I forget who), and it sounded familiar to me too.
Trust me, I've tried everything
! Actually, I can run the H needle all the way in and it doesn't run a bit differently. I didn't mean to hold that bit of info from you guys. I've just tried so many things it's hard to remember.
I've never had one of those down and was just going by the IPL.....it is listed as #20
There's no PN by that item though. I believe that means its NA.
almondgt
Addicted to ArboristSite
Trust me, I've tried everything
Is switching the high/low needles on the carb an option? Saved me once on a 08s some time back
:check:
I tried that too. It can't be done. The long needle only fits in the H hole.
almondgt
Addicted to ArboristSite
Look out, there is more of the same out there. Bad rap for the 020av!
http://cgi.ebay.com/STIHL-020-020AV...emQQptZLH_DefaultDomain_0?hash=item3efa62aa51
:greenchainsaw:
Look out, there is more of the same out there. Bad rap for the 020av!
http://cgi.ebay.com/STIHL-020-020AV...emQQptZLH_DefaultDomain_0?hash=item3efa62aa51
:greenchainsaw:
I saw that one. Sounds like he's got similiar problems. I will beat this thing, even if I have to pay $83 for a new carb, lol!!!!!!!!!!!!!!
I am planning on bidding on this one, LINK. So please don't bid it up on me, lol! It should have a good coil, and perhaps a good carb.
Last edited:
almondgt
Addicted to ArboristSite
I saw that one. Sounds like he's got similiar problems. I will beat this thing, even if I have to pay $83 for a new carb, lol!!!!!!!!!!!!!!
I am planning on bidding on this one, LINK. So please don't bid it up on me, lol! It should have a good coil, and perhaps a good carb.
Did you soak the carb in carb cleaner overnight at any point? Just reaching now!
:monkey:
If you can run the H needle all the way inAnd no change,
Then fuel is getting through the carb somehow.
I would say it rules out ignition problems.
I think to save yourself some time i would try
a known good carb and go from there.
Myself i would disassemble the carb again and just
look at it, Study it, all the passages have to go somewhere.
You need to know exactly how the carb works before you can repair a problem like this.
Just a thought.
Lee
Then fuel is getting through the carb somehow.
I would say it rules out ignition problems.
I think to save yourself some time i would try
a known good carb and go from there.
Myself i would disassemble the carb again and just
look at it, Study it, all the passages have to go somewhere.
You need to know exactly how the carb works before you can repair a problem like this.
Just a thought.
Lee
I don't think there are any hidden passages on this carb. The removable plate makes that possible.
If I have to see the insides of this carb one more time...................!!!!!!!!!!!!
The link to lawnmowerpros gives a great pictorial of how this carb works.
almondgt
Addicted to ArboristSite
I don't think there are any hidden passages on this carb. The removable plate makes that possible.
If I have to see the insides of this carb one more time...................!!!!!!!!!!!!
I would try soaking it, sometimes what you think and what happens is two too to different things. Just my .02
...sometimes what you think and what happens is two too to different things. Just my .02
Very true!
