I never remember to do it myself, but that camera is more useful while disassembling than while assembling.
Walbro WA Carb Problems
- Thread starter blsnelling
- Start date
Help Support Arborist Forum:
I never remember to do it myself, but that camera is more useful while disassembling than while assembling.
This thing still has me stumped. I bet I've had it apart a dozen times. It doesn't want to rev. Compression is 155. I don't know if it's a bad carb, bad coil, or timing being off since it has the Nova module. I tried reversing the polarity. It still ran but was worse. I advanced the timing 1 1/2 keys like my 031. I though it was fixed. Then after it warms up, it won't take throttle again. I'm about to pull my hair out on this one!!!!!!!!!!!!!!!!!!!!! I'm thinging about making a video so that you guys can help me diagnose it. I'm at a loss at this point. No wonder it was free
Help me out here guys. Ignition or carb? The timing is currently advanced 1 1/2 key widths. It didn't want to rev at all before that. The H is 1 turn out, and you see me reset it at the end to make sure. Why would it rev at first, and then just fall on its face?
Disclaimer: Never run a saw at max RPMs without the bar and chain. I've had this saw apart probably a dozen times today trying to diagnose the problem. I'm giving it short bursts of high RPMs at the beginning, but not leaving it there for any time at all.
<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/h54il3qkJOs&hl=en_US&fs=1&rel=0"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/h54il3qkJOs&hl=en_US&fs=1&rel=0" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>
Disclaimer: Never run a saw at max RPMs without the bar and chain. I've had this saw apart probably a dozen times today trying to diagnose the problem. I'm giving it short bursts of high RPMs at the beginning, but not leaving it there for any time at all.
<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/h54il3qkJOs&hl=en_US&fs=1&rel=0"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/h54il3qkJOs&hl=en_US&fs=1&rel=0" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>
I was just digging through the IPL again. I am missing the metal ring that goes in the intake boot, behind the carb. I don't know if that could be related or not.
Sorry if I am stating obvious things you already have eliminated...
Did you pull the Welch plugs on the carb job?
I've heard complaints about weak sparks with the Novas...have you cleaned/replaced the spark plug?
Does your tach run on induction? If the reading is erratic, it might help point out an ignition problem.
Did you pull the Welch plugs on the carb job?
I've heard complaints about weak sparks with the Novas...have you cleaned/replaced the spark plug?
Does your tach run on induction? If the reading is erratic, it might help point out an ignition problem.
At this point I don't know if it's ignition or carb. Anything would help. Thanks.I have a parts saw here with the carb..
i can pull it apart and take pix if you still need them.
same saw,same carb.
been sitting 10 yrs so would prob need rebuild anyway
See red text above.
Last edited:
almondgt
Addicted to ArboristSite
Is the carb kit oem or aftermarket? Need to locate a different carb to narrow down the problem. Borrowing a different carb a possibility? Almost seems to be sucking air, maybe crank seals or base gasket? :chainsawguy:Not worth pulling any more hair out.
:chainsawguy:
:chainsawguy:
Justsaws
Addicted to ArboristSite
Was one of the new different plugs a CJ-8, if not try that and/or take the current plug gap down to about 1/2-3/4 of what it currently is.
Most likely it is time for a different coil if one of those methods shows improvement.
If it revs once or twice and bogs out after that then you have got to check the vent, etc..
Pain in the ... little saws.
Just saw the video. Get a coil.
Most likely it is time for a different coil if one of those methods shows improvement.
If it revs once or twice and bogs out after that then you have got to check the vent, etc..
Pain in the ... little saws.
Just saw the video. Get a coil.
Last edited:
OEM Walbro carb kit. I do not have another carb to try on it.
Both plugs were new Bosch WSR6. Crank seals are not leaking. I both vacuum and pressure tested. I cracked the fuel cap loose with no change.
almondgt
Addicted to ArboristSite
Anyone got a carb out there to fit this Stihl 020AV? It is cost nothing to beg~
:chainsawguy:
:chainsawguy:
Justsaws
Addicted to ArboristSite
Re-gap the plug down(.016) and try. Sounds like the coil and module are not playing well together. That happens if the coil is marginal or about done.
When you set the air gap did you use the air gap recommend by the manufacturer of the module? Some want it a good bit closer than before.
Also make sure that the ground through the module is tight and clean.
When you set the air gap did you use the air gap recommend by the manufacturer of the module? Some want it a good bit closer than before.
Also make sure that the ground through the module is tight and clean.
Last edited:
Air gap is set at .010".
In the video it sounds like it revs up nice then
starts to run rich and loses rpm. Anything in the
choke area.
Possible needle and seat arn't seating and starting
to flood.
Just a couple thoughts.
Lee
starts to run rich and loses rpm. Anything in the
choke area.
Possible needle and seat arn't seating and starting
to flood.
Just a couple thoughts.
Lee
I suppose anything's possible. It is a new needle, needle lever, and pin.
Trigger Man
Addicted to ArboristSite
I wounder if the metering lever spring is bad? Just a thought? sometimes they get stretched or commpressed too much?
I went and looked at the IPL on that carb and it has a governor built in. Could this be causing your problem? It is # 20 on the attached list.
http://www.lawnmowerpros.com/PDFs/Walbro/WAseries.pdf
http://www.lawnmowerpros.com/PDFs/Walbro/WAseries.pdf
Justsaws
Addicted to ArboristSite
Usually when a carb is flooding out the saw will be difficult to restart after one or two start/stop cycles.
If the coil is weak and the saw cannot maintain spark the rpms and fuel into the cylinder are controlled a little more together so the saw can be restarted many times in a row without having to re-adjust or hold the trigger wide open and pull and pull. Eventually the engine will load up and flood out but typically after far more start/stop cycles than a malfunctioning carb.
Hard to tell. If it has a carb governor that is certainly worth blocking(if possible) off as it is yet another possibility.
tomdcoker
Addicted to ArboristSite
I had one of those saws a while back and finally sold it for someone else to worry with.
The best I remember my would not run as good as yours.
I also talked to a saw shop owner about mine and he told me that the 020 was hard to get the carb. right.
One of the things he told me was to check the impluse from the motor. Some times the hole gets restricted if they have sat for a while. Gummed up from oil and gas residue. Tom
The best I remember my would not run as good as yours.
I also talked to a saw shop owner about mine and he told me that the 020 was hard to get the carb. right.
One of the things he told me was to check the impluse from the motor. Some times the hole gets restricted if they have sat for a while. Gummed up from oil and gas residue. Tom
Gap was at .022. I reset to .016. I may have helped a little.
I just went in and stretched it out a little. No change.
A governor ehh? I HATE those things! Same thing happened with my SXL-925. Thought there was something wrong with it until I found out and blocked the governor. Only thing is, I don't see where a governor would be on this carb. Also, the saw doesn't want to rev at all with a B&C on it.
This last time around, I retarted the timing to 1 key advanced. I could feel it grabbing at me at 1 1/2 keys advanced. Stihll no change. I may go take it back apart one more time tonight to see if I can find a governor on it. I also installed a ring in the carb boot with no change.
