Help with 028wb

[gunrush128]

Okay, so I finally decided to ask for help on this stubborn saw. I've been tinkering with this to get it running for my neighbor.
I started by rebuilding the carb, replacing the fuel line/filter. I then set the H/L needles to factory specs. It would start with high idle/choke engaged, but as soon as I took it off choke, it would stall almost immediately. At this point, the air filter and muffler were soaked with gas.
After some reading on here, I decided to upgrade to electronic ignition by swapping on a coil from an 029super. Now I've got it idling fine, and revving up fine, but when I put the tach on it to tune the high speed circuit, I couldn't get it to adjust past 10k or so... Now I haven't leaned out the H needle all the way, but I should expect to see some fluctuations with a half turn of adjustment on the H needle, right? I didn't want to try adjusting much further than that with fear of ruining a very nice oem P&C.
Next I returned the H needle to factory specs(1 1/4 turn, I believe) and tried putting the saw in wood. To me it feels like a dog, and sounds like it's 4-stroking in the cut.
I also noticed, when held wide open in the cut, it almost sounds like it's misfiring...
The only other thing I can think of, is maybe I should swap the flywheel from the 029super also? I know there was a little controversy over whether it mattered or not, but I couldn't find a definitive 'yes' or 'no'

Any help or advice would be greatly appreciated!


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[Jeff Lary]

Hi this will most likely not help but I have seen people on here speak of limited and unlimited coils before. Is it possible you have a limited one? Even if this is crazy,.. someone knows what's up with your saw and when they see my feeble attempt to help you they may decide to chime in and voilà the problem is solved. Maybe this will get things going for you good luck Jeff

 

[gunrush128]

Hi this will most likely not help but I have seen people on here speak of limited and unlimited coils before. Is it possible you have a limited one? Even if this is crazy,.. someone knows what's up with your saw and when they see my feeble attempt to help you they may decide to chime in and voilà the problem is solved. Maybe this will get things going for you good luck Jeff

I could be wrong, but I don't think that the coil on the 029s was limited, and definitely not around the 10,000 mark.


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[watsonr]

clean the carb again. make sure the metering needle is set correctly. if it's 4-stroking, its rich. check the tip of the H needle to make sure its not rounded over. Also, you can put the carb in a bucket of water with some pressure on the fuel inlet. It should hold up about 10 psi before the needle lifts. And you'll be able to tell if it's leaking right away by the bubbles.... probably whats happening.

you should be able to control the high RPM by the H screw, if not something with the carb is wrong. Small bursts of running while tuning shouldn't hurt it... just don't run it at high speed for any extended periods in a lean condition. You should also be able to close the H screw completely and when you goose it, should die. The 1 1/4 is the recommended starting point, if it runs at 3/4 and isn't lean, you won't hurt the saw.

coils aren't limited at 10,000, your problem is the carb.

 

[Duane(Pa)]

clean the carb again. make sure the metering needle is set correctly. if it's 4-stroking, its rich. check the tip of the H needle to make sure its not rounded over. Also, you can put the carb in a bucket of water with some pressure on the fuel inlet. It should hold up about 10 psi before the needle lifts. And you'll be able to tell if it's leaking right away by the bubbles.... probably whats happening.

you should be able to control the high RPM by the H screw, if not something with the carb is wrong. Small bursts of running while tuning shouldn't hurt it... just don't run it at high speed for any extended periods in a lean condition. You should also be able to close the H screw completely and when you goose it, should die. The 1 1/4 is the recommended starting point, if it runs at 3/4 and isn't lean, you won't hurt the saw.

coils aren't limited at 10,000, your problem is the carb.

Nice Post!! All I would add is that the metering lever setting can be very fussy. Did you use compressed air? Big no-no.

 

[woods works]

I had an 028 that had me pulling my hair out (whats left of it) with same symptoms as yours. It turned out to be a weak spring that keeps the choke flap open in the air filter. Try running it without the air filter.

 

[bikemike]

Yeah i would say the carb is the issue. But there could be a chance the new coil might be running the wrong timing or fly wheel key could be broke and rotate to a retarded position. Start with the carb first

 

[gunrush128]

I've had this carb apart at least 3 times. I've run it in my ultrasonic cleaner for about 10 minutes. Pulled welch plug, then cleared all passages with carb cleaner. Reassembled with new diaphragms, new needle, made sure metering lever was set to the 'level' position.
I am almost positive that the carb is totally clean. I will check the shape of the H-needle.


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[watsonr]

Nice Post!! All I would add is that the metering lever setting can be very fussy. Did you use compressed air? Big no-no.

NO, use a small hand pump or a bulb.

 

[bikemike]

I had an 028 that had me pulling my hair out (whats left of it) with same symptoms as yours. It turned out to be a weak spring that keeps the choke flap open in the air filter. Try running it without the air filter.

Il need to keep that in mind for the 026 filters. Nice

 

[gunrush128]

Yeah i would say the carb is the issue. But there could be a chance the new coil might be running the wrong timing or fly wheel key could be broke and rotate to a retarded position. Start with the carb first

There were a few posts that said the timing was different on the old 028wb flywheels, vs the newer electronic coil, but then I read posts that said it didn't make a difference. I have a flywheel for an 029s sitting on the shelf...


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[bikemike]

There were a few posts that said the timing was different on the old 028wb flywheels, vs the newer electronic coil, but then I read posts that said it didn't make a difference. I have a flywheel for an 029s sitting on the shelf...
Guess the easy way to find out would be put old coil on with a line on the flywheel and mark the case and try the new coil and se if the differ a more the 3 degrees

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[bikemike]

NO, use a small hand pump or a bulb.

Brake clean has all the pressure you need and cleans without the damage

 

[watsonr]

Brake clean has all the pressure you need and cleans without the damage

we were talking about using air pressure to test the metering lever. It should lift with a certain pressure and by using air, reveal a leak by the bubbles. Brake cleaner is great stuff!

 

[gunrush128]

I will have a chance to dig back into it tomorrow. If I can get the flywheel off easily enough, I might just try the other flywheel first.


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[HarleyT]

I will have a chance to dig back into it tomorrow. If I can get the flywheel off easily enough, I might just try the other flywheel first.


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Hell no!!!!! The 029/ms290 flywheel will not fit, the old flywheel is fine.!!!!

 

[HarleyT]

Okay, so I finally decided to ask for help on this stubborn saw. I've been tinkering with this to get it running for my neighbor.
I started by rebuilding the carb, replacing the fuel line/filter. I then set the H/L needles to factory specs. It would start with high idle/choke engaged, but as soon as I took it off choke, it would stall almost immediately. At this point, the air filter and muffler were soaked with gas.
After some reading on here, I decided to upgrade to electronic ignition by swapping on a coil from an 029super. Now I've got it idling fine, and revving up fine, but when I put the tach on it to tune the high speed circuit, I couldn't get it to adjust past 10k or so... Now I haven't leaned out the H needle all the way, but I should expect to see some fluctuations with a half turn of adjustment on the H needle, right? I didn't want to try adjusting much further than that with fear of ruining a very nice oem P&C.
Next I returned the H needle to factory specs(1 1/4 turn, I believe) and tried putting the saw in wood. To me it feels like a dog, and sounds like it's 4-stroking in the cut.
I also noticed, when held wide open in the cut, it almost sounds like it's misfiring...
The only other thing I can think of, is maybe I should swap the flywheel from the 029super also? I know there was a little controversy over whether it mattered or not, but I couldn't find a definitive 'yes' or 'no'

Any help or advice would be greatly appreciated!


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It is now just running rich, and you need to go back into the carb and fix it correctly!! Describe what you did in detail when you "rebuilt" it.

 

[gunrush128]

Hell no!!!!! The 029/ms290 flywheel will not fit, the old flywheel is fine.!!!!

I guess you're right. I though I read somewhere that they would be a direct replacement, but after a little more digging, I see that you're right. Thanks!


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[HarleyT]

Yeh, the reason hat I sell flywheels is from folks trying to remove them for no reason.

 

[gunrush128]

It is now just running rich, and you need to go back into the carb and fix it correctly!! Describe what you did in detail when you "rebuilt" it.

-disassembled
-removed welch plug, screen, metering lever and needle, high and low needle
-ran in heated ultrasonic cleaner(50/50 pine sol and water) for 10 minutes
-cleaned all passages with carb cleaner
-installed new; welch plug, screen, metering lever, both diaphragms, and gaskets
-returned high and low needles to factory setting


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