X21ZPN 2 Stroke LB Help Needed

Milanomike

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Hi,

Just joined forum as I've never had any issues with my 2 stroke Lawn Boy in 30+ years. I've got as S21ZPN (S/N G263C0763) that I was using this morning to mow. I am original owner of this machine and love it!

Unfortunately, I pushed it under a mostly dead spruce and a short branch must have hit the carb controls under the hood/cover as all of a sudden it went into what I'll call a low idle, moving throttle lever had no effect. It eventually stalled out and would not restart.

I pulled cleaner and carb and even with the service manual can figure out where to attach the long end of the governor spring. At a minimum I need to correctly reattach spring and reinstall carb to see if she'll run. After cleaning things up a bit, nothing appears broken or really damaged, but I'm not an expert on these. Further troubleshooting after i get it back together if needed.

Thanks for any help here.

Mike
 

Milanomike

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Ignore, as I found where the spring hooked up to. She started on 2nd pull!
 

Milanomike

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Yeah, got lucky here, mowed back yard before the rain, seemed to run well (as always). Would like to check rpm, but don't have a tach, going by sound good enough?
 

FuzzyDriver

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Yeah, got lucky here, mowed back yard before the rain, seemed to run well (as always). Would like to check rpm, but don't have a tach, going by sound good enough?
Lotsa people do. Sometimes I do, sometimes I hook up my old, old car tuneup meter to it, power it up with an external battery, and divide the indicated RPM by 2 (2-stroke vs 4-stroke). Lots a trouble, not much worth. : )

BTW, I have a new S21ZSN, the self-propelled version of your mower, I bought from a Lawnboy dealer going out of business. It had never even had gas in the tank when I bought it.
 
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Milanomike

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Interessting, I did exactly that with my old Craftsman dwell tach from many years ago, it pegged it at 6000 rpm. i'll need to look, but don't think it goes higher. Anyhow my mower is spinning at 3000 rpm minimum.
 

FuzzyDriver

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Yup, you're over 3000 RPM. What RPM are you trying to get? Should be between 2400 and 3200 RPM at max throttle. Maybe you should adjust at your 6000 peg so you know you're not running too fast.
 

Milanomike

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yes, i'm thinking it is too fast. I simply turn the plastic wheel under the governor vane to adjust, correct?
 

FuzzyDriver

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yes, i'm thinking it is too fast. I simply turn the plastic wheel under the governor vane to adjust, correct?
Yes. I wouldn't have used the word "simply" to describe it because of how far under the shroud you have to reach, so the only safe way to do this is while the engine isn't running.
 

Milanomike

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Thanks, just checked my service manual, it states 3000 - 3300 rpm at normal setting, whatever normal is. In the next day or so, i should be able to adjust it to say 3000 at fast or max setting (can't recall what is states on throttle lever at the moment). Thanks again, think I got it.
 
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