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Discussion Starter · #1 ·
Just picked up an early 90's 14SZ for a whopping $12 at auction. No history on it, but I figured it was worth the gamble. First thing I did was dumped the little bit of fuel that was in it and removed the carb to clean it. No sediment in bowl and jets appeared very clear - it seemed like someone might have had this apart semi-recently but I blew them all out with carb cleaner any way.

Went ahead and put a little fresh fuel in it and tried to start it. No luck. Tried spraying a little ether in the carb and ever so briefly it would run and then immediately die. Repeated that a couple times with same results. It really only runs for the shortest amount of time - less than I've experienced before when I run an engine on just a shot of ether.

Checked compression and I'm getting maybe 45 PSI. That would only be okay if there's a de-compression valve on this thing. Is there? If not, I figure I need to check valve lash next.

For the two adjustment screws on the carb, I'm assuming 1.5 turns back from fully screwed down is a good starting point, yes?
 

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45psi is pretty low... 50 PSI is what i would call "bare minimum".
could be a valve not closing all the way, as that tends to happen with L head engines, the valve lash gets tighter and can eventually hold a valve open.
 

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Discussion Starter · #3 ·
45psi is pretty low... 50 PSI is what i would call "bare minimum".
could be a valve not closing all the way, as that tends to happen with L head engines, the valve lash gets tighter and can eventually hold a valve open.
If there is not a de-compression valve on this engine, I agree that 45PSI is too low and the most likely suspect is valve lash that's too tight (i.e non-existent even).
 

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Discussion Starter · #5 ·
45psi is pretty low... 50 PSI is what i would call "bare minimum".
could be a valve not closing all the way, as that tends to happen with L head engines, the valve lash gets tighter and can eventually hold a valve open.
Good call. I checked the valve lash - the exhaust was non-existent and the intake was .002". I've never had to grind a valve as much as I did this exhaust valve to get it to .008". Set the intake to .006. Buttoned things back up and checked compression. It was now 60PSI. Could be better, but that should work.

Tried to start it, but no luck. It starts easily with a shot of ether (much easier than before), but immediately dies. So clearly I've got a fueling issue. I thought I got everything cleaned when I took the carb apart, but maybe I missed something? Dunno what else I could try.
 

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there may be 3 holes in in the bowl screw (#15), make sure they are clear, the idle adjustment screw on the side may need tweaked with, (#17), screw it in until fully seated, not tight, just snug, and back it out about 1/4 turn at a time and try to start each time.
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Discussion Starter · #7 ·
there may be 3 holes in in the bowl screw (#15), make sure they are clear,
Good call again! I removed the bowl screw only to find that the small center hole, inset down into the bigger hole, was indeed clogged. I cleared it with the smallest of my jet cleaning tools (pic below), re-assembled, and promptly started the engine! Of course I had to go cut some grass with it at that point - it works great!

Thanks very much for your assistance.

 

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I have a set of brushes like those, they work great!
some people use torch tip cleaners, but the tip cleaners are much more abrasive and rigid than the the carb brushes and if you aren't careful you can take material out and suddenly your engine is running too rich.
 
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