I had a problem where the engine would die when set at half-choke and
the throttle was advanced. (Could be advanced a little without dying
but not full.) At no choke the engine would not run at all. I tried
adjusting the jets to no avail-
I purchased a Zama rebuild kit. When installing, the carb looked
extremely clean and no parts appeared damaged or worn. I did not soak
the carb at all, maybe a bad idea.
On reassembly the engine runs better but not perfectly. It now
runs fairly fast at no choke, but still runs better at half. It wants
to go to full throttle at half choke but then seems to run unevenly
and slower. Oddly, when then moved to no choke the rpms increase to
almost full throttle but then go back down again.
Three options to do next:
(1) Take the carb off again, re-disassemble and soak.
(2) Assume the tank strainer has a problem (what to do if it's
(3) Assume the gas is bad and replace. (Gas is LT 6mo old.)
What would you do *first*?
Thanks for help!
I'd put Permatex IIb non hardening on both sides of the gasket betwen the
carb and the machine. I've had a leaky gasket do that, more than once. When
that happens, the machine draws air after the carb, and runs lean.
Hmmm...I had actually thought of that- should have been option 4.
Will give it a shot. Thanks.
The fact that when reassembled there was a slight improvement
also supports your idea because I think the carb kit did nothing.
BTW how likely is it ever that the strainer in the bottom of the
fuel tank gets partially plugged? And how often does an overhaul kit
improve things? Nothing I saw in the kit looks like it could go bad
except possible the diaphragm, and while mine looked a *little* floppy
I doubt that would cause problems.
On Thu, 15 Dec 2011 17:22:56 -0500, "Stormin Mormon"
In my experience rebuilding carbs the problem is almost always dirt in a
jet or orifice or somewhere, I seldom buy a rebuild kit and often make
new gaskets myself. Not very often do they need any new parts.
Y'welcome. Just sharing what I have learned. I'm sure some mower repair guys
are cursing me for costing them a repair call. Ah, well. It's the economy.
Strainers do get plugged. How often? I don't know. If yours is a two stroke,
with flexible gas line. you will need a bent wire with a hook on the end, to
get the hose to come out, and let you get at the intake filter. Filter
probably has weight built into it, to keep the pickup down into the fuel.
Best of luck, please let us know how it works out.
Christopher A. Young
Learn more about Jesus
Why are you rebuilding the carb? What diagnostic tests lead you to
suspect the carb? Have you checked for vacuum leaks? It sounds like you're
Get a can of carb cleaner. Start the engine and let it run for a minute
or two. Spray carb cleaner where the carb bolts to the head. Does the engine
stumble? If yes, then fix the leak. Spray the head gasket. Did the engine
stumble? Et c.
I doubt that you have bad gas or a bad filter but these are easy to
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