Hi Han,
The smoke you saw initially could have come from oil which was put in the
cylinders when the engine was layed up last season. This will burn off and
cause no problems for future usage. It sounds like you may need a carburator
adjustment, if the engine runs faster in choke mode. Depending
on the outside temperature, an engine may run faster in choke mode, but once it
warms up, it should run better without the choke. Running with the choke on all
the time will probably carbon up your plugs, and is not
advised. Most carburators are set with the choke off and adjusted to the point
of highest rpm with a slight
back off to the leaner position just below that. If after the engine warms up
and you still need the choke to
get it to run at a reasonable rpm, again you probably need an adjustment of the
air/fuel ratio on your carb.

Sherwin Dubren


Han Chung wrote:

Hi,

Before I start, I just want to say that I know next to nothing about
engines.

I have an Australian model Honda HRU196D push mower with a GXV160
engine. The throttle has three positions: low, high and choke.

The first time I started the engine while on choke, a lot of fumes
came out, which I believe is normal. Once the engine was started, I
switched it to "high" and it ran nicely without the smoke. The second
time I used the mower, I put it on choke again and started the engine
but there was almost no smoke, even when the engine was left in choke
mode. When I switched it back to "high", the RPM dropped and it
sounded as though the mower was running on "low" and making less noise
than when it was on choke.

A couple of questions:

1. Does it sound like the cable that connects the throttle may have
come loose, meaning I'm actually unable to get to "choke" mode? In
other words, when the throttle appears to be on "high", I'm in fact
really only on "low"?
It could be a cable problem. Does the engine shut off when you
put it in the 'off' position? If so, I don't suspect the cable.
If you couldn't get to the choke mode, you would have a tough time
starting the engine when it is cold.

2. If the cable hasn't actually come loose, and I am, in fact,
running the mower while on choke all the time, will there be any
damage to the engine?
If in choke all the time, yes.

3. Should the RPM be the same when running on choke and when running
on "high"?
No. When the engine is cold, the choke
should make it run faster. After the engine warms up,
the choke usually makes the engine run slower (assuming the air/fuel
is set properly).

Thanks,

Han.