In article
,
RS at work wrote:

On May 7, 4:50*pm, Joseph Gwinn wrote:
I have a lawnmower and a snowblower, both from Honda, and both are hard
to start at the beginning of their season. *The lawnmower is the worst
offender, by far, so I'll focus on it.

I would always get the mower going, but it could take all day the first
time. *After that initial difficult start, starting was reasonably easy
for the rest of the season.

I have heard various theories on why this is so:

1. *Gas varnished up over the winter. *I took the carb apart - clean as
a whistle. *Nor did gas stabilizer make any difference.

2. *Water (from condensation) in the gas. *Hmm, hard to do with the 10%
alcohol in all gas available these days.

3. Volatiles evaporating from the gas in the tank over the winter. *
Also, various stories saying that winter gas and summer gas are
different, the difference being how volatile the gas is, with winter
needing more volatile gas than summer. *Hmm, this could be at least part
of an answer.

So, this year, when I first tried to start the lawnmower for the summer,
had the usual problems. *Tried the usual dodges, like leaving the mower
out in the sun to warm up, and putting fresh gas in the tank, but no go.

Volatiles? *Ether! *So, I gave it a squirt of starting fluid. *

Started right up on the first try, and subsequent starts were of normal
difficulty, probably because all the old gas was by then flushed out of
the carb.

So, theory 3 seems to be correct.

And a dash of Naptha in the gas may do the same.

. Joe Gwinn

Here is what I found. One of my mowers has a Briggs and Stratton
engine with a plastic diaphram carb and a primer. I have rebuilt the
carb cleaned the tank, changed the plug and the oil and it is a pig to
start cold. Once warm however it restarts easy.

My other two mowers have Tecumseh engines. I added a fuel shut off
valve and an inline filter below the carb to trap any water. With
clean carbs these start cold really well. 5 squirts on the primer and
away she goes. Unless of course I have run it dry then it takes a bit
2-3 attempts to start.

I have had mowers with these engines, and never had any trouble starting
them, so I never needed to become creative.

Although my first Briggs and Stratton was when I was maybe 15, and I
learned about small engines on that mower engine. I didn't fancy going
back to a push mower, and my father was willing to buy any parts I
needed, so that mower got all the repair it needed. I even did valve
jobs on it.


Champion has a new plug out now touted as the "one tug plug" more
resistant to fouling and a more focused spark is the claim. About 2
bucks more than the standard plug, might be worth a try.

This appears to be it:

http://www.federalmogul.com/en/After...merica/Service
Solutions/Products/ChampionSparkPlugs/Lawn-Garden/

Although my problems with starting the Honda have never been solved by
replacing the sparkplug.


One of these days I am going to modify an engine to make the spark
timing adjustable. I suspect that a little more retard on the spark
will make it easier to start, after all it worked on the model T.

At least on the Honda, the advance is adjustable as a repair activity,
so one could certainly retard the spark a bit. But it would stay that
way.


Naptha in the tank would probably make the gas more volatile, but it
would also cause pre-ignition of the fuel and that would be awfully
rough on these little engines with no bearings, so you might need a
start tank and a run tank, not easy if you have a tank mounted carb.

Gasoline already has some naptha in it - the question is how much. There
should be a happy medium.


Joe Gwinn