[SEL] Engine problems

[JIM KIRKES]

About 4 or 5 years ago I took a Alamo flywheel engine to a 
show.  This engine has always been easy to start and a good 
runner.  It refused to run and I did some  show fixing but 
finally gave it up and brought it home and let it sit until 
now.  I decided to take it to an upcoming show and did not 
want to repeat the previous fiasco so I wheeled it into the 
shop and began to fiddle with it.  I got it started and 
convinced myself it was not getting a good fuel supply.  I 
took the fuel pump apart and made sure the check valves 
worked and put it back together with almost no change except 
maybe worse.  Well the next thing was to take the mixer 
apart, when in doubt take something apart, at the very least 
find something to twist.  This is an overflow mixer and 
there really is not much in it to go  wrong,  made sure 
everything was clear and put it back on the engine. I also 
took the mag/igniter out and checked the spark and it  made 
a nice fat blue spark. I got the engine started after some 
backfires and flooding which kind of surprised me as it 
never did this before. The engine was running but rather 
poorly and sometimes hitting the mag trip 4 or 5 times 
before firing.  I was a little perplexed, after all there is 
a pretty definite limit to what can be fixed on an engine 
like this. After watching this bad runner for a while it 
looked like the mag was not getting a very good trip.  I 
held the trip down with my finger so as to get more rotation 
on the mag armature and the everything smoothed right out. 
I took the trip off and reworked it so as to have a longer 
engagement and get a faster and longer rotation of the 
armature.  Problem solved, runs fine.

A mag works by turning the armature through the magnetic 
field.  The hottest spark will be produced by turning 
through the most lines of force as fast as possible.  The 
mag trip on this engine was one of those thing that wear 
very slowly until it finally does not work very well.  As 
this happens over a long time it can be hard to spot. The 
mag worked fine outside the engine with the hand trip.The 
hand trip never gets used so it works pretty much like it 
did when it was new which got me convinced that there was 
nothing wrong with it. Amazing how you can look at something 
you understand and see nothing until it finally beats you 
over the head.  The upside of all this is that it runs like 
it used to and I know the fuel system is clean.

Jim

Jim and Diane Kirkes
Hemet, California U.S.A.
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jd.kirkes at verizon.nomore