Small Engines (Lawn Mowers, etc.): Briggs & Stratton points question, briggs stratton, electronic ignition system

Question
My late '80s MTD Yard Machine tiller, with less that 20 actual hours on it, has a B & S engine, model 130202, type 2153-01, date code 87072610.  After Dad passed away, the tiller sat up for a few years with gas in it :-( (my bad), so I had to replace the gas tank and rebuild the carb and put in a new spark plug and air filter.  But, it still won't start or even cough or pop.  Starting fluid, direct through the spark plug hole didn't help either.  I determined the spark is pretty weak by holding the plug wire and pulling the crank rope.  Then, when I attach the wire to the plug (that was removed and grounded), the color of the arc is dull yellow and not brite white.  So, I'm thinking the only thing left is the points, which I assume are behind the flywheel.  Before removing the flywheel and leaving it laying around while I ordered the parts, I went to the exploded parts list for my particular engine at outdoordistributor.com.  They have every screw, washer, gasket and even new decals shown and listed, but they show and list NO points or condenser.  Then, searching the internet, I found a related article that only said "early 1980's B & S engine's had points." which makes me wonder if my late '80s engine has an electronic ignition system, which I would know less than nothing about.  So in defeat, I'm about to load up the tiller and take it to the local small engine repair shop, where I know I'll get hit with a big bill that I can't afford right now, when I discovered your website and started to pray that you can lead me in the path of frugality.  Any suggestions will be warmly received.  Thanks, Butch

Answer
You have a Magntron electronic ignition module, no points.  These modules are pretty reliable, if you see spark they are probably fine...I've only had one module with weak spark...the modules either work or don't work 99.9% of the time.

Since gas sat in the unit for a long time and it will not even try to start with starting fluid I'd suspect a stuck intake valve which would cause low engine compression.

Below is a good link on servicing the valves:

http://engines.myfaqcenter.com/Answer.aspx?p_faqid=3441&body_0$tbKeyword=valve

Before you go pulling of the head you can check the valve movement by removing the valve breather located behind the carb.  You may have to remove the carb to access the valve breather. With the breather removed just pull the starter cord and watch to see if the valves are moving.  While your are there, I'd check the clearance as well.  If the intake valve is stuck I'd try spraying carb cleaning in the spark plug hole and the bottom of the valve inside the valve breather hole.  Let it soak/sit and see if the valve frees up.

Let me know what you find.
Eric