Of mice & man

[kitestrings]

Hadn't run our generator for quite some time.  That's a good thing.  We had good solar production this summer, and very good winds this fall; until now.  I'd fired it up late fall & everything looked and sounded good.  We had family/company over the holiday weekend, and on Monday after a sunless, near windless three day period I reached for the starter switch...

There are sounds that, through experience, you immediately identify.  Some are good, like birds congregating to fly south in the fall.  Others are like when you hear bending metal as your car meets an immovable object.  This one fell in between the extremes... first, the generator cranked, but didn't immediately fire, as normal, then there was a 'ring'.  It's hard to describe, but it was familiar... like a friend from high school you hope to avoid.  And, after attempting once more, when I released the starter, it made the tell-tail back-fire; never does this.

I went out to inspect, and couldn't missed the nesting materials protruding from a few spots.  After removing a small ignition module, I could see (enough) with a flashlight that I had a project ahead of me.  Someone recently said a picture says a thousand words, so here's roughly the sequence...













More in a bit....

[kitestrings]

So, a brief bit of explanation.  The part that needs to be replaced is an ignition rotor.  It is keyed to the crankshaft, and strategically located at the near exact mid-point of this machine... right between the engine section, and the rotor/stator.  It costs about $15.

To get at it is a bit of a puzzle however, and it starts with getting the thing out of a small generator shed on the end of the woodshed, and into the shop.  Briefly:

Turn off the gas (LPG),
disconnect the remote wiring harness,
disconnect the battery,
disconnect the power leads,
disconnect the muffler,
disconnect the gas line,
unbolt the base,
carefully lift above said bolts,
carefully load into trailer,
move to shop


Once there, we begin another sequence:

Drain the oil,
remove the brushes,
remove the cowlings, covers,
remove the air filter housing & carb assy.,
remove the PTO coupling,
remove the retainer and thru-bolt,
remove the base plate

Now it can be tilted onto the blower housing.  It is a tapered-fit, press fit which must be jacked apart.  A small 'parting tool' - mine is a piece of threaded rod with saw kerf in one end - is threaded in, and a larger (1/2" IIRC) bolt is torqued against the end to pop them apart.

Carefully lift, and separate the two halves...   There is the part we're after.  A small keyed piece of plastic with a pencil eraser-sized magnet in each end.  When both halves are there, once per rev, the ignition switches on, and fires the plugs.


The location I suspect is tempting for a mouse.  It sits above the oil reservoir, which stays warm long after the engine has been shut off on a cold fall day.  I'm not sure how to keep them out; clearly.  The entry is where the starter engages the flywheel.  It's very small, but there doesn't seem to be a viable way screen it off.  Making the shed impervious may be a better option, but  sliding door could be a challenge.  I'm open to ideas.

The last time this happened was 2007.  I bought two of them back then.  Maybe that should have been an omen.  My parts supplier, who does RV's said then, "yup, this happens all the time with motor homes (and this generator)."

[kitestrings]

Landed back in the shed.  All good now.


On the right-hand side is the PTO.  We couple the hydraulic pump you can see to the machine for wood splitting in the fall.  Shifting the spacers allows it to hang there de-coupled when not in use.

[MattM]

A distraction perhaps?  Someone makes bucket traps around here.

[Mary B]

Coarse steel wool stuffed in access holes, if it is an area that needs air flow use the coarsest they make and just a thin piece, add it to the filter replacement  schedule because it will collect debris.

glue traps laid end to end all around the generator... not my favorite because the mice suffer

bucket traps, mice fall in and drown, more humane but freeze up  in winter

make a cage of 1/4 inch mesh hardware cloth to surround the generator, most work but once you have it it lasts year after year

A solid box to cover to when not in use, made of metal. Have that possible invasion during cool down time...

[SparWeb]

I don't put water in bucket traps.  I tip them when my dogs are nearby...

About 5 years ago, a strange smell came from my SW4024 inverter as soon as it switched on.  I am VERY lucky I was nearby to notice, rather than run it for long getting hotter and hotter...

[kitestrings]

Some good suggestions here.  Thanks to all.

I'll have to look to see whether the steel wool could work.  My fear is that there are too many points of entry.  And, if it were to loosen and just drawn in, could be a problem.  I was thinking it was only where the starter engages the flywheel, but I'm not sure... there are several voids/vents.

It's an air-cooled engine of course.  It is designed to pull air, starting from the right-hand side as you face it, through the stator, but also thru the fins of the cylinder heads and jugs.  It exhausts this air straight down, and in our case through the floor of the shed.

I like the glue traps, and after this repair could manage to get past any guilt issues ;>]

The bucket trap is simple enough, but I dislike using bait like peanut butter that might attract more visitors (mice, chipmunks, squirrels).

I'm leaning toward a mesh cage, or more concerted effort to rodent proof the shed itself.  It's quite small... so, perhaps a screen door, and plugging the points of entry to the room itself.

The other thought I had was to just get in a regular habit of vacuuming any start of a nest -especially in the fall.  A small flexible rubber hose could probably be slid in there off my shop-vac.

Spar you had some chewed wires too?  Eek! 

[SparWeb]

Yes, you can see many that lost insulation.  That took some work.  The mice were careful enough to pack the wool in so densely to keep the wires separate even as they chewed the insulation off.  Makes you wonder what the mice have learned after all those generations in science labs.

[kitestrings]

Maybe this:
https://www.amazon.com/Catchmaster-Catchzone-1-Roll/dp/B08FBJPWWP

I'm noticing now that it is not by the starter as I'd thought, but more likely at the corners of the cylinder fins, at roughly 10:00 & 2:00, and 4:00 & 8:00 in this picture.  Possibly steel wool can be used there.  There's also a space beside the ignition pick up, but if they can enter there, they probably could squeeze through the intake vents on the stator housing.  It is about the same size.