Well, I’ve been using this Flymo for over a year now. I’m still pretty enamored with its oddity.
However, after a year back in use after who knows how long of sitting on a shelf, I have come to a couple of maintenance issues that I’m hoping the bottomless expertise that exists on the site can help me with.
I still love this tiny engine. 3.5 hp Tec*mseh 2-stroke in aluminum. I still have not managed to find grass thick enough to stall it. Part of that might be that the deck is a bit deeper than a standard mower, which limits a bit how much vegetation gets up in there if the grass is really long. Part of it may also be that there is no lift whatsoever to the blades, so they just cut through a cloud of grass clippings with less resistance like a knife. Generally, the thicker the grass is, the happier it is.
However, I have had a few foibles.
I mentioned I had a bolt hole stripped that held the cover on. There are three bolts. One hole stripped. One bolt vibrated out and got lost. The last remaining one snapped off part of the casting, since it was the only remaining thing holding the engine cover (and therefore the fuel tank) on.
Good news. The bolts only engaged some of the threads that were already present. Therefore, there are intact threads beyond the area where they were stripped. I got longer bolts and did a trick I’ve often seen mentioned here on the forum: cut a lengthwise slot in the bolt threads to use a bolt like a tap in order to clean out the spooge from the extra threads. Worked great! All 3 bolts hold securely now, though I will probably end up using an insert on the partially stripped one eventually. Or maybe just a nut on the back side of the bolt?
The part of the casting that broke out around the bolt hole was partially weathered, so the fatigue crack has clearly been growing for some time. I thought about brazing it, but wasn’t sure I could get it hot enough to do so successfully with the small oxy-MAPP torch I have. Instead, I fell back on everyone’s favorite, JB weld, using a couple pieces of 1/2” flat aluminum stock I had laying around to back up the epoxied joints for added strength. I think that’s going to work out well, though it looks ugly as all get out. At least it will be hidden.
One interesting thing about this engine. That white flag-looking thing? That’s the governor. No heavy governor weights to hold this thing down. That vane moves in the breeze from the flywheel fan, and the strength of that breeze is how it knows how fast the engine is spinning. Pretty innovative way to save a couple ounces. It works really seamlessly.
The fuel tank had originally been held down by a pair of screws to the engine cover. The holes were threaded, but just in thin sheet metal, so they were not holding that well. I ended up losing both screws. As a fix, I JB Welded two machine screws under the engine cover, sticking up like studs. Now I need to get a small bushing to protect the plastic tank from the screw threads and lock nuts, because I can’t tighten these enough against the plastic to keep them from vibrating loose. Or maybe just slipping an o-ring over the screw after the nut would be enough to keep it in place?
Ok, now the bits I need guidance on. The spark plug wire gets jammed between two cooling fins on the head in order to pass out from under the engine cover. During the couple times I ran this while the cover was inadequately fastened, the plug wire shifted and got pinched between a short fin and the cover, cutting the plug wire insulation in a couple spots. I can’t get this to run now, and I believe it is because I am grounding out the plug wire through this damaged insulation. I tried several wraps of electrical tape, which seemed to work for maybe a couple minutes. I gather electrical tape is only good for about 600V, and a plug wire can see maybe 10,000V? There is not physically enough room for enough layers of tape to get sufficient protection that way.
So, question 1, does anyone have a better idea for repairing the insulation on the plug wire?
Or, question 2, does anyone know how to get the plug wire out of the magneto without damage so I can replace just the wire, without having to source a new magneto for a 45 year old lawn mower? I’m thinking just cut as best I can through the sealant or epoxy around the wire, and just pull? Not sure if the white thing is some sort of retaining clip that I would need to deal with in some fashion?
While trying to troubleshoot spark in the no-start situation, I did get a decent poke off the spark plug boot. So I know there is at least some spark being produced, I just don’t think it’s going where it needs to.
Secondly, while trying to troubleshoot the spark issue, the rope on the recoil starter gave out.
I believe I have to disassemble the recoil unit to swap out the rope, but I haven’t figured out how to get into it. I think the only way in is to press out the axle to let everything slide out of the holder, but it doesn’t want to budge. The body of the recoil unit is all one piece, and does not come apart. Everything is plastic to save weight, and 45 years old. I don’t want to break anything. I don’t think it’s just a matter of bending the holder enough to pop out the gear and spring. I’m pretty positive that would require more deflection than it would survive, even when new.
It could use some grease inside, but otherwise it’s still in remarkably good shape. This I probably could find a replacement for, but that replacement would probably have a rope just as old. Does anyone have any ideas how to get into this?
I guess, short term, I can just reattach the handle to the existing rope. I will only have lost about 6”, and it will get by for a little while at least.
