330 Muffler outlet

[mcycle12]

I was getting a shock through the handle of the 330 yesterday when I was sawing. My gloves were wet and the ground was wet also, which is not normal operating conditions for me or the saw. This may have been going on for a while before I noticed it.

When I took the muffler off to look at the on/off switch, I saw that the wire leading from the ignition module to the switch had about 1" where the insulation was totally gone, leaving the conductor bare. When I looked at it further, I realized that exhaust gases from the muffler were directed back towards the engine. There is a deflector plate behind the muffler that redirects (in theory) the exhaust away from the cylinder and away from the saw. The wires for the on/off switch run directly behind the deflector.

My idea is the excessive heat from this exhaust setup caused the insulation on the wire to deteriorate. I don't know if this is the source of the shock I was feeling, but it may have something to do with a shabby hi-speed running issue that I thought I'd narrowed down to the ignition.

Has anyone else experienced this?

I've seen some of the 330 mufflers that exit directly away from the saw. I did in fact locate one of these of E-bay and promptly purchased it. I'm sure it will be louder, but in my book, keeping all that heat away from the cylinder will outweigh the extra noise.

[sweepleader]

I don't have much to add about the heat, but I do know that the voltage on the kill switch side of an ignition coil can be 200 to 300 volts quite normally. At least with points, and I have to believe it could be with electronic ignition also. Why the kill switch circuit does not give more trouble is beyond me however. Given that most folks, including some ignition engineers, treat it as low voltage, I think it should be a constant source of shocks and shorts. The magnetic field from the high current in the primary of the magneto/coil collapse that causes the spark also causes a voltage spike in the primary, thus the need for the capacitor to prevent the points from arcing. That is the voltage the kill switch circuit has to deal with and the likely source of your tingle.

Your "change the muffler" solution to the wire burning problem seems like a good one.

Thanks for the great picture and description.
Dan

[onlyhomelites]

You probably had one of Homelite's "winter" muffler setups. Some of the saws had optional mufflers designed to heat the engine with exhaust for optimal performance in cold weather. No doubt it contributed to the deterioration of the wires!

[lesorubcheek]

Pretty sure most normal mufflers on 330s had the outlet inside like your's. The parts lists refer to the outer opeining muffler as a "330W" muffler. Not much else to signify a Western version other than a different muffler opening and baffles. Never had one burn through a wire, but not surprized.

Dan

[mcycle12]

I'm happy to report that the new muffler has been installed and saw is running great! The ignition problem seems to have been related to the bare wire, as I suspected. I've got about 5 hours cutting time on it since the repair. All is well. Yes, it is a little louder and I did have to richen up the mixture a bit. I must say that I do enjoy using this saw. I know it may not be one of the most popular models in the Homelite family, but it is the saw I reach for when I want to do some relaxed firewood cutting on medium sized wood.