I am a mechanical engineer and if you have some elementary skills and commonsense it is not always necessary to replace a sticking Mi7 timer.
To repair:
Never work on any electrical appliance without first disconnecting the it from the mains supply. This golden rule applies to the Dualit toaster too.
Remove the timer taking care to note where the wires went, (I find taking a couple of pictures with my phone usually does the trick) How to do this is exactly the same as replacing the timer, you can find instructions all over the www.
The timer has a hexagonal nut around the spigot holding the front cover on; remove this cover to expose a metal housing with a few holes in it.
The timer is probably sticking because over the years the original oil that lubricated the moving parts of the timing mechanism has dried up and become stiff. If this is the case, and we can successfully replace this lubricant then the timer should run normally.
To do this find a small cup and fill it with methylated spirits, put the timer into the meths and let it soak for 30 minutes or so. Keep winding it the timer up and letting it rundown while soaking in the meths, this will help disolve the dried up oil.
Remove the timer and shake all the meths out. Then leave in a warm dry dust free place to completely dry out.
Then using the thin tube attachment on an aerosol of WD40 (or silicon oil if you have it) spray some oil into the holes in the metal front cover. Work the timer and spray a little more. Let the oil soak in.
Now test the timer and see if it runs through without stuttering or stopping. Mine takes 3 min. 10 sec. to rundown to shutoff from the 3 min. setting. In my opinion that’s good enough for a mechanical timer. I tested it 5 times, with identical results which is what we are after.
Should your timer still show vastly different running down times then it’s definitely time to bin it..
If you do decide to try to repair the timer you do so under your own free will, this description is meant as basis for thought and is definitely not in any way a guarantee of a successful repair. Should you decide to apply any of my repair guidelines you do so at your own risk.
ALWAYS REMEMBER: No toaster should ever be left running unattended, no matter what the brand or type of timer, a toaster will always create a fire hazard if the timing mechanism fails. Sods Laws states categorically that they can and will all eventually fail.
In the event of a timer failure the all metal Dualit toasters present a lot less risk than cheaper toasters made with plastic components.
Please use this information responsibly.
martin
October 2012