I have a grade 240 Elgin that ran great except for it lost a couple minutes at the end of each winding. I got into it and found that it had the wrong mainspring in it. Somebody had modified a generic MS to work in the barrel. Now, I have replaced the MS with the correct Elgin nos and the watch runs fast. It will gain about ten minutes per day. Any suggestions?

Aaron
Casual junk collector

We have lots of good people here to help us with watch problems.I did however find a site that has alot of good watch info on it.One of the topics there is watches gaining time.
Site is Carignan Watch Repair Company, Inc.
They have some really great diagrams there too.

Kevin "Veritas" West

Did some checking with the watch. All the ballance weights are there. Does this model use meantime screws? If so they are not there. The hairspring is not oily, bent or rubbing on anything. The ballance is running true. The hairspring is flat nd the overcoil looks okat and clear or obstruction. Could magnetism cause this? If I ran it through a demagnetiser and did it wrong could this cause a problem?

I am thinking that whoever changed the mainspring to the wrong one took weight off the ballance to compensate for the weaker mainspring. Could this have happend? The mainspring I took out of it was dementionally the same but was wrong and set anyway.

BTW as a side note the escapement is not "knocking that banking" in any positions.

Aaron
Casual junk collector

Aaron,

Is this the 240 you put the new mainspring in last Saturday? When was the watch last serviced, properly? Before any timing adjustments are made, I recommend a teardown, parts inspection, clean and lube. Now you have a good baseline to start with.

John D. Duvall
Vice President, Education

Good advice John.
Aaron, I think you may be right. Whoever put in the mainspring, may have set it up for that spring.

pwpartsetc@pwatch.com

John,

Thats the watch. I'll give it a good cleaning and oil and go from there. It may be a little while though.
Thanks,

Aaron
Casual junk collector

Brian,

That's a cool looking avatar.

John D. Duvall
Vice President, Education

Yes it is John. My good friend John Duvall help me with it.
Brian C.

pwpartsetc@pwatch.com

Aaron,

The cleaning would be the best track. Also check the staff for either flat or mis-shapen pivot ends. These can effect the arc of motion of the balance wheel. Short (abreviated) arc can cause a watch to gain time.

Mike Miller

While juse putting an eyeball on this thing I did notice the little slots on the cap jewel on the ballance bridge are not in line with the screws. Could this be a sign of a problem?

Aaron
Casual junk collector