Bulova 386-G loose bezel and other questions

Submitted by PIkyle on February 8, 2021 - 12:34pm

Hi All,


recent forum member here, I picked up a 386-G recently and really like it. It has a few issues I'd like to resolve. Firstly, the rotating bezel is loose enough that it turns when I wind the watch. It isn't loose enough to pop off without a tool but I'd like to have it tighter. I dug through a few posts and found that Reverend Rob mentioned using a rolex bezel spring. I was hoping to get a part number for this or dimensions.  Secondly, the second hand occasionally lags then jumps when the watch is held in certain positions. Again, reading it seems like it could be the spring which supplies tension to the second hand may be weak? Finally, the watch runs about 20 seconds slow a day- is this within the specs that a decent clean would likely fix? I know it's hard to answer questions on a watch you haven't seen. Any input is much appreciated


Thanks Much


Posted February 9, 2021 - 5:20pm

What is a 386-G?

Is there a case model number in the back of the watch?

Posted February 10, 2021 - 12:02am

A bulova snorkel with the white dial. I haven't had the back off, don't have the correct tool and do not want to damage it. 

Bulova face

Reverend Rob
Posted February 12, 2021 - 2:31am

I remember the issue, yes, I used a flat Rolex spring that I happened to have handy. It was a fluke that it fit or even worked properly. I couldn't tell you what the part number was. Pretty much any spacer type spring/ring will work if it is the right size. We're talking something fairly thin, here.

Stuttering sweep second hands are corrected by careful adjustment of the tension of the spring that sits on top of them, almost like a crooked finger pressing down on the polished top of the sweep pinion.

The top is oiled with very light oil, usually Moebius 9010, and the tension is critical. Too little and the sweep hand will stutter, too much and the sweep drags on the power. You can see this if you check it with a timing machine after adjustment, the amplitude will be lessened. Less commonly, stuttering can be the result of a loose sweep driving wheel. After many removals and re-installations, the driving wheel may not fit tightly enough on the extended 3rd wheel arbor. The wheel must then be carefully tightened using a small round nose punch in a staking tool. Care must be taken not to hit it too hard, it is a small part and easily destroyed. If you've never done it before, I recommend seeing a qualified watchmaker. As I mentioned, this is the less likely of the two causes.

Reverend Rob
Posted February 12, 2021 - 2:40am

I missed that last part- If the watch has an unknown service history, chances are it has not been serviced recently. I'd say 99% or more of the watches I see either have never been serviced or are significantly overdue for one.

Dirt and dried out lubricants can and do cause rapid wear and tear to parts, and we are taught to service a watch before regulation. The watch must be scrupulously clean and properly oiled to do a decent regulation job. You can't oil a dirty watch, it will just allow the dirt to collect right where it will do the most harm. 

With the watch clean and all issues rectified (like the tension in the sweep) you can then regulate the watch. For these types, three position timing is adequate, and more than likely the hairspring will need adjustment, and possibly the beat error. I caution anyone that even touching a hairspring can ruin it, so once again, please see a watchmaker. The beat error on older watches without movable stud carriers is corrected statically, by removing the balance from the balance bridge and turning the collet of the hairspring with a special tool. You then have to re-assemble the balance and check the beat error. This can take multiple adjustments to get within tolerance. Ideal beat error is 0.00, obviously, but around 1 to 3 ms is acceptable in an old watch. 

I should also mention that prior to regulation and adjustments, the watch is equipped with a new mainspring. This will make the adjusting easier. A watch with a worn out mainspring has low amplitude, and it is impossible to regulate properly. Mainsprings are the most common replaced part during service. 

Posted February 12, 2021 - 10:54am

Thank you very much for your detailed answer! Yep, adjustments like this are beyond any skills I have!