Hey bulldog, what makes the reel non reversible? Is the pawl not slotted like the last one shown above? Or is it the position of the spring that makes them LHW or RHW?
not sure if that's a question or an answer, but I've converted well over 200 RHW postwar Young reels to LHW. (and the spring tuning I do on RHW or LHW Young reels improves them - Hardy, JAF, FishOn, etc.)http://bulldog1935.u.yuku.com/
if you look at the original hairpin spring check, there are three things that give it a bias. The most obvious is the leverage difference against the spring on opposite sides of the pawl head. In the direction of wind, the pawl is pressing farther out on the spring leaf and has a leverage advantage over the spring. It's especially pronounced on flat-headed pawls, like on the prewar Young shown below.
In pay, the spring gains leverage, since the pawl has to overcome the stiffer side of the spring to allow the drag gear to slip a tooth.
The second factor is less obvious, also leverage, but the fact that the hole/slot in the pawl is asymmetric.
With a round-headed pawl, the spring leverage is not so much a factor, since the round-headed pawl has a small contact patch over the spring regardless of the pawl rotation - in that case, the asymmetry of the pawl slot is the primary source of the leverage difference in wind and pay.
(since you can't see the round-headed pawl beneath a postwar Young stanchion, I'm showing a Hardy)
Simply flipping a pawl often won't allow it to engage at all, to engage too softly, or to not significantly change wind and pay. The third and least obvious thing is the timing of the pawl relative to TDC of the drag gear.
This has to do with the tangent angle of the spring leaf across the head of the pawl - the idea is timing - lead and lag. If you look at the photo just above, the spring has been reshaped to cause the pawl to lead the drag gear in LHW. If it leads too much, it won't engage, and if it lags too much flipping the pawl won't change the tension bias (i.e., wind direction).
I have reshaping postwar Young springs (and Hardy Uniquas, Meeks, etc) down to a science.
Here's a Pridex showing the LHW lead I shoot for.
tougher to see here, but this is my Gilmour with RHW bias and lead
These are automatic for me. I doesn't take me too many spring bends to get both the bias and pay tension I'm shooting for.
I have a calibrated pay flip, and I'm looking to get about 3/4-turn out of my flip in pay.
Once I like it, I set-temper the spring so it will keep.
As far as bending springs, 4" Youngs will break without bending, and are very difficult to replace (though I have a few right now). 3" Young springs are very forgiving , but are also hard to replace, as are the pawls. Garry Mill makes replacement springs (and pawls) for everything in between, and I always have these around. Antique Hardy springs and Dingley springs are brittle high carbon and will not bend without breaking. Also, the pawls on early Hardys and Meek have a shortened head on the back side (relative to wind direction) and will not engage the spring at all if you flip them - for those you need to replace with modern Hardy pawls, and modern Hardy springs, which you can bend.
Bending springs requires the right tools - bending pliers - the sharp corners on other pliers (needle-nose) will break springs. Even then I break a few new Hardy springs when I'm converting reels, and have broken just a few Young springs.
But the point is making the adjustments on springs that are replaceable, not antique springs that can't be replaced (take out your Meek and Uniqua original springs, store them, and use new Hardy springs, etc).
I've done the trial and error, and I'm past art to science, and if you take this up, you'll likely have to go through the same learning curve.
I do provide the service. Do the same thing with both springs in a Beaudex, and also drill and tap to move the line guard using the original (obsolete) BA7 thread
Also do me a favor - if you want to send me reels to work on, I'll be delighted to take them on. But please don't send me essay pm's asking for tutorials.