Oil pump questions - RD125B

[SoCal250]

Working on my 1975 RD125B and came up with some questions regarding the oil pump...

The factory shop manual does not show the same pump as I have, however mine matches what is shown in the Yamaha parts fiche.
- Mine has Part #13, the Cover, Adjust Pulley - part # 402-13146-00-00.
- Under this cover there is what looks like a roll pin, which does not appear in the parts fiche.

Q1) Is the "cover" supposed to be oriented as shown in the photos, with the bent flange in the 9 o'clock position when viewed from the front of the bike?
The fiche shows it straight up at 12:00. I'm guessing the drawing is wrong and the cover is there to keep the pin from falling out.

Q2) It appears that there is a pin extending out under the cover piece. Is that a pressed-in roll pin? Is that supposed to be extending out that far, or should it be pressed into the plunger shaft further?

[SoCal250]

Another question, this one regarding oil pump adjustment...

Q3)  What is Figure 2-21 from the factory service manual supposed to be showing me? 

[Arrow]

The bracket was a vain attempt to stop the roll pin from coming out. It didn't really work and there were two other methods of pulley retention after that.

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[Arrow]

The roll pin is best fitted pushed in. It's quite hard to fit correctly as it must not foul the plunger shaft. I fit the roll pins in a special way, Full diameter all the way through, but they are fitted with a tapered end initially.

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[Striker1423]

The roll pin is best fitted pushed in. It's quite hard to fit correctly as it must not foul the plunger shaft. I fit the roll puns in a special way, Full diameter all the way through, but they are fitted with a tapered end initially.

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Does the roll pin hole go through to the shaft on the RD pumps?

[Arrow]

Yes, its an open ended hole, but the roll pin MUST NOT contact the plunger shaft.

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[Arrow]

As I said, two later subsequent methods for retaining the pulley.

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[Arrow]

Also, the bracket can cause a few issues. I've spoken to people who have the bracket fitted and report zero minimum stroke. The bracket is actually quite soft, if it gets bent down for any reason towards the pulley this can prevent the minimum stroke from occurring, also given that there may be raised marks on the pulley for setting the cable at the closed throttle position, the amount of deflection only needs to be slight.

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[m in sc]

what are your thoughts on tapping the pin hole and using a threaded 'pin' like the later bikes?

[Arrow]

Great, if you can find the size of the thread, and the taps. The screw needs to be the correct part, very fussy on thread length it actually locks off on the shoulder of the screw. You may also have to shorten the pulley itself, in some cases. The screw being bigger diameter than the roll pin moves the pulley a bit further along the boss on the top casting, the pulley can jam just before it gets to fully open.

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[Arrow]

I have 'converted' them before, but I've just used the later type top casting. One of those types comes with its own problems!

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[m in sc]

gotcha. ive done it with a shouldered m3 i think before but was a long time ago as i had a problematic unit on a 74. I do remember having to adjust a few things here and there to get it right.