What's the answer?

[soonerbillz]

Buddy of mine posted this on FB.

"Here's one for the experts. Can anyone spot the difference in these? I'll tell you. The lower one has metal molded in around the shift shaft. No room for a seal like the upper one? We also noticed it was molded really roughly leading us to believe it an early R5 side cover?"

[pdxjim]

Probably a misguided attempt to seal up a leaky shaft 

[m in sc]

i own R5 serial number 2000, so its early. that's not a sign of an early cover.  its modified. I also own a 72. neither have that. Nor have i ever seen it from the factory.

[soonerbillz]

Pretty much agree with all the answers..
But as I know less than nothing.. I ask.

[1976RD400C]

Lookie here.  1973 RD250 (no letter)

[Striker1423]

sooo... why is there an outside seal on the clutch actuator side? makes no sense since the seal is on the motor itself?

[rodneya]

Top one may have been modded to take a bushing to support the shift shaft

[sav0r]

Yeah, a press in bushing there certainly makes way more sense.

[DesmoDrew]

   Some DS7 & R5 & earlyTZ engine side covers have the recessed area some don't.  Not sure of the years with either.  I have some of each.  It is not for a rubber seal.  It was for a felt 'washer' dust seal.  Just like the on in the rear arm for the drum brake. 


Felt washer is shown with the shift mechanism.

https://www.cmsnl.com/yamaha-r5b-1971-usa_model8371/partslist/C-03.html#.YdEMES-B1QI

US sites list the part, but CMSL shows pictures of the individual parts.

[m in sc]

fuck.. you know, now that you mention it, i do remember seeing the felt washer on some.

interestingly, the part number is the same for all 3 years r5 and the ds7. and the fiche shows the recess. But i have a stak of them and none have it. weird. but drew is right, i have seen that before.

COVER, CRANKCASE L 278-15411-00-00

https://www.shopyamaha.com/parts-catalog/parts/star-mcy?ls=Star&nw=yamaha-motor-company&dealernumber=#/Yamaha/R5_-_1970/CRANKCASE_COVER

[DesmoDrew]

   I also have some DS7/R5 Clutch side covers which have the 'boss' for the optional Right side shift.  Some are not drilled out or machined for the seal, and some are machined but have a solid rubber seal in place (same seal as the shift fork rods use on the left side).  Both are original from the factory that way. 

[m in sc]

that ive seen, have a few actually .

[m in sc]

as a follow up, was working on barney today a bit and looked ad the engine covers, they are both original tot he bike and lo and behold has both the pocketed LH one (hard to see in pic but its there) AND the plugged shift shaft RH one.  I also know this bike was built in (late) 69
however, the ds7 has neither

[soonerbillz]

So I'll assume that we really don't know when or why Yamaha made or installed these different cases.
No rhyme or reason?

[m in sc]

id say 1970 and some crept into 71 as leftover parts. neither 72s i have have them, nor did the 71 i had but it was a later 71.