mar clutch

[deputy dawg]

Bit of a stupid question, but when you put the nut securing wire on the mar clutch, do you route the wire through all 5 posts or wire them individually 

[stan wellback]

when I bought my first one brand new in 1974 it had individual split pins, not wire.

I don't bother with anything, not had one come loose, but bound to get replies saying different now.

[pmk]

I locwired single strand through all holes.  I can post a photo later when I am on the laptop.

[pmk]

The photo shows how the locwire was used to single strand the 5 safeties. 

The studs are welded into the inner clutch basket, so while not normally positioned in the way I did the wire, even though the wire appears to pull to loosen, the studs will not rotate.  The wire is simply ensuring the slotted nuts do not unwind.  The wire laid down best as shown for my clutch.  Depending upon how the stud holes are in a different basket, it may lay better in a pull towards CW direction.

Ensure you do not pull the wire fully tight, the cups the springs are inserted into will raise and fall as the clutch is used.  If the wire is drawn tight, it could break.

[deputy dawg]

Thank you for the replies much clearer now think i also need to tighten the nuts a little more looking at the picture mine aren't through very far.

[stan wellback]

19 hours ago, pmk said:

The photo shows how the locwire was used to single strand the 5 safeties. 

The studs are welded into the inner clutch basket, so while not normally positioned in the way I did the wire, even though the wire appears to pull to loosen, the studs will not rotate.  The wire is simply ensuring the slotted nuts do not unwind.  The wire laid down best as shown for my clutch.  Depending upon how the stud holes are in a different basket, it may lay better in a pull towards CW direction.

Ensure you do not pull the wire fully tight, the cups the springs are inserted into will raise and fall as the clutch is used.  If the wire is drawn tight, it could break.

damn, thats ugly!!

[pmk]

4 hours ago, stan wellback said:

damn, thats ugly!!

Should I redo it?

[lotus54]

Every vintage OSSA I've seen has Cotter pins (split pins) there each individually. Safety wire might be easier, but I would probably just fit the cotter pins again.

[pmk]

OSSA stuff is new to me.  Japanese and KTMs, even Maicos I have worked on before.

When I got this MAR of mine, I started researching and reading.

What I did notice was that the guy that wrote the manual almost seemed to have been or was an aircraft technician.  Many of the words and phrases had me thinking I was at work repairing an aircraft.

Oddly, I agree, non of the three OSSA MAR motors I have disassembled had locwire.  Two had cotter keys and one had nothing.

The manual though, did say to use either cotter keys or safety wire.  I have rolls of lockwire, less expensive, easier to do, and few bits to accidentally drop into the gearbox.  That was the reason I chose that route.

From a safety standpoint, not that we as moto riders ever concern ourselves with safety, fewer sharp pointy edges to remove fingerprints.

Edited June 5, 2017 by pmk

[pmk]

Lotus54, thank you for getting me to look that info up.  I learned one more of the quirky things about OSSA motors.

Apparently, they use three different clutch plates.  All the fibers are the same.  However, while the steel driven plates appear the same, one plate is thicker according to the manual.  I did not notice or remember reading that, so, I'll pull the clutch plates out and see.  I expect the manual is correct.

Not difficult, just one more thing.

[woody]

Thicker drive plate goes on the inside of the basket.

Only personal choice but I've never wired the spring screws and never had them come loose.

[pmk]

2 hours ago, woody said:

Thicker drive plate goes on the inside of the basket.

Only personal choice but I've never wired the spring screws and never had them come loose.

Yes, was not aware and did not suspect one oddball clutch plate that retained the good looks of the others.

Correct it is the first plate in the entire basket and supports the rest of them.

Not a big deal to check, and won't happen to me again.

So many little quirky things to learn, certainly have been spoiled by Japanese stuff.

[pmk]

If it helps, the thicker steel plate that goes into the clutch first is 2mm thick.  The remainder of the steel plates are 1 1/2mm thick.

Visually, other than thickness, they are indentical as best I could tell.

Simple to correct, and now proper.