100 miles on 1981 XS650 continued: Cotter Pin on Axle? Please Help.

Smorg

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So this is my 1st Yamaha. I got it with 1080 miles a month ago, looking brand new. I now have 1900 miles on it, and I broke my hip right before I bought the bike and still put on the 900 miles! I have owned four Hondas including 3 Nighthawk's, ( 250,450,& 750), and a CX500. I have also had Suzuki GS450. All the Honda's came with tool kits under the rear tire. Neither the Honda's or the Suzuki had a pin in the rear axle. It looks weird. Never seen anything like it in my experience or life!! My chain is loose and needs to be adjusted for me to ride safely. Do I loosen both sides of the wheel/alxe or just one? Do I remove the cotter pin. Adjusting the brakes looks like on every other bike I have owned. Removing the rear axle? On the Right side of the bike is a disc with a hole on the edge. I have done carbs, replaced petcock's, fuse boxes, cables and the like on the other bikes but their manuals were legible and they came with tools. The one posted on this sight just says-

2. Tension adjustment
a. Loosen the rear brake adjuster.
b. Remove the cotter pin of the rear wheel
axle nut.
c. Loosen the rear wheel axle nut.


So I think I loosen up the left side only. If anyone wishes to advise I'd appreciate it. Do you reuse your cotter pin? is it required to have it?

On all my other bikes you just put it up on the center stand, unlocked just the nut on the right side so the rear tire can travel, loosen the adjustor lock nuts holding the chain adjustor on each side, tighten the chain equally on each side, tighten the chain adjustor lock nuts nuts, tighten the wheel/axle. then sit on the bike to be sure it is still adjusted right. Any advise or link to a video would be very appreciated.
 
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Hmmm.......I maybe deciphered all that, but pics would lead me to a more confident answer (both sides with parts in question please).
 
Looking at the bike from the rear.
Remove cotter pin and set aside.
Use appropriate spanner’s / sockets that fit both the nut on the left and axle bolt head on the right.
Hold bolt head steady and undo the nut.
Loosen lock nuts on adjusters. Use the two chain tension adjusters on the ends of the swing arm to tighten up chain. You should rotate chain on sprockets to find the part of it under most tension first. Do not make chain too taught. Evenly adjust using markers on swing arm.
Retighten adjusting nuts.
Retighten axle nut to handbook specification. Or FT if you don’t know.
Line up axle nut with hole in axle and insert a new cotter pin.

This is such a simple job (similar on all older bikes I have owned).
If you cant work this out go to a bike mechanic for SAFETY SAKE.
 
Left and right as a stock 81 would be

left rear.jpg right rear.jpg
Remove cotter pin. Most if not all rear axles pin the nut with a cotter key.
Loosen nut, 27mm, slip a screw driver in hole through axle head to hold it from turning if necessary
loosen both jam nuts on axle adjusters.
tighten both adjusters equally. til about 3/4" of up to down mid chain at tightest spot. The adjusters should each have scribed line above the axle they should both be at the same distance back measured by the raised lines on the swing arm..
Inspect sprockets for excessive wear. attempt to pull chain away from sprocket at the back if you can see tip of sprocket tooth from the side chain is worn out.
Retighten the nut "Good and tight" then enough to align a nut slot with an axle hole, reinstall cotter pin..
check rear brake action adjust as needed with nut (parts missing in my RH pic).
If your parts don't look like these parts we need to see pics.
 
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Left and right as a stock 81 would be

View attachment 224857 View attachment 224856
Remove cotter pin. Most if not all rear axles pin the nut with a cotter key.
Loosen nut, 27mm, slip a screw driver in hole through axle head to hold it from turning if necessary
loosen both jam nuts on axle adjusters.
tighten both adjusters equally. til about 3/4" of up to down mid chain at tightest spot. The adjusters should each have scribed line above the axle they should both be at the same distance back measured by the raised lines on the swing arm..
Inspect sprockets for excessive wear. attempt to pull chain away from sprocket at the back if you can see tip of sprocket tooth from the side chain is worn out.
Retighten the nut "Good and tight" then enough to align a nut slot with an axle hole, reinstall cotter pin..
check rear brake action adjust as needed with nut (parts missing in my RH pic).
If your parts don't look like these parts we need to see pics.
Thank you so much sir. I was wondering what to do with the cotter pin and what the purpose of the hole in the axle head were for. I got it from there. Lots different under the seat than the NIghthawks were. Will post more photos. Still haven't washed. When I say original I mean chain, tires, and everything.
 
What's A&E? I was going to replace the tires as part of purchasing the bike but I have changed my mind. I have read all about how even if they aren't cracked they would be stiff from being so old, and would never perform like a new tire.. I found out about the bike because I gave some Catfish to the owner of a Harley Repair/Sales shop next to the bar where my girlfriend has worked for 20+ years. While sharing about his Stepfather who was passing away on life support and his upcoming responsibilities (stuff I had been through in recent years) he says "hey you like those little Jap bikes don't you! Dad has one been in his bedroom for like 30 years. He pushed it up there through the porch and it's been there all this time" So I was going to buy new tires but they look like new. He was like "I'll sell you tires, happily if you like but honestly, those look fine." They aren't dry-rotted or cracked at all. I won't be riding in the rain, or cornering hard on gravel, but I'll probably finish the season on these. I have already had the speedo buried more times than I can count. It only goes to 85mph but I ran it at over 6500 rpm for minutes in 5th gear including down a big hill so I'm pretty sure I have hit the Ton. it does get a little squirrley at over 85 and I don't want to blow up my older bike so I try to keep it under 80.
 
Your life, your medical bills. REALLY inspect those tires. check for cracks in sidewalls, between tread blocks.
 
Can the cotter pin be re-used? I did inspect the tires. I already have been in an accident where a car pulled in front of me and I was launched 50 yards off a bike labor day weekend 2015.
I Pad photos 060.JPG
 
Well I'm cheap and tend to straighten and reuse cotter pins a time or two. Usually just put a bit of a bend on one leg when installingfor easier removal reuse.
But hitch pins clips are handy for axles too.
1663164134157.png
 
What's A&E? I was going to replace the tires as part of purchasing the bike but I have changed my mind. I have read all about how even if they aren't cracked they would be stiff from being so old, and would never perform like a new tire.. I found out about the bike because I gave some Catfish to the owner of a Harley Repair/Sales shop next to the bar where my girlfriend has worked for 20+ years. While sharing about his Stepfather who was passing away on life support and his upcoming responsibilities (stuff I had been through in recent years) he says "hey you like those little Jap bikes don't you! Dad has one been in his bedroom for like 30 years. He pushed it up there through the porch and it's been there all this time" So I was going to buy new tires but they look like new. He was like "I'll sell you tires, happily if you like but honestly, those look fine." They aren't dry-rotted or cracked at all. I won't be riding in the rain, or cornering hard on gravel, but I'll probably finish the season on these. I have already had the speedo buried more times than I can count. It only goes to 85mph but I ran it at over 6500 rpm for minutes in 5th gear including down a big hill so I'm pretty sure I have hit the Ton. it does get a little squirrley at over 85 and I don't want to blow up my older bike so I try to keep it under 80.
Even if the tires are looking OK with no visible wear or cracks etc; the chemical make up will have deteriorated over the years. The rubber will have hardened and grip, even in the dry, will be compromised. Its a one way trip to A&E (Accident & Emergency) if you use them. They will just let go without warning; ask me how I know!
 
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