Sensible engine decision (now top end refresh)

OK. I got three heat cycles on it, then retorqued the head. In addition to the base gasket leaking, the six bolts on the cam chain tensioner were loose. Doh! I drove it about 35 miles. It's very smooth and quiet. I washed it and put it on the lift with paper under it. I hope I'm done with leaks for a while.
I had take one of the carburetors all the way down. The shaft was binding even with the butterfly disk removed. I can't imagine how that happened.

This started when I broke a bolt on the sump plate. I had to split the case to fix that, so I replaced my transmission. Then it got clutch springs, piston rings, and the head was serviced by a machine shop in Memphis. I have brake lines to replace, so I'll get on that as soon as I'm satisfied the engine isn't coming back out. My swingarm bushings are worn out as well. Those bronze bushings I bought from Mike's XS only lasted about 20 years or so.

So, I'm not done, but getting close. I'll try to get a few miles on it over the next couple weeks and torque the head again.
 
jetmechmarty said:
The shaft was binding even with the butterfly disk removed. I can't imagine how that happened.
Click to expand...

The shafts are chromed brass and they bend surprisingly easy. When I rebuilt my XS2 carbs , 2M had suggested that I check them for being true. I chucked them in a cordless drill and could easily see they weren’t straight.

I wrote about it here,
post #280
http://www.xs650.com/threads/mailman’s-xs2-a-full-on-restoration.51520/page-14#post-544351

FD88F2E4-AD18-4E06-8E1B-AB2D26807893.jpeg
 
9B19824B-FE9A-45BA-8777-CBC87AD4ABB8.jpeg


I got almost 100 miles on it. I just dropped the oil. It runs very nice. Cold start is one kick, just like before I went through the carburetors.
The clutch is slipping and it’s pretty bad once I get in 5th gear. I’m hoping that changing the oil will fix it. The friction plates are in spec and I replaced the springs. So, I assume the STP I used as assembly lube is the culprit. I really enjoyed spending an hour on it this afternoon.
 
jetmechmarty said:
View attachment 188486

I got almost 100 miles on it. I just dropped the oil. It runs very nice. Cold start is one kick, just like before I went through the carburetors.
The clutch is slipping and it’s pretty bad once I get in 5th gear. I’m hoping that changing the oil will fix it. The friction plates are in spec and I replaced the springs. So, I assume the STP I used as assembly lube is the culprit. I really enjoyed spending an hour on it this afternoon.
Click to expand...

Congratulations Marty! By the way, you sure do have some pretty riding country where you live!
 
My clutch is still slipping. If at 50 mph in 5th gear, I twist the throttle it breaks loose. To recap, I measured the thickness of the friction plates to assure they're in spec. I replaced the clutch springs with new Vesrah springs. I changed the oil before 100 miles. I readjusted the clutch and the cable according to the Yamaha Service Manual. During engine assembly, I coated the cylinder walls and rings with STP. I did the same to the cam and cylinder head. Is this something that is not going to heal by changing oil? I've got that 20W50 Walmart oil in it right now and that oil has never before been used in this motorcycle.
 
jetmechmarty said:
During engine assembly, I coated the cylinder walls and rings with STP. I did the same to the cam and cylinder head.
Click to expand...
I doubt you added enough STP to cause the slipping you're experiencing Marty. Worst case you could take the clutch apart and soak the plates overnight in Stoddard solvent of some such.... but I'd try some adjusting first.

jetmechmarty said:
I've got that 20W50 Walmart oil in it right now and that oil has never before been used in this motorcycle.
Click to expand...
What does the API label say it has in it? Does the can say motorcycle or wet clutch compatible?
 
Jim said:
What does the API label say it has in it? Does the can say motorcycle or wet clutch compatible?
Click to expand...
API label says SP. The bottom half, where you would look for "Energy Conserving" is blank.

I will go through the adjustment process again and take another ride. I'll put everything else on CDL (can do later.) This nice weather only lasts a few weeks. Too soon it will be too hot to fish (but it's a damp hot.)
 
jetmechmarty said:
I readjusted the clutch and the cable according to the Yamaha Service Manual.
Click to expand...
The manual calls for tightening the perch adjuster all the way in and turning the worm screw back out 1/4 turn after contact. For initial adjustment I bottom the perch adjuster then back it out a turn or so. I'll turn the worm screw until it contacts and then back it off only 1/16 to 1/8th turn. That seems to make for a clutch that gives you adjustment wiggle room while out on the road.
 
I've been using that oil for years without issues so I don't think it's the cause, unless maybe they've changed the formulation recently. I'd give it a few quick changes and see if that helps. After a rebuild, you want to dump the oil within a few hundred miles anyway.

I've never replaced clutch friction plates in one of these because I never found the originals worn out and replacements are costly ($80 to $100). I couldn't see spending all that money on something that wasn't broke, lol. But recently, I did buy some new plates. I found Cruzinimage had plate sets at a reasonable cost (about $30) so I added a set to my last order from them. I haven't tried them yet but I will eventually. Reading on the site here, I guess plates can be bad even though they still measure in spec.
 
5twins said:
Reading on the site here, I guess plates can be bad even though they still measure in spec.
Click to expand...

I had a slipping clutch before teardown. That's why new springs. Now, it's worse.

Jim said:
For initial adjustment I bottom the perch adjuster then back it out a turn or so. I'll turn the worm screw until it contacts and then back it off only 1/16 to 1/8th turn. That seems to make for a clutch that gives you adjustment wiggle room while out on the road.
Click to expand...

I'll follow this, but I'm staying at 1/4 turn for now due to the obvious.
 
I would wait .. Since the plates has been taken out it can take a while before they settle in the basket and so
Oil going in everywhere ..
Basket can have some grooves.
I would adjust if Necessary and as mentioned I adjust via the first gear in --- wheel spinning in the Air.
Foot on the tire clutch in. Stopping the wheel.
Adjusting on the mechanism at the engine case. In this case a bit " Tight "
 
Of course that is personal preferences.
I Know the feeling
But this being a new rebuild experienced man like yourself has not applied torque -- Hot Rodding --Revving ---Quick shifting no real forces gone through or perhaps not even any real heat has been there.
Running in period
After some 200 -- 300 --400 miles Then I would consider opening it If not to severe. Now
And if it is getting better over time I could wait longer .But I am more used with worn bikes
And there is a greater risk things go wrong doing work on them.
In the early days many I knew bought cheap bikes started to open them trying to repair and never again got them out on the road.
You are much more experienced than most doing the work so less risk something goes wrong.
But there is always a risk. Stripping a thread removing the springs or so.
Did you check the steel plates on a glass surface so not a warped one of those. ?
 
Jan_P said:
Did you check the steel plates on a glass surface so not a warped one of those. ?
Click to expand...
I believe I checked that as well, but I'm fuzzy on it.

timbeck said:
Hey Marty---Did you recently replace the clutch cable ??

tim
Click to expand...
I believe I have never replaced the clutch cable. I could have forgotten, but I think this one has over 57,000 miles on it.
 
image.jpg


These are my plugs at about 800 miles. Cold compression test about 150 psi each. My oil capacity remains full. None was added on my 600 mile trip.
image.jpg

After the trip, my fork seals require replacement. It’s not an emergency, but they’re done.

image.jpg

Perhaps I should replace the clutch cable.

Lastly, I have a little play in the swingarm. The bronze bushings I installed about 20 years ago have worn out. I’ll probably take them to a machine shop for removal.

I’m feeling the whole thing has been a success. I look forward to a lot more miles on this machine.
 

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