Timing chain jump tooth

ekestle

XS650 Enthusiast
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Hi bike in the shop pulling top half to line the chain back up. Wondering if the shop should replace the chain and does it have to be a endless chain? Anything else you would do while they have the engine pulled?
 
I highly doubt the chain jumped a tooth. It took everything to put mine on with washers and nuts secured thr head down far enough to put the link and set in place. Maybe if the cam chain adjuster was all the way out....
 
If the chain did jump a tooth, that would indicate it was very stretched out, and I would replace it. No, you don't need or normally use an endless chain, the factory didn't. You can, but that involves much more teardown. The bottom end has to come all apart so that endless chain can be slipped over the end of the crank. Normally, any 1st time teardown I do on one of these gets a new chain, unless maybe the motor is very, very low mileage (5K maybe).
 
Thanks for the reply. Not many in my area know anything about these old XS1. It has been sitting for 20 years when I got it. I could not get it in time. I even drilled the points plate to get close and then the timing is still retarded. I know someone previous has messed with the timing because the cover looks like it was taken off with channel locks. It has 9000 miles wouldn't think it would be stretched. I don't know very frustrated and that was the only other thing that I knew and the shop that is working on it.
 
Running out of timing plate adjustment is a sign that the cam chain could be badly stretched out, or has jumped a tooth. But as mentioned, a new chain is very tight and probably couldn't jump a tooth. Even a slightly used one probably wouldn't be loose enough to jump a tooth. Only 9K miles but were they hard miles with no care and maintenance? Unfortunately, that's how many of these got treated. I guess you'll know when the shop pops the top off and checks the cam timing. Be aware that if you do need a new chain, your early model uses a different one than the '74 and newer motors. It has a different pitch and length.
 
Thanks 5twins! Wish you were closer sure would pick your brain! I think I will buy a NOS chain and link on E-bay. Along with the front chain guide. The early model 102. Can't hurt to have a spare even if I don't use it. The owner of the shop told me that installing a new chain thru the bottom and using a master link wasn't the right way. I don't see a problem with it.
 
Your "shop guy" is clueless, at least when it comes to XS650's. The factory used a split chain with a riveted master link. Usually, you install the new chain from the top. You hook one end to an end of the old chain, pull the old one out and the new one in along with it.
 
Early XS units has a web between the cylinders... which means the chain has to be opened to remove the cylinders..later units had a open slot between the cylinders.. lift the cylinders off... hook the replacement chain to the old chain and slowly roll it around.... Mike's has a punch tool to mount the new chain link.. I used a large set of bolt cutters..
 
Yes, Mike's does have the riveting tool but they charge an arm and a leg for it. You can find pretty much the same tool on eBay for much cheaper.
 
Some people get stumped when ordering new chains, as most will say "endless". Those are fine to order (just in the event you are concerned about it). You simply take a dremel and grind off the ends of one of the links, pop it out, and then when re-assembling use a master link and rivet that back on. Do a search and you'll find different ways guys have "rivited" the master link, including using a punch with a large hammer as a backing plate. A riveting tool is the "right" way of doing it, but not absolutely necessary. Take a look at the tech section, Top End Build Buildup thread by JimD....very helpful! http://www.xs650.com/threads/xs650-top-end-buildup.52041/
 
My "new" chain riveter broke upon removing one of the links. I simply peened the master link in place using a large hammer head to one side and punch on the other. Finished off by rounding the head of the rivet with a ball peen hammer. Ohh btw, the chain comes with a master link...XS 650 direct got me for another $5.95 :(:(
 
Hi bike in the shop pulling top half to line the chain back up. Wondering if the shop should replace the chain and does it have to be a endless chain? Anything else you would do while they have the engine pulled?
You don't have to pull the engine apart to check the valve timing, it can be done with a dial indicator. Pull the gas tank off(makes things handier) and the intake/exhaust tappet covers on the left cylinder. Mount the dial indicator so it touches the top of the intake valve spring keeper(valve closed) and zero the dial reading. Turn the engine forward, the dial will move as the valve opens and closes, stop at the TDC mark on the exhaust stroke. The valve will be opened slightly, write down the reading on the dial. Move the dial indicator to the exhaust side and repeat. If the cam timing is correct, both readings should be the same(or very nearly so). Sounds like a lot of work but it actually takes no more time that adjusting the valves. You can pick up a cheap dial indicator and a magnetic base for it at a place like Harbor Freight for less than the cost of one hour's shop time.
 
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