Cam chain replacement without splittin' her......

So far I have read on a couple of various threads on this site about the possibility of replacing the cam chain without splitting the case. I have yet to find a post that details it any better than my first sentence though. Haha. Yeah, I got tired of looking too so just posted.

I am also like some of the other posters, getting chain slap against the top of my valve cover and my automatic tensioner is just not keeping up anymore. Plus I can hear the damn thing when I ride now, so I is just bother the bejezus out of me. Upon removing the valve cover I started with valve adjustment also. The PO set the valves way to tight as I am not able to get any of my feeler guages through 5 of the valves upon checking, so I figure now will be a good time to take care of that too. Package deal, hopefully.

I understand (in theory) on how to split/break the old chain and attach the new one. But I am not understanding how to keep everything from moving in the process of rotating the new chain through the bottom sprocket and back up so I don't get off 1 tooth on the top or bottom sprocket. Unless I am reading my Haynes manual wrong, doesn't a person still have to get the cams out to set the timing on them, or does everything miraculously stay put and not move. I think I know how to reset the bottom with the T mark on the left crank side...ok now I am confused again...

Don't get me wrong, I hope this is easier than I am making it sound. I am just hoping someone has done this before and can offer some "more" help to us newcomers.... You guys have been soooo helpful in the past. From diagnostics to cleaning..I have been able to usually find it here. Wanted you all to know that too.

Thanx again

Dustin

 

Pull plugs.

Do yer shims.

Break the chain. Hook end of new chain to end of old chain.

Turn engine carefully, keeping everything tight so cams move with engine (probably need helper). As the old chain feeds through engine it will pull the new one in it's place.

When you get to end of new chain detach old chain from the other end of new chain. Hook ends of new chain together. You are done.

 

Those I know who have done this have removed the camshafts so that no bent valve issues arise. There is a master link on the camchain so use a chain breaker on it and attach the new chain to the old one. Use some wire to tie then together (since you can't use the master link yet) just to make sure you don't lose them down the camchain tunnel. Keep them tight and let the crank gear pull them through.

 

20,000 miles and you think you need a Cam Chain??? No way! Not yet!

It ain't the chain!

Pull the tensioner. Field strip and clean it so nice a Marine Corp Drill Instructor would use yours as "Good example."

Put it together and "Field Test it" in the palms of your hands. If it's binding;
"Shine-up" the sides of the tension plunger shaft with 800.

Clean it; again. Palm test it a few times to make sure it will "Pop-a-notch" when the Cam Chain needs to have some slack taken-up.

You got close to 30,000 miles to go before you need a Cam Chain.

 

I've been through Marine Corps boot camp. I don't think such a thing is possible. 8)

 

Kewl.

I thought the cam chains held up longer than 20,000 judging from everyone elses comments, but I didn't know the automatic tensioner was a "wear" item. This would definately explain the "slack" I have then. This sounds like a much easier (cheaper) fix at the very least.

Now I gotta find in my Haynes how to get that out. haha

Thanks for the info guys.

 

Once you remove the tensioner, examine the cam chain, specifically by trying to twist it sideways.. you should not be able to, at all. .. it must pass this test regardless of mileage...note that a new OEM chain is like $30, a savings I wouldn't take.

 

Tensioner is easy, easier still with the carbs out. Two bolts and it's yours.

 

YOUR BIKE ... that '82 Model ... Just ~> might <~ NOT have an Auto-tensioner.

The run of production for '82 Bikes was dominated by bikes meant for Canada and Great Britain. The "Brit-bikes" (particularly 650's) didn't get Automatic Cam Chain tensioners.

Maybe your's isn't Auto.
Checkin'-it-out is free!

(If you mess-up the gasket pulling the tensioner ... make-up a new one and seal it GOOD! Hot-oil Niagra Falls is held-back by that gasket. Seal it up tight!)

And another note:

If push comes to shove on this job and it is determined that you are going to need to install a New Cam Chain ... I want you to have a DETAILED set off instructions before you lay a wench on the engine.

The simplified instructions appearing earlier in this thread are incomplete and need to be more specific with regard to technical issues and safety precautions to be observed while performing the installation of a new Cam Chain.

When a Factory Workshop Manual devotes several pages of instructions, illustrations and cautions to be observed doing a new Cam Chain install ...
all that information needs to be conveyed to anyone about to do the job for the first time.

If we tell somebody, "It's a piece-'o-cake."

Let's also make sure that they know that it ain't a Betty Crocker Cake Mix.
It's a Cake you have to make ... from scratch.
There's a long recipe. Follow it and get a great desert!
Leave-out an ingredient and you're cookin'-up a disaster!

 

I have been searching for some detailed instructions should the chain need replacing and the closest I can get is off the xs11.com website.

http://www.xs11.com/tips/maintenance/maint10.shtml

This being some other info other than what my Haynes manual gives in paragraph 7. Not sure exactly how different the two heads/blocks are internally, but by reading the instructions and looking at the pics in my Haynes manual I see what they are talking about on the xs11 website. Really, I think I understand the process other than how to do it without removing your cams... I don't understand how you are to get all three sprockets to turn at the same time with twice the chain length and not be worried about messing up the cam timing. If this is done or you jump a tooth on one of the sprockets, I would have to pull the cams then to retime them anyways, right? Pulling the cams certainly seems more logical before feeding the chain through, but that would be "another" first time attempt for me also. But yes, this is the worst case scenario.

My Haynes manual says that an '82 750 J should have an automatic chain tensioner. How will I know when I remove the two bolts holding the tensioner in place. Mine has two allen bolts attaching it to the block, with what looks like a bolt coming from protrusion in the middle. It looks to be an auto from my best deduction. I guess I am hoping to just clean and manually adjust the tensioner using the 2 turns counter-clockwise and one abrupt clockwise turn to get her back to being quiet and vibration free.

Don't worry though, you guys will be the first to be called upon if I get into trouble or if I even get nervous about getting in trouble..

 

This is a good point Rick! The manual tensioner is easy to set. Take off the left point cover, the one with the "YICS" on it and rotate the crankshaft with a 19mm wrench counterlockwise until the pointer aligns with the "C" mark. Then loosen the cam tensioner ower jam nut first followed by the main bolt. Listen for a click. If you hear one then the tensioner was not producing enough tension before and now should be. Tighten the bolt then jam nut and crank to listen for camchain noise. Hopefully you will hear camchain quiet!

 

Let's be very happy to find a Automatic Tensioner and hope that some "sittin'-around-awhile" issue can be cleaned-up and your bike back put back in the starting line-up.

It's nice to find simple fixes and avoid doing unnecessary projects.

I looked at the XS-11 Link. The process has similarities. Start at TDC and get the cams off the valve train so you can turn the crank without the pistons crashing into open valves.

 

This won't work for an auto tensioner. IF you loosen the two allen bolts that hold an auto tensioner in then you have to remove it completely! I would loosen the bolt sticking out in the center by a quarter turn since it is hard to loosen once the tensioner is out and then remove the tensioner.
With the auto tensioner out remove the center bolt which is spring loaded. Actually two springs, one inside the other. Clean it well. Before installing the plunger MUST be pushed all the way back in. There is a little ratchet mechanism that holds the plunger out and keeps it from being pushed back so that tension is always constant. Push it with one finger and then push the plunger all the way back in. Then with the timing pointer pointing to the "C" mark, install the tensioner body and torque the allen bolts to 7.2 ftlbs. Next install the two springs followed by the center bolt. As you screw the bolt in you willl hear the plunger click as it takes up the slack. Once in torque the center bolt to 11 ftlbs.
The difference between an auto and manual tensioner is easy to see. The auto is like you described. Two allen bolts on either side holding it to the block with "one" center bolt. The manual has two allen bolts either side, and a long center protusion of the tensioner body. Perpendicular to that is the retaining bolt with a jam nut.