Stuck Cam Chain Adjuster

Hope this hasn't been asked before, but I did a search and didn't find and answer to this. I can't seem to get my cam chain to adjust using the procedure defined in my Clymer manual. It's the same procedure I've seen documented here. I turned the engine to the "T" mark just past the 2-3 mark, then loosened the bolt on the adjuster. I expected to hear a "click" or something, but I didn't hear anything, and the valvetrain noise didn't change. I also tried getting the engine hot first. That didn't help. I also tried tapping on the adjuster with a socket & extention, hoping to knock it loose. That didn't work either. I guess it's possible that it worked, but I expected the engine to get quieter. Is there a way I verify whether the adjustment worked? If not, what are my options now? I assume I'll need to remove the adjuster, "Reset" it, and re-install it.

Not being a bona-fide expert in things 650, I hesitate to attempt "authoritative" advice, but the symptoms sound common enough...

Spring-loaded "automatic" adjusters have a limited amount of travel set by a notch at the end of the spring shaft - a look at the parts drawing shold confirm that. It's possible - even likely - that the cam chain has stretched beyond the range of the shaft to take up the slack.

The other possibility is that the spring has weakened a bit, not providing enough *sproing* to the spring, as it were.

Either would explain the lack of that satisfying "click" you're seeking.

Looks like you're due for a little "adjuster surgery". Look over the parts diagram to get familiar with the exact setup - the adjuster-end hardware changed somewhat in the 77-78 time frame on the 1000 motors - and have at. Lube the bejesus out of the shaft, stretch the spring a bit, and give 'er a try...

There is a flat area on the side of the rod. At then end and towards the rear, the flat spot becomes round and this area forms sort of a "tooth". This "tooth" can dig into the soft aluminum body of the adjuster and cause it to hang. Get a new gasket and then remove the old adjuster. Pull out the rod and spring and clean the innards and then lube the innards with grease. Put the rod in and loosen the bolt that holds the rod a couple times to make sure it pops out. I personally think it is silly to pick a point on the mechanical advance to let the rod out... what difference can it make? To my mind, it is more effective to let the rod out and turn the engine over at least once (one rotation) so that the rod can "FIND" the slackest spot and take up maximum tension.

If you don't hear the snick when you loose the holding bolt, you are right to assume it isn't popping out. The other alternative is that it IS popping out as far as it can and your chain is stretched and needs replaced. If this is the case, get a chain w/master link from www.z1enterprises.com . Join the new chain to the old and pull it through and properly peen the ends of the master link. They can sell you a tool to do this as well as break the old chain if you aren't comfortable with doing it with other hand tools. The chain tool costs more than the chain...

Thanks, everyone for the replies. I wouldn't think that my chain would be stretched beyond adjustment range, as the bike only has 17000 mi on it. I would think that the chain would be good for much more than that. Sounds like it's time for some exploratory surgery.

Before doing "surgery" as you put it, I suggest you remove your valve cover. Also remove your spark plugs and the points cover. Get a socket wrench and 17mm socket and turn the inner nut on your mechanical timing advance end to turn the engine over. OBSERVE the cam chain as it passes the idler assembly... move the chain back and forth... if it bunches some, it has slack in it. If the adjuster is extended out fully and it still has slack, the chain needs to be replaced.

You can replace the chain AT THIS POINT if you have a chain with a master link. Break the old chain (don't lose the ends down into the engine cases). Fasten the new chain to the old and pull it around your crank by turning that 17mm nut. Once both ends of the new chain are looped around the crank, toss the old chain and put the plate on the master link and peen the ends with a cam chain tool made for this purpose. It is easier to use this tool when the top end is on the bike than trying to figure out a way to brace the back of the chain and peen it with a punch.

Z1Enterprises.com can probably help with the new chain, master link and tool, if it is needed.

Well, I think I fixed it. Without taking anything apart. It appears that I was not aware of the locknut on the bolt, and the bolt didn't seem to be screwed in far enough. When I loosened the bolt, the socket just slipped over the locknut also, and I loosened and tightened them together. So the adjuster was free to float. This would explain why I never heard the "click" after loosening the bolt. I tightened it all down and it's a bit quieter now. Not a lot, but it is noticible.

Of course, this raises another question. Since it has probably been this way for several thousand miles, is it likely that there is any damage? If so, what would be damaged?

Wiredgeorge, would you really want the adjuster adjusted to the loosest position on the chain? I would think that if you did this, you would have the chain under too much tension everywhere else. The chain might survive fine, but I would think that the adjuster wouldn't last too long.

Thanks, everyone for the help.

Post edited by: bemoore, at: 2006/06/09 09:50

The adjuster's spring isn't all that beefy. Don't worry about too much tension... there isn't a great deal of difference at any one spot. I stand by my suggestion to turn the engine over by hand to find the most slack, then tighten the locknut.