Cam Chain binding?

[Forden]

I was working on removing shims to get valve clearances in spec when I ran into an issue where the crankshaft wouldn't rotate fully--I'll detail it in smaller bits to make it easier to digest. Also noting that this bike is new to me and hasn't been run yet, though it turned by hand freely and after that with the starter to check compression during my inspection before buying.

-at first I could rotate the crank in both directions, needing to go backwards (counterclockwise) for partial rotations when the shim bucket depressor was installed on exhaust valves. It was normal rotating forward but a little clunky in reverse direction.

-when I returned the next night to finish, I loosened the binding bolt on the chain tensioner, reasoning that maybe it was running rough over it in reverse direction. shortly afterward, the crank would only rotate about 120 degrees, and just stop on either end of that arc. My guess was something on the cam chain gear on the crankshaft was hitting the chain when it engaged. piece of debris, wonky tooth, or the like .

-there were times when turning the crank (only in reverse as I recall) would not turn the cams, as if the gear was slipping the chain altogether. I tried with tensioner in and out, same thing (at first).

-eventually with gentle coaxing and the tensioner out, I got the crank to rotate fully in the forward (clockwise direction). and that's where I am now--I don't want to rotate either direction again until I figure out what's going on.

So:

-I'm steeled to the idea that I may need to remove the top end to get access to the cam chain gear (at least visually), but not sure whether I'll need to split the cases too. It would be nice if no... in any case I'd appreciate any thoughts on anything I might try to diagnose the binding issue before getting started on removing the head. will just removing the top chain guide give me a good look down inside?

-I'm not 100% sure, but the cams look out of phase to me--here is a pic of cam sprockets from the right side with the crank at the TDC mark:
IMG_0007 by Forden Photography, on Flickr

-I read Crazy Steve's cam removal tutorial (https://xs11.club/forum/idle-talk-fo...ment-pictorial) while researching the motion pro valve tool (yes it gave me problems, no I'm not reviving that question). My cams are definitely not lined up at TDC as his were in the picture, and as he is particular about the order of removing the cam sprocket bolts, I would like to know if I can remove them in the order of greatest convenience and also if I am risking anything (like valves hitting pistons) by rotating the crank with my cams positioned as they are.

There's my dilemma, thanks to all in advance for any help or suggestions.

Cheers
Mike

[cajun31]

I was working on removing shims to get valve clearances in spec when I ran into an issue where the crankshaft wouldn't rotate fully--I'll detail it in smaller bits to make it easier to digest. Also noting that this bike is new to me and hasn't been run yet, though it turned by hand freely and after that with the starter to check compression during my inspection before buying.

-at first I could rotate the crank in both directions, needing to go backwards (counterclockwise) for partial rotations when the shim bucket depressor was installed on exhaust valves. It was normal rotating forward but a little clunky in reverse direction.

-when I returned the next night to finish, I loosened the binding bolt on the chain tensioner, reasoning that maybe it was running rough over it in reverse direction. shortly afterward, the crank would only rotate about 120 degrees, and just stop on either end of that arc. My guess was something on the cam chain gear on the crankshaft was hitting the chain when it engaged. piece of debris, wonky tooth, or the like .

-there were times when turning the crank (only in reverse as I recall) would not turn the cams, as if the gear was slipping the chain altogether. I tried with tensioner in and out, same thing (at first).

-eventually with gentle coaxing and the tensioner out, I got the crank to rotate fully in the forward (clockwise direction). and that's where I am now--I don't want to rotate either direction again until I figure out what's going on.

So:

-I'm steeled to the idea that I may need to remove the top end to get access to the cam chain gear (at least visually), but not sure whether I'll need to split the cases too. It would be nice if no... in any case I'd appreciate any thoughts on anything I might try to diagnose the binding issue before getting started on removing the head. will just removing the top chain guide give me a good look down inside?

-I'm not 100% sure, but the cams look out of phase to me--here is a pic of cam sprockets from the right side with the crank at the TDC mark:
IMG_0007 by Forden Photography, on Flickr

-I read Crazy Steve's cam removal tutorial (https://xs11.club/forum/idle-talk-fo...ment-pictorial) while researching the motion pro valve tool (yes it gave me problems, no I'm not reviving that question). My cams are definitely not lined up at TDC as his were in the picture, and as he is particular about the order of removing the cam sprocket bolts, I would like to know if I can remove them in the order of greatest convenience and also if I am risking anything (like valves hitting pistons) by rotating the crank with my cams positioned as they are.

There's my dilemma, thanks to all in advance for any help or suggestions.

Cheers
Mike.

well the bottom line is you should have not have loosened or removed the tensioner. you are probably out of time as the chain has probably slipped a tooth or two. best to proceed with getting the cams out before you bend a valve, if you haven't already. the timing can be re-achieved if all else is well. if it were me and my bike I would go ahead and get the cams out and look at the valves very closely to see if any are bent. if not I would then drain the oil and drop the oil pan. you can get to the bottom of the cam chain and crank from there. if all looks ok then I would acquire a replacement cam chain (might as well replace it) to start with a new one. you state you checked compression so I am assuming it was ok.

[Forden]

Ah. (vicious forehead smack). I thought it would be ok, since I noted in the engine section of manual that there is a point where you rotate the crank after removing the tensioner... live and learn. I suppose if I'm lucky and no valves are bent, having them out will at least provide the opportunity to lap them (and do seals in the process).

I'll have to rotate the crank to get at all four cam sprocket bolts--any cautions before doing that, so I don't make another stupid mistake? reinstall the tensioner, for one?

Thanks.

[cajun31]

Ah. (vicious forehead smack). I thought it would be ok, since I noted in the engine section of manual that there is a point where you rotate the crank after removing the tensioner... live and learn. I suppose if I'm lucky and no valves are bent, having them out will at least provide the opportunity to lap them (and do seals in the process).

I'll have to rotate the crank to get at all four cam sprocket bolts--any cautions before doing that, so I don't make another stupid mistake? reinstall the tensioner, for one?

Thanks.

with the tensioner out you should have a lot of play in the chain. at least enough to be able to mess with the cam sprocket bolts. if not then something else might be going on. and at this point no, do not put the tensioner back in. you will run the risk of bending a valve. worst case scenario if you are going to replace the cam chain as I suggested is to just go ahead and break the chain. just don't allow it to drop in the case. use a couple of coat hanger pieces to hold it up on either side. you can then just remove the cams. use the old chain to thread the new one in. you may not need to remove the head and mess with the valves. how many miles are on the bike?

[bikerphil]

It is possible to rotate the crank with the tensioner out, just make sure you push in thru the hole with your finger or thumb holding the chain guide tight while rotating in the direction of the arrow only.

[cajun31]

It is possible to rotate the crank with the tensioner out, just make sure you push in thru the hole with your finger or thumb holding the chain guide tight while rotating in the direction of the arrow only.

phil, from what he has already done and possibly already being out of time I would advise to not rotate the engine any further.

[Forden]

with the tensioner out you should have a lot of play in the chain. at least enough to be able to mess with the cam sprocket bolts. if not then something else might be going on. and at this point no, do not put the tensioner back in. you will run the risk of bending a valve. worst case scenario if you are going to replace the cam chain as I suggested is to just go ahead and break the chain. just don't allow it to drop in the case. use a couple of coat hanger pieces to hold it up on either side. you can then just remove the cams. use the old chain to thread the new one in. you may not need to remove the head and mess with the valves. how many miles are on the bike?

That makes sense. I'd be pretty surprised if I bent any valves, as I was only turning slowly by hand and never forced it at all. 42K miles on the bike.

[cajun31]

That makes sense. I'd be pretty surprised if I bent any valves, as I was only turning slowly by hand and never forced it at all. 42K miles on the bike.

Honestly, I would just pick up a new cam chain and link and just replace the old chain. The chain is probably ok but you are already there now. Pick up a manual, which can be downloaded, a chain breaker installer tool and an automatic cam chain tensioner from an old VMAX from Ebay and you will be good for many miles.

[Forden]

Thanks for the advice. I've got the manuals (both original and Clymer's), have a chain breaker but have to check the size. I'll check out the vmax tensioners--I'm sure mine is fine but auto adjusting is nice. My GS has one. Any cutoff year for matching from the vmax?
cheers
Mike

[cajun31]

Automatic Cam Chain Tensioners - XS11.club Forums

[Radioguylogs]

Vmax 1985-2007 will work.

[2WheelFun]

Mike, I bought a pair when I did mine. Pm me and I can get it to ya cheap.

[Forden]

Mike, I bought a pair when I did mine. Pm me and I can get it to ya cheap.

PM coming, thanks for the offer! cheers