Timing way off, points cam is out of position

diMarzzio

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Hi everyone,

I'm "new" here, but I've been reading this forum for almost 3 years, after I got my bike.

I have an XS1 motor. Yesterday, I changed the advance assembly plate because the 2 stoppers (the arms that limit the weights' movement) were cracking and I was afraid that they would come off. After that, I continued with inspecting the cam chain tensioner, they were a bit loose. But before I adjusted it, I took off the tensioner to see if it had the ring washer/dampener or not, because I read that washer can help eliminate clicking sound from the top end.

The tensioner was the Type A obviously, and turned out it didn't have any washer in it, just the rod, spring, and adjuster bolt. Before I did the adjustment, I pushed the tensioner rod with my finger to the inside, trying to see/feel how it worked. I pushed it in several times, and I got some "clicks". Well it didn't really make a clicking sound, but I don't know how to describe it well because I'm not native English speaker. It just felt like the rod was sliding from a lower position to an upper position. Because I didn't have a copper washer available to be installed as dampener, I decide to put it back in and adjusted it according to the guide, allowing 1 or 2 mm movement.

After that, I tried to turn the engine on to confirm if the adjustment was correct, but the starter was kicking back. I figured I needed to adjust the points. Before I did the adjustment, I took off the points assembly and clean it with carb cleaner and contact cleaner because it was dirty. I put it back on and set the gaps. And then, when I did the static adjustment, the timing was way too advance and adjustment of the points couldn't compensate it. That's were I noticed that the points cam was out of position. I read that when the rotor is at TDC mark, the pin on the cam should be on top or bottom position. Mine was past the top or bottom position when rotor at TDC. I attached the picture of the pin position, from the governor side, when rotor is at TDC mark.

What did I do wrong? Did I jumped few teeth when I was poking my can chain tensioner with finger? How do I fix this?

Thanks everyone, sorry if I wrote it too long.
 

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First, welcome to the forum!
It certainly looks like you jumped a tooth at the crank. That looks about 20° too advance... which would be one tooth at the crank.
Maybe try repeating what you did with the tensioner and rotating the crank forward at the same time? Try to get it (the crank gear) to jump back one tooth. Not sure if that would work, but short of tearing the engine down it's all I can think to do.
 
I would as a first step take out a spark plug and turn the engine to TDC top dead center
A small wooden stick in the spark plug hole or better.
And then look at the alternator markings so they are in sync.
The reason being that in a rewound rotor the markings can be off.
Then when that is OK inspect the cam Position. Whit the pistons and marking on the rotor still at the right place
Se where we are at.
These same positions can be a help if you try to get it back without taking the motor apart.
 
Hi Jim, thanks. After reading your advice, I went on and tried that. Basically I removed the tensioner bolt, and pushed the rod in with my finger to apply pressure and feel what might happen. I rotate the crank slowly, until a point where (I think) the piston went down and I felt fast movement of the chain (the rod got a sudden big push). After that I rotated the crank again slowly for a short moment before it got stuck, I couldn't rotate it further. I was thinking for a while, then I rotated the crank back a little and there was a clanking sound and I was able to rotate the crank again. The cam has changed position, I think it moved further (?) Please see the image below at TDC.

Thank Jan. I had the left plug removed so I could see the piston. I guess the piston and the alternator marking are in sync. But tomorrow I'll try your wooden stick method to confirm if the marking is still correct.
 

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Yep, if you're at TDC... you jumped another tooth or two. At this point you have nothing to lose, maybe remove the tensioner completely and see if you can get the chain to jump back the 2 teeth. Or maybe keep going in that direction.... back around to where it's supposed to be.
 
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My :twocents:
If you are going to try and jump teeth to get it back in time you probably should loosen the valves up as far as they will go.
If the chain has stretched that much I would seriously consider replacing it.
 
The thing I'm worried about with turning the engine and trying to get the cam chain to jump is interference between valves and pistons. Perhaps the easiest way to avoid valves hitting pistons would be to remove the adjuster bolts from all four rocker arms. Once the cam chain is back in the correct position, the engine can be set to TDC and the adjusters refitted - probably be able to fit two at that moment, the turn the engine 360° and fit the others.

Edit - crossed in the post with GLJ who has the same concern.
 
My :twocents:
If you are going to try and jump teeth to get it back in time you probably should loosen the valves up as far as they will go.
If the chain has stretched that much I would seriously consider replacing it.
The thing I'm worried about with turning the engine and trying to get the cam chain to jump is interference between valves and pistons. Perhaps the easiest way to avoid valves hitting pistons would be to remove the adjuster bolts from all four rocker arms. Once the cam chain is back in the correct position, the engine can be set to TDC and the adjusters refitted - probably be able to fit two at that moment, the turn the engine 360° and fit the others.

Edit - crossed in the post with GLJ who has the same concern.
Oooh.... good point guys. I'd definitely back off or remove the adjusters.
 
Thanks Jim, GLJ, Raymond, and toglhot.

I finally managed to fix the problem. What I did was:
1. Removed the cam chain tensioner completely.
2. Removed all spark plugs.
3. Rotated the crank with ring spanner, while also holding the points cam bolt with another ring spanner to keep the tension.

I rotated the crank slowly, while giving small pressure to the points cam. After so many turns, I finally managed to jump the teeth back. I did it slowly and gently so that I didn't ruin anything.

Toglhot's tips are probably better, but I didn't know how to remove the cam bearing or the sump filter plate. I was just afraid of making more mess. But it's great for future reference if someone came upon the same problem.

Thanks everyone.
 
Good, I take it the cam position is sorted now?

On removing the sump filter plate, it's really not difficult and it's a maintenance task. Best to drain the oil first unless you like making a mess. Then six small bolts, 10 mm heads. You might find a 3/8 or 1/4 drive socket best to get at the ones near the frame tubes. The oil filter comes out with the sump plate and needs checking - they can split.
 
Thanks Jim, GLJ, Raymond, and toglhot.

I finally managed to fix the problem. What I did was:
1. Removed the cam chain tensioner completely.
2. Removed all spark plugs.
3. Rotated the crank with ring spanner, while also holding the points cam bolt with another ring spanner to keep the tension.

I rotated the crank slowly, while giving small pressure to the points cam. After so many turns, I finally managed to jump the teeth back. I did it slowly and gently so that I didn't ruin anything.

Toglhot's tips are probably better, but I didn't know how to remove the cam bearing or the sump filter plate. I was just afraid of making more mess. But it's great for future reference if someone came upon the same problem.

Thanks everyone.
Thanks Jim, GLJ, Raymond, and toglhot.

I finally managed to fix the problem. What I did was:
1. Removed the cam chain tensioner completely.
2. Removed all spark plugs.
3. Rotated the crank with ring spanner, while also holding the points cam bolt with another ring spanner to keep the tension.

I rotated the crank slowly, while giving small pressure to the points cam. After so many turns, I finally managed to jump the teeth back. I did it slowly and gently so that I didn't ruin anything.

Toglhot's tips are probably better, but I didn't know how to remove the cam bearing or the sump filter plate. I was just afraid of making more mess. But it's great for future reference if someone came upon the same problem.

Thanks everyone.
Amazing...you removed the entire tensioner and rotated the engine and it didn't slip more? You were able to control the amount of teeth the chain stopped on? Those valve springs are pretty strong and that little 6!m bolt in the end of that aluminum rod on the points doesn't take alot to strip.,I'd be afraid to try.
 
Thanks Jim, GLJ, Raymond, and toglhot.

I finally managed to fix the problem. What I did was:
1. Removed the cam chain tensioner completely.
2. Removed all spark plugs.
3. Rotated the crank with ring spanner, while also holding the points cam bolt with another ring spanner to keep the tension.

I rotated the crank slowly, while giving small pressure to the points cam. After so many turns, I finally managed to jump the teeth back. I did it slowly and gently so that I didn't ruin anything.

Toglhot's tips are probably better, but I didn't know how to remove the cam bearing or the sump filter plate. I was just afraid of making more mess. But it's great for future reference if someone came upon the same problem.

Thanks everyone.
DiMarzio what happened to you and your engine is exactly what happened to me and mine. I was changing a tensioner gasket and got to "fingering" around with the tensioner just like you. I have the same engine as you. I guess we are alot alike.lol
I have been scratching my head in an attempt to figure out away to avoid having to remove the engine to repair it...like you. I swear just today I thought to myself if there was away I could hold onto the camshaft while turning the engine over by hand I could possibly control the amount of teeth it slips and prevent the cam from advancing when it does slip because that's what it does. Do you know how you couldn't get the points to set right and that's t'sat drew your attention to the cam position? Same here but I took a file and cut away at the points plate until i could retard the timing enough to catch back up with it. LoL I've got a points plate now that has almost 180 degrees of adjustable movement. Man I'm glad I read your post even if I don't follow your steps I at least know I'm not the only one out there who likes to stick his fingers in things he shouldn't....
 
Good, I take it the cam position is sorted now?

On removing the sump filter plate, it's really not difficult and it's a maintenance task. Best to drain the oil first unless you like making a mess. Then six small bolts, 10 mm heads. You might find a 3/8 or 1/4 drive socket best to get at the ones near the frame tubes. The oil filter comes out with the sump plate and needs checking - they can split.

Yes, the cam position is sorted now. On the sump filter thing, I'll do it next time I change the oil. I've never changed the oil by myself, but it's actually on top of my to-do list. I'll read more about that. Thanks.

Amazing...you removed the entire tensioner and rotated the engine and it didn't slip more? You were able to control the amount of teeth the chain stopped on? Those valve springs are pretty strong and that little 6!m bolt in the end of that aluminum rod on the points doesn't take alot to strip.,I'd be afraid to try.

DiMarzio what happened to you and your engine is exactly what happened to me and mine. I was changing a tensioner gasket and got to "fingering" around with the tensioner just like you. I have the same engine as you. I guess we are alot alike.lol
I have been scratching my head in an attempt to figure out away to avoid having to remove the engine to repair it...like you. I swear just today I thought to myself if there was away I could hold onto the camshaft while turning the engine over by hand I could possibly control the amount of teeth it slips and prevent the cam from advancing when it does slip because that's what it does. Do you know how you couldn't get the points to set right and that's t'sat drew your attention to the cam position? Same here but I took a file and cut away at the points plate until i could retard the timing enough to catch back up with it. LoL I've got a points plate now that has almost 180 degrees of adjustable movement. Man I'm glad I read your post even if I don't follow your steps I at least know I'm not the only one out there who likes to stick his fingers in things he shouldn't....

LOL, I guess it was curiosity that got us into trouble, but made us learn.

I think it slipped in the first place because I used a ratchet to rotate the 17mm crank bolt. With the plugs removed, when the pistons passed the TDC they just fell down fast because the ratchet wouldn't hold the spinning bolt. When I used a spanner to rotate the crank, and another spanner to hold the cam, I have full control over the rotation. And that way I could feel the tension of the chain. At some point the chain got tensed, that was when the chain in a position to possibly jump a tooth. It took me many rotations though.

I'm actually amazed at your solution :D But if I understand it correctly, then your cam is still off now, isn't it? If yes, then your valves are also off? How's your engine run?
 
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