Motor spun fine on bench, now in frame won't kick

[Jake Violando]

I have a 1980 xs650 that I put a new timing chain guide in. The motor spun fine on the bench. Now that it's all hooked back up to my bike, I kicked it over twice, then when I went to get the hard kick to start it, it locked. I can't spin the rotor because the nut spins loose from the tension. Ugh I really don't want to have to pull the motor and wait for buddies to show up. Ideas?

 

[TwoManyXS1Bs]

Put it in 5th or 4th gear and nudge it backwards.

If it remains locked, or frees up, either way is significant in diagnosing...

 

[Jake Violando]

Nothing happened. I just pulled the motor, removed the top cover, and magically it spun freely about two full revolutions. Now stuck again. Wtf! This timing chain guide has been the biggest Pain.

 

[nj1639]

Check the timing.

 

[Jake Violando]

I can't spin the rotor the correct way, theirs that "locked" tension and so much it actually loosened my rotor nut

 

[gggGary]

Like said check the cam is timed to the crankshaft pretty hard to push the valves through the pistons. One gotcha is a stator not indexed to the alignment pin on the crankcase will jam against the rotor hard enough to keep it from spinning. Don't ask why I know this.

 

[retiredgentleman]

When you installed the new camchain guide, did you use new nuts from Mikesxs?
If you did, maybe this thread will be of interest:
http://www.xs650.com/threads/new-engine-too-tight.47773/

This may not apply to you if you used the stock nuts to mount the new guide.

 

[Jake Violando]

I did use stock bolts for the guide. Well I took off the top cover, and removed one side cam bearings. Motor turns with kicker smooth as can be. Put the bearings back on, top back on, and locked! I'm about to take it to a shop...

 

[TwoManyXS1Bs]

How 'bout posting some pics.
Top of head, camcover removed, exposed cam.
Inside of camcover.
Rotor, with timing mark, at that 'frozen' position...

 

[littlebill31]

Did you try loosening the tappets all the way, then trying it?

 

[kshansen]

Trouble shooting from a distance is not easy under the best of cases but it does sound like the cam timing is off.

I've only done one of these XS650 engines an it has been a couple months since I installed the cam so I won't try to explain the timing procedure off the top of my head. Could you be using the wrong marks on the cam gear or even have cam in swapped end for end?

As gggGary says if for some reason the alternator rotor is not positioned correctly on the crankshaft you may think you had it at top center but it was actually off from where it should be.

Exhaust valves stay open while piston is coming up on the exhaust stroke so if the cam is retarded even a tooth or two on the gear it may be causing this problem. Just for kicks I'd try backing way off the valves on both exhausts and see if that does not change things.

 

[TwoManyXS1Bs]

... it spun freely about two full revolutions. Now stuck again...

The primary drive reduction is about 2.7:1. A piece of metal, or broken tooth on clutch basket, could jam in there.

That's enuff turns to get a full revolution of the camshaft.

That's also enuff turns to move the camchain's master link from one end to another. Mangled link?

*Where* it sticks is important. Near TDC, near BDC, somewhere in between, always the same place?

 

[gggGary]

Stops when valves are operating OP has avoided any answer about did he time the cam correctly.
Draw your own conclusions.

 

[TwoManyXS1Bs]

Yeah, dunno, confused here...

 

[B Burdine97]

Well in his defense boys he said he has the same issue when he had the top cover off so we know that it's not the valves hitting the pistons and not allowing it to reach TDC. Also he said he's gonna take it to a shop so there's no use in helping the guy if he won't listen to any of us so let him waste his own money then.
Good luck Jake.

 

[Jake Violando]

The tappets are all loose. It spins free as can be with the crank bearings off on one side. When it locks its before TDC on rotor. I'll get pics momentarily

 

[Jake Violando]

Here is her currently

 

[nj1639]

Looks like your cam position is off, maybe a couple of teeth.
Do you have a manual?

Pic 2 looks off one, maybe two teeth, pic four looks off four, maybe five!

Look at the cam index marks......if the engine is at TDC then the index mark is off. That notch should be dead center to the top - with a dot off to the side, horizontal to the top of the engine.

 

[gggGary]

Watch this video, ignore the babble about the masterlink which makes NO difference. He shows you the cam marks and and the crank at TDC, is that how yours looks?

 

[xjwmx]

In your very first picture...I've never seen a rotor like that but the timing mark on the stator is lined up with a part number on the rotor, not the rotors timing mark. So -- line up TDC mark on rotor with TDC mark on stator. Then without letting the rotor turn, make the cam sprocket so the mark is as straight up as can be. Then you should be good..