Cam bearing replacing

It would be interesting to hear the details of what they did.
I've been trying to figure out how to press the gear back on and have the marks lined up, exactly. Here again, without a key it won't be the easiest thing to do on the first try.
Your luck has been good so far...

I'll try to get some pics when I go back there later today ...

No, all bikes are not made like this.

In fact if I remember correctly, the X-light has plain bearings on both ends of the cams. There is only one bearing in the cam drive and it is behind the gear that carries the cam chain.....that gear is not the best either but it is easier to change.

I'd look for an old cam on ebay to practice on before I did the real thing!

I bought a burned up head for an x-light just to practice heli-coiling a stripped head bolt on the real thing.

These guys just busted the old bearing off the shaft and placed a jig under the gear and pressed it off ..

Next, they just eye-balled the marks on the gear and cam to replace the gear ... probably heated the gear and pressed it back on ...

Next, was cranking time ....

The engine started but would not REV up any RPMs... Just sort of had a muffled sound and cut out badly when I twisted the throttle .... I'm back to checking all the timing marks ....

Did the scratch marks look lined up on the re-press job?

I found that my timing marks on the cam gears had to be lined up a very specific way to be correct.

Line up your TDC mark and then take a pic of the slope of the lobes and post it here. That's how I decided my marks were weird, one lobe was slanted a different slope than the other lobe.

Yes the scratch marks looked good ... I'll take a pic of the cam lobes at TDC later ... I gotta go do something currently ...

I was thinking the same thing with the lobes ... I'll post a picture in a little bit ...

Here are the lobes setting at TDC ...I got several pics of the cams but nothing I can use to confirm where they were setting exactly when
at in TDC ...

Edit: I did find some pics to compare the lobe position to when the engine is at TDC ...

Your intake cam looks way low, and your exhaust may be a little high. A pic from the other side would be good. Dfeckel did the post about perfect cam timing, here's one of his pics:

I was reading his write up on the timing as I was fumbling my way through the process .. forgot he had a pic there for comparing where the lobes are at sitting at TDC ....

Yep on the intake side lobes ... I went ahead and rotated the intake cam up a few teeth and the bike stated and ran pretty good but still had a slight bog when REVing ... I'll move the cam another tooth or two tomorrow and see if that helps more .... I can't see anything to cause the timing to be off other than the gear was not put on the shaft in the correct location ...

Just put a degree wheel on it and check the lobe center of both cams. Cam timing is super important to engine performance and if not correct will turn an engine into a gutless pig.

Ok but what do I check them against? Or what am I looking for with the degrees?

Your exhaust looks OK from this angle, Dan and I both know that your exhaust cam can be off one tooth and the bike will run great, the e-start wont work tho.

Bad news ... The gear is slipping on the shaft ... That is why the machine was timed correctly at first but after trying to run the engine, the timing was off ...

I removed the valve cover today expecting to find the intake lobes pointing upward at TDC, again they were pointing downwards ... I then used a couple tools to move the gear on the shaft ...

Back to the drawing board ... Has anyone ever successfully fixed such an issue as a pressed on gear slipping on its shaft?

UPDATE: The fix (tig welded using a stainless steel rod) is in the pic ... Uncharted waters here and I'm hoping for the best ...


Any future removals of that gear? Unknown .....

I like your style!
I think I would have been tempted to skip weld it though.

This cam event really caught me off-guard .... I have not rode any this week or much last week... So I've gotta have a fix now and get on with it to test all the fixes before I loose more riding time .... I'll worry about the next bearing change after I have ridden it a few days ...

I did tell them at first to just weld 1/4 length bead on each side .... But changed my mine and after the cam had cooled a little, so he closed up the remainder of the circle ... I'm told this will work well as a fix. The EX cam has me we a little spooked ... I hope it holds and I'll be sure to be on the lookout for low power as a sign it has gone belly-up ....

I have heard of them welded before. That's why most change the cam.

You're super lucky it didn't bend valves. IMO this set up should have a keyway and a bolt holding the gear on from the factory.

I guess its lucky, I feel lucky enough so far ....

The cam will not open the valves on first rotation due to the slippage ... Might be OK here but on the second attempt to open the valves, the lobes are in the wrong place to start the opening process ... Not sure what happens here but maybe the cam gear just slips again and no valves are opened ...

Yep seems like anything would be better than this design ...ESP with just expensive parts being what the real fix is all about ....

I'll just wait and see what the next bearing change will be ... I hope I can get close to the same number of hrs on them (or more) before they get loose again ....

I would have been more inclined to drill and tap a small (~3-4mm) hole for a cup end set-screw with the centre of the hole located at the point the cam gear and shaft intersect before I pressed them apart initially. This would ensure that the camshaft/gear is assembled back together in the correct orientation and prevent slippage on the shaft after re-assembly as well as making a possible next bearing change comparatively simple and easy. Some Loctite 2620 or similar applied to a solvent cleaned surface would ensure that the set-screw is not going anywhere as well.