Camchain Tensioner Might be Shot... [Maxim 550]

Hey All!

I bought my bike at the end of the riding season last year. It was running, then got tipped and stopped but a quick visit to the Church of Clean brought the bike back to life. It then spent the winter in storage, and now that I'm riding it, I've noticed a rattling when the engine isn't under load (not accelerating or intermittently at idle)

Looking through the threads here, it seemed most likely that the camchain tensioner needed adjusting, but those same threads showed examples of the automatic tensioners that seemed to match the one on my bike. I have a Clymer maintenance manual that details how to adjust the automatic tensioner, but when tightening down the adjuster bolt I was not able to get it to the recommended tightness - the bolt just keeps spinning. The threads are still good, I checked that they weren't stripped or crossthreaded. Not quite sure what going on with the tensioner, but I was hoping someone on here might be able to tell whats going on, and what I might be able to do to fix it beyond simply replacing it. On replacing it, I was not able to see a compatible autotensioner in the XJ4Ever catalogue, could that be a possible cause for the issue?

I did confirm that the rattle is the camchain, the valve cover has twin wear tracks where the chain plates have been hitting...

 

The 550 rattles at idle due to the primary chain tensioner. The rattle disappears when the oil pressure operates the tensioner. Can you pull the cam chain away from the sprockets, is there a lot of slack in it. What mileage has the bike done?

 

The two mounting bolts should be snugged to about 8.7 ft-lbs and the adjuster to 6.5 ft-lb. If the adjuster just spins there is definitely an issue with the threads. If it is screwed all the way in you should have correct chain tension anyway.

 

It can't be lifted from the gears, but it can be lifted between them. The bike has 42546 km on the odometer. That sounds quite similar to what I'm seeing, but I haven't been out on the road with it since I noticed the rattle. I'll have to check if it actually requires load or if it just needs to be above idle...would increasing the idle speed get rid of the rattle in that case?

The two mounting bolts are snugged to spec. The adjuster is the odd part. I checked the adjuster bolt threads and they're fine. When the bolt is threaded it rotates smoothly until a certain point when it starts spinning when I try to tighten it. If I try to loosen the bolt, it starts backing out without any issue.

 

The adjuster should never spin, it has a torque spec which could not be tightened to if it spins. The threads might be there but so worn that they allow spinning. Either the bolt is trash or the housing is.

 

Try increasing the idle speed. If it's the primary chain tensioner the rattle should stop as the tensioner is operated with oil pressure. If you have the cam chain tensioner removed extend it fully and push it back into position on the engine. If it is meeting the block with the tensioner fully extended the cam chain is worn. Are the scratches on the inside of the cam cover directly above the area between the cams where you can lift the chain?

 

Would that require replacement of the whole tensioner or is the housing a replaceable part?

The idle speed is currently about 2,000 rpm, what would be a good benchmark to adjust it to? Where might I find documentation on the proper process for removing and replacing the tensioner? I haven't removed it from the engine yet, I was concerned about damaging something by removing or replacing it incorrectly. The scratches are indeed directly underneath where the chain can be lifted, right above the cam chain guide.

 

The primary chain tensioner should be pressurised at 2000rpm l think. You need to set the engine to top dead centre on cylinder 1 before you remove the tensioner. Is there anything about the process in your Clymer manual. It should be in the Haynes manual for your bike. I will look and see if there is a how to article regarding the tensioner.

 

Does your adjuster look like this from a 650?

https://xjbikes.com/forums/threads/camchain-tensioner.119087/

@Huntchuks will know if it's the same.

 

OK, so I am officially out of this conversation. I didn't see that the question was about a 550 and that the tensioner is the manual type.

 

Thank you very much for your help!