Weird noise on Model D

[Brater]

Hi,

after a half year of a break my model D makes a rattling/snoring noise. I tried to make a short video of it:
https://drive.google.com/file/d/1t1jMmR ... sp=sharing
(the sound is a little bit quiet)
It sounds like as if the chain would rub somewhere but I did not find anything.
The chain is oiled, the chain joints are flexible. I tried to found the source of the noise - could be the sprocket?

Do you have any idea, how to get rid of this noise?

Thank you in advance.

[jackarabit]

Could be the plexi splash shield/noise baffle which should seat on the flanges of the u-channel housing the chain and chain return mech is riding on one or more rivnuts which receive the machine screws that secure the rear strut of the front leg and contacting the chain links.

Get underneath, inspect, and correct position of shield (bang it about or humor it til it seats between the rivnuts) or break the rower sections, pull the shield completely out, recouple the rower sections.

Row a few strokes. No noise? Got your culprit.

[Brater]

Thank you for the advice, jackarabbit.
I removed the shield (based on https://www.concept2.de/files/pdf/us/in ... cParts.pdf it should be PN 1526).
The noise was still there.
After this I removed the flywheel (to look, if there is dust or anything in it). The noise gets even more obvious. I also uploaded another video https://vimeo.com/666939260. It's much better to hear the noise.
I also removed the end cap (PN 1009), to see if the chain moves somehow strange or rubs against anything. But everything looks fine.

Can anybody help?

(if anybody needs to wait too long for the first video: https://vimeo.com/666938391 )

[Tsnor]

Very that the chain is ON the sprocket. I've seen it come off. When you pull the chain is it spinning the flywheel? If off, the only way I know of to get it back on is to remove the chain from the handle, re-feed it through all the sprockets and then put the handle back on. Trying to force the chain back on the sprocket with the chain in place didn't work for me.

If you removed the plastic shield, and put the rower flywheel assembly upside down, can you then isolate where the noise is coming from ? Maybe something got pulled into the chain mechanism area. If so you need to find it and remove it.

As I read your post you've already eliminated the chance that there is something in the flywheel area. Can't think of much else that could make a noise like chain hitting hard plastic.

[jackarabit]

Get back up in the tunnel and check the entire chain path. Chain can be off the idler pulley and riding the idler shaft OR the idler pulley can wear out and the v-sheave disintegrate and the chain riding on the remains of the pulley.