Rattle...

[claybear]

Quick question, I built my chopper over the winter and just got around to getting it out and about, (had a lot of minor bugs, and the weather sucks in MN), I'm getting what sounds to be a rattle of sorts, and kind of a little heavier vibration right around the 55mph mark.. You guys think it's something serious, or is it pretty normal for one of these engines in a rigid frame? I just want opinions so I know if I should be worrying about it or not.. Thank you guys.

 

[claybear]

Should add, can't really tell where the rattle is coming from since it's only at certain speeds, it does seem like it's around the engine though.. Maybe I need a top motor mount?

 

[Classic]

When is the last time you set your cam chain tension and what are your valve clearances set to?

 

[Dusty]

I had the same problem on my last 2 builds. It turned out to be the drive chain slapping the bottom of my fake oil bag on the first build. The second was the chain hitting the under side of the chain guard. It only did it sometimes. I swore I had valve trouble, because it sounded like it was coming from the engine. I swapped engines in both bike, and it still did it. Boy was my face red when I found out where it was coming from.
Check and see what your chain could be slapping against.

 

[sreimer]

And yes vibration is normal. Regearing does help if you haven't done that already.

 

[claybear]

When is the last time you set your cam chain tension and what are your valve clearances set to?

I just did the cam chain tension yesterday, the valves are set to spec, I put in a top mount today and it seemed to help some, but I'm thinking it's just more of a vibration thing.. Crap keeps shaking right off..

 

[Classic]

A good carb synchronization and exact ignition timing will get rid of a lot of vibes.

 

[claybear]

A good carb synchronization and exact ignition timing will get rid of a lot of vibes.

I do have to sync the carbs yet, I had them out yesterday to do the jets and noticed some pin holes in the diaphrams, but looked online to see if there was a way to fix that and used some plasticoat to seal up the holes...But yeah, I'll have to try to sync them if I can. As far as the ignition goes, I don't think it's really adjustable on there is it? It has the electronic ignition.

 

[claybear]

And also, I added a top motormount, (a peice I forgot to make at the time) and that seemed to help some. She still vibrates more than a pornstar, but it's better now..

 

[Classic]

Your TCI isn't really adjustable iirc. I would suggest the diaphragms from JBM Industries. They are very high quality.

Hey we should meet up some time. You've got one of the coolest XS's I've ever seen.