GypzRogue, a Big Dog and an issue

[GypzRogue]

Hi guys, a friend asked me to look at his 2004 Big Dog for him. It has the S&S Super Sidewinder 107 motor in it, but it has a engine knock. It knocks as each cylinder fires. You can feel it in the seat and the handle bars. The oil pressure seems fine and I killed each cylinder one at a time and the knock still remains. Now I haven't gone any further, which is why I came here instead of chasing my tail. Was wondering if anyone here ran across the same condition. My friend said he had left the bike with a local bike shop to have other minor repairs done to the bike, but after he picked it up he had noticed it had in excess of 125 more miles on it. A little lengthy for a test ride I'd say.
My guess at the top of my head, is that it has scorched pistons. I haven't checked the primary chain tension as of yet, but was just curious if anyone here had ran into the same conditions, before I tear into the motor.

Thanks, Curt

 

[Steve1028]

My first suggestion would be to tell the guy to carry it back to the shop that rode it 125 miles and let them pick up the tab! I had a shop f-up my boat like that one time...they ended up buying it from me!

Oh, and you may want to do an intro before the get here!

 

[barhopper]

I would add no knock gas. What did the shop do to it when it was in there? Did he have a valve adjustment? I say pull the heads.

 

[GypzRogue]

I would add no knock gas. What did the shop do to it when it was in there? Did he have a valve adjustment? I say pull the heads.

Actually, I think all they did was replace the rocker cover gaskets, which could have left the valves out of adjustment. I'm gonna check the primary oil and chain first, but it's a pretty heavy knock.....then pull the heads like you said. It does sound more like it's coming from the top end though. He thinks they probably ran the crap out of it on their 125+ mile test ride!! I really hate going behind someone else's work.....thanks for the suggestions though!

 

[Brew]

You might want to check valve train adjustment, there's posts on here how to do that... Just saying...