What did I screw up?

[langow]

I replaced my exhaust donuts this spring. Took it out for the first trip to the UP today and each time I started it up after a trail stop, it got louder. This only lasts until it's warm, then it quiets up and sounds completely normal and runs great. What did I forget to tighten up? Or? Looking for ideas.

 

[LJ 452]

Did you remove and check all four of the headers/flex pipes? How about the Y-pipes themselves? Assuming everything on the flanges what tightened it sounds to me like you may have a cracked flex pipe.

 

[Bigblue1]

Sometimes the brackets fit loose around new donuts. I had to grind mine down just a bit for a tighter fit. Its explained well on this site.

 

[mr. shide]

maybe its just idling high to warm itself back up?

 

[langow]

Did you remove and check all four of the headers/flex pipes? How about the Y-pipes themselves? Assuming everything on the flanges what tightened it sounds to me like you may have a cracked flex pipe.

This is what I'm thinking. Something is definitely broke. Everything appeared to be ok when I replaced the donuts. I just changed them to be proactive but now I definitely have a bigger issue. It still eventually quiets up and sounds normal, but even after a 5 minute trail stop, it sounds horrible. I'll tear it back apart this week and see what's going on. Not what I was looking to have to do.

 

[kinger]

I just had mine fail this morning or so I thought. Pulled it all apart and one clamp bolt backed all the way out and the clamp was loose. gasket was still good shape but it was LOUD, simply replaced the clamp and bolt and all fixed. Other 3 were tight. No idea what happened.

Hopefully yours is that simple.

 

[langow]

I just had mine fail this morning or so I thought. Pulled it all apart and one clamp bolt backed all the way out and the clamp was loose. gasket was still good shape but it was LOUD, simply replaced the clamp and bolt and all fixed. Other 3 were tight. No idea what happened.

Hopefully yours is that simple.

That would be nice. I never seem to get that lucky though. LOL

 

[aceltx09]

If its that bad/loud you should be able to spot a problem when you take it apart

 

[langow]

Finally had a chance to tear it down and see what was going on. I couldn't believe what I found. All 4 bolts that hold the flex pipes to the block were completely missing from right 2 cylinders! WTF? The only thing I can figure is I must have snugged them up, then stopped for a beer break and forgot to torque them down.

Oh well. Lesson learned I guess. No drinking until the wrenching is done. I found 2 of the missing bolts lying in the access panel under the motor. Flex pipes still look good. I'll just have to get 2 new bolts and I'm good to go.