Rattle in exhaust...

[TRHOD]

Hey all,

Well, after gloating so much about the Ol' green 450, I've got my first non-stupitidy problem.

Seems like I've got a rattle in the exhaust. I've had someone tell me that it is common with the stock exhaust on this bike to have baffles loosen up. Is this true? If so, he thought it might me possible to mig weld it. Is that possible?

I haven't really got a chance to look at it yet. I was hoping I had a bolt or clamp loosen on the heat shield and it would be a simple fix.


I'm really hoping to keep the cost of this down as I'm somewhat in the market for a new bike. Meaning, I'd like to have a rubicon, but don't really have the funds right now.

Thanks for your help.

Blessings,
TRHOD

[MuddnMason]

Have you checked the obvious heat shield rattle?

[TRHOD]

Phil,

No, like I said I haven't really looked into it yet, but an hopeful it is just a loose bolt or clamp on the the heat shield. I was just wondering if others had problems with the baffles loosening up, like this guy had said.

Blessings,
Ted

[Jake]

Yes, it is definately common. The noise is very similar to the heat shield noise that you suspect. If it sounds like it's coming from inside the pipe, and the shield over the pipe is tight, get out your screwdriver. Turn it around backwards though, hold the tip, and use the handle to tap the shields up by the engine and over the muffler. If you have a loose one, you won't get a rattle, but rather one single one of the "tinks" that add up to a rattle. Also try along the bottom and side of the muffler. Almost always you'll find it like this. If you can't, then it's almost surely inside the muffler.

[TRHOD]

Thanks for the info, Jake.

I'm gonna give this a shot when I get a chance.

Couple of caveats to this. The rattle seems to show up after I have accelerated hard or ran the bike wide open for a little bit. I've notice when I'm plowing, I don't have a rattle for the first few houses that I plow. It seems to show up when I run the bike wide open for 2-3 blocks getting from one house to another. Also, with in the past year I have changed to a high flow air filter. Ever since I have done this I have had backfire pops when decelerating after a running it wide open, or when using the engine as an engine brake while going down hill.

I'll keep you posted.

Blessings,

[Jake]

It's lean in the pilot circuit. I'd bet you that adjusting that will solve the backfire issue.
You've added a high flow filter and nothing else? That is worth about an eighth of a turn out. Going out on a limb, I'm guessing that you'll find the rattle to be in the pipe as well, which means the insides are slightly worn, which means that pilot will want another 1/16 to 1/8 of a turn out. Add to that you're edging towards lean across the board because it's cooler out than the "expected riding temperatures".

The pilot jet is the one directly at the bottom of the carb, it looks like a small flathead screw driven straight up into the carb in a "coutout notch" in the float bowl. Left and right directions are confusing when you're upside down and backwards, so I'll say that this screw is actually a needle that is used to calibrate, or partially plug the pilot jet oriface. You should "unscrew" that screw to richen the mix at idle. And obviously, make a visual note as to where it started, in case I'm off base, that way you can set it back exactly where you started without having to actually to through the steps of setting it up.
There's a picture in the service manual, and I believe that if you still have your owners manual there are instructions and illustrations to direct you to this jet in there as well.

[TRHOD]

Thanks again Jake,

I'll play with the pilot in the carb next week when I check out the exhaust rattle.

Yes, the only mod I did was to add an Amsoil high flow air filter. I've changed the plug, but I stayed with the oem plug.

Blessings,

[TRHOD]

Just to follow up with this thread and but it to bed, I FINALLY had a warm day today to work on the bike. I was able to get an exhaust for the bike (thanks tallyforeman).

When I pulled my old exhaust pipe off it sounded like the inside had glass rattling around. I was able to change out the exhaust pipe without any problems

I adjusted the pilot screw out 1/4 turn OUT (thanks for the help on this Jake). It seems like this has taken care of the backfiring/popping, but it was warm today. So I will have to see how it is when it gets colder. Might have to make some more minor adjustments.

If anyone has to adjust the pilot screw, it is a tought little bugger to get to. After a while statagising, I finally figured out the best way to get to it was to go to the exhaust side of the bike, pull of the plastic side panel. You have pretty good access to the screw like this. You'll need a small flat-bladed screwdriver.

Hope this will help someone, someday.

Blessings,