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Slightly different YZ exhaust on WR question

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Which has probably been asked but I couldn't find an answer...

 

I have a stock WR exhaust that is bored out from the PO and pretty loud.  Would like to quiet it down and not suffer much for power loss so I'm looking at going to the YZ exhaust.

 

1. Is it worthwhile to get the full exhaust (including header) off a YZ to get the most benefit?  Not sure if there is a difference between YZ/WR header flow/design.  

 

2. Does the YZ exhaust have an OEM spark arrestor?  If not I assume I can modify something to fit?  I'll need one for some future group trail rides.  

 

Thanks.

 

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Which has probably been asked but I couldn't find an answer...

 

I have a stock WR exhaust that is bored out from the PO and pretty loud.  Would like to quiet it down and not suffer much for power loss so I'm looking at going to the YZ exhaust.

 

1. Is it worthwhile to get the full exhaust (including header) off a YZ to get the most benefit?  Not sure if there is a difference between YZ/WR header flow/design.  

 

2. Does the YZ exhaust have an OEM spark arrestor?  If not I assume I can modify something to fit?  I'll need one for some future group trail rides.  

 

Thanks.

 

How does somebody bore out the muffler?

 

1) I did a search of this forum (since I haven't added a stock YZ exhaust system to either of the WR-250Fs I've owned), and guys who have done it claim more power at all engine speeds, AKA "more power everywhere".

 

I've read that 2001 WR-250F header pipes are a little bit smaller in diameter than 2001 YZ-250F header pipes, but, I'm taking their word for it since I haven't measured them, myself.

If I were riding a 2001 WR-250FN and were going with a 2001 or 2002 YZ-250F exhaust system, I'd probably do the whole thing.

 

2) No YZ muffler comes with a spark arrester that I can ever remember.

You can add them by buying things like these:

 

http://www.promotobillet.com/catalog/product_info.php?products_id=42

 

Of course, as always, there's a chance you will need to do some carburetor changes (jetting changes) if you switch to something that's very different from what you have now.

Edited by YZEtc

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"Bore out" was a poor choice of words.  The pea shooter was removed and I'm guessing there probably isn't much packing left either.  

 

Have also read about "more power" but was trying to determine what, if any, differences there were in the header alone since I see a lot of the slip only sections for sale.  

 

$135 for a spark arrester....yeesh.  That in combination with buying the exhaust, I think I'd rather just go with an FMF or equivalent.  

 

Thanks for the reply.

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ProMotoBillet....offers another $40 alternative for the '01 WR250F for a spark arrestor insert.

 

http://www.promotobillet.com/catalog/index.php?cPath=46_88

 

Sounds like they took out the restrictive insert, but didnt replace it with anything.  You might also look at repacking the stock muffler to quiet it down a bit.

Edited by SilvFx

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