exaust question (please help)

[steve_cirillo]

first off, does a wr426f have a spark arrestor? im assuming yes. so with that will a stock wr can fit on a yz? please help thanks a whole bunch.

ps it's a little different here in the wr forum than in the yz forum... kinda nice

[simon@vic]

i think yes and yes.

[fershy]

I think no and yes. Yes it will fit. No it is not spark arrested.

Does the WR cannister have any markings detailing the type of Spark arrestor inside? I don't recall seeing anything on my WR stocker stating it is a spark arrestor. Incidently the OEM muffler has been shelved for a long time. It is a Canadian version though so I am not sure about the US version.

fershy

[JSanfilippo]

The US model WR 426f have a USFS approved spark arrestor in the stock pipe. The downside is the spark arrestor design is restrictive and with the baffle out it is just about as loud the YZ pipe.

[steve_cirillo]

thanks for the info. so the us model has the spark arrestor but is restirctive. with the baffle out it's as loud as the yz. so i guess my question is, does the stock yz pipe meet the sound requirement? it is green stickered.

[GCannon]

The YZ and WR pipe are interchangeable but they are not excactly the same the upper mount to the sub frame has a differnt bushing arrangement but can be adapted easily. the stock YZ pipe works well but is VERY LOUD do not expect it to pass any sound tests in stock form. the WR pipe with the baffle out is still quieter than the YZ pipe but may or may not pass any sound tests

[JSanfilippo]

The YZ and WR pipe are interchangeable but they are not excactly the same the upper mount to the sub frame has a differnt bushing arrangement but can be adapted easily. the stock YZ pipe works well but is VERY LOUD do not expect it to pass any sound tests in stock form. the WR pipe with the baffle out is still quieter than the YZ pipe but may or may not pass any sound tests

YZ pipes generally test at 102-105 db and uncorked WR pipes generally test around 100 db. You can put the PMB spark arrestor and the silent insert on the YZ pipe but the performance goes to crap...I think that set up tests arond 95 db. The Q2 is the best compromise between sound and performance IMHO