What Exhaust should I buy?

I have a 2005 Yamaha YZ250 2 stroke.What exhaust should I buy?

Anybody?

Stock is good, I like SST and Doma for mid and WOT

I just ordered a FMF Gnarly but I tinker around in the woods.... Slap a CF pipe guard on any your golden!

Thanks!!!

Dylan, check the YZ FAQs for a pipe shootout and info: http://www.thumpertalk.com/forum/showthread.php?t=344959

After checking this thread, I got a DEP and am pretty happy: http://www.thumpertalk.com/topic/1039387-yz250-dep-first-ride/

I tested an FMF fatty at motocross and it worked reasonably well, more mid, and less linear than my DEP exhaust. I rode a PC equipped yz250 and it felt quite week compared to my DEP. I tend to start at the apex of my turns in the bottom to mid range and so the PC didn't work at all well for me. that's my 2 cents ...

If I was riding track/MX, I would definitely get a raw pipe, to better-represent the 2-stroke world with a phat expansion chamber.

I think you need to buy every single pipe made and test them all out yourself, on your own bike & track. Then you keep the one you like the most!

 

(and sell me the other pipes for a much reduced rate!) :p

I have an 05 with a DEP with stock muffler and I really like the power delivery. I'm an intermediate MX rider and it has good low end, great mid, and decent over rev.

Edited by Bremer120

I have an 05 also. Had a fmf gnarly with stock silencer on it but signed off way too early for me. Went with the fmf sst now. Not as much bottom but pulls like hell from mid to top. Mainly woods riding. B vet harescrambles. Hope that may help ya.

hard to beat stock,

 

sst is crap, ive had two on 2 different bikes, they are hard to tune for max power, and when you do get the jetting past rich the bike runs to lean

 

steve from moto814 porting wrote this, and after what ive experienced first hand i completely agree

 

 

 

The FMF SST pipe is an amazing pipe.

Why is it amazing? Because in just about every case, it will work WORSE than the stock pipe that came on the bike.

The SST uses a restrictive reverse cone and pressure bleed to intensify the return wave and lower the initial flow out the stinger section of the pipe. What that in turn does is increase piston crown temperatures and make jetting difficult at best.

Now increased piston crown temperatures can be compensated for to some extent with richer jetting. But, by doing that you are defeating the purpose of the pipe, and negating any power gain you may have gotten from the pipe in the first place. Why are increased piston crown temperatures bad? Well, in some cases they are not. You see most bikes are jetted horribly rich from the factory, and raising the piston crown temps in this case will "fool" the engine into thinking it is jetted leaner than it is. Which will in some cases improve power. But in most cases, it will just cause slightly better throttle response and an increase in the spooge out the back of the pipe.

After all that you may be thinking: "well this doesn't sound so bad, why are they saying this pipe is no good?" Good question. Here's the answer. Because of the restrictive nature of the pressure bleed from the pipe, it does not evacuate as efficiently as it needs to. This combined with the piston crown temperature increase yeilds jetting that is too rich. So now you have a pipe that "fools" the engine into thinking it is leaner than it really is, but also makes it much richer than it was previously. Here in lies the second problem. It makes jetting a nightmare. If you jet it by feel, you will be jetting richer, and compounding the too rich condition even more, making the bike run like a slug. If you jet it leaner, you will be increasing piston crown temperatures even more resulting in an engine siezure. Catch-22 anyone?

 

 

 

stock is good, keep it if its in good shape, cut the stock silencer down to 10 inches, it will be like a pc 304 clone, stock is similar to the PC 304 in terms of core size etc. stand to reason a shorter stock silencer is alot like a pc 304.

 

fatty is a good mid-up pipe

dep seems tobe amazing from bottom to top

pc is good mid-up

 

pc 2, doma and gnarly are lowend pipes.

Edited by adam8781

hard to beat stock,

 

sst is crap, ive had two on 2 different bikes, they are hard to tune for max power, and when you do get the jetting past rich the bike runs to lean

 

steve from moto814 porting wrote this, and after what ive experienced first hand i completely agree

 

 

 

 

 

 

stock is good, keep it if its in good shape, cut the stock silencer down to 10 inches, it will be like a pc 304 clone, stock is similar to the PC 304 in terms of core size etc. stand to reason a shorter stock silencer is alot like a pc 304.

 

fatty is a good mid-up pipe

dep seems tobe amazing from bottom to top

pc is good mid-up

 

pc 2, doma and gnarly are lowend pipes.

how long should the canister be? (Without the tip) It comes out to about 7.5" without the tip, sound right?

Edited by Fasz Kalap

how long should the canister be? (Without the tip) It comes out to about 7.5" without the tip, sound right?

 

http://www.allthingsmoto.com/forums/f-30/yz250-pipe-silencer-tip-19073/

 

I was wrong, 13 inches, im not sure where it was measured to.

 

I would simply cut it back this far. i thought it was 10, might be 13? maybe the r304 was the 10 inch? but it had a different sized core compared to the 304 and oem

 

s1600_IMG_6521.jpg

 

s1600_IMG_6521.jpg?1365975727

or if you want to make a shorty, people have done that to and reported it worked just fine

 

post-76521-0-20281500-1363283129.jpg

.

image.jpg

Edited by Bremer120

I just chopped mine a few weeks ago. May have went a little short but time will tell. I think overall length isn't far off of a shorty.

how much louder is it?

how much louder is it?

Haven't ran mine yet. I'll let you know

edit.

Edited by Fasz Kalap

8.5" shell

Edited by Fasz Kalap

8.5" shell

 

 

get a good sound clip of the bike warmed up and revving if you can.

 

 

How short does it have tobe to just barely get rid of the second silencer mount?

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