Jump to content
Sign in to follow this  

Yoshimura rs4 or fmf 4.1 for 2010

Recommended Posts

I was wondering if anybody has tried out the fmf 4.1 and a yoshimura rs4 and if so how do they compare? Im getting a 2010 and am looking for a new system, I have the fmf on my 09 and love it but it would be nice to hear the yosh pipe is better, it's a lot cheaper.

Share this post


Link to post
Share on other sites

I cant answer for the performance of the 2 for the 2010 but I will say that Yoshi has a very good track record for putting out one of the best performing pipes out there. I have used them on 07 and 08 YZ250F's and they (IMHO) are the best performance from low RPM to high.

My experiance with FMF is they are loud and seem to move the power around more than deliver more power everywhere. Also every one that I owned fell apart after about 6 months.

I dont think you will be disappointed in a Yoshi exhaust.

Share this post


Link to post
Share on other sites

I had a FMF mega bomb header and 4.1 exhaust on my 2010. Not 100% sure I had it jetted correctly, but it added some more top end once I changed the main jet (think it was main).

Biggest thing to keep in mind is that if you go Ti they don't last as well as a steel system.

If I get a system for my kx it will be Yoshi

Share this post


Link to post
Share on other sites

Thanks guys, That's what I wanted to hear. I have had the same experience in the durability department with my 4.1, they don't last very long. Yoshimura it is then.

Share this post


Link to post
Share on other sites

i thought the stock exhaust was good on the 2010. thats why i havnt baught a pipe. i think the yoshi website says it pipe only adds 0.5 hp. if you look at the dyno chart it has with its pipes

Share this post


Link to post
Share on other sites

I feel the stock pipes are very restrictive, personally I felt the fmf was a huge improvement over stock which is very similar to the 10's stock pipe. Im excited to see how the rs4 performs.

Share this post


Link to post
Share on other sites

I have a 09yz250f and im buying the 600$ youshi rs4 with the carbon tip, its the cheapest, and barns119 is correct it'll only add about .5hp, but I still like youshi and im still gonna get one for my bike, I like the sound and im sure ill notice a little difference

Share this post


Link to post
Share on other sites

I have had both bikes and if i remember correctly the fmf muffler will actually bolt up on a 2010, leaving you only a head pipe to purchase...you may want to look into that somewhat and save some $$

but i too have only heard good things on the yoshi

Share this post


Link to post
Share on other sites

i thought the stock exhaust was good on the 2010. thats why i havnt baught a pipe. i think the yoshi website says it pipe only adds 0.5 hp. if you look at the dyno chart it has with its pipes

Funny thing about what pipe manufacturers claim their pipes put out HP wise. I believe Yoshi in theirs. .5 HP is a considerable increase in power on a bike that puts out between 34-36 HP at the rear wheel. I remember one of the first aftermarket pipes I bought claimed 3 HP and in reality it was about.03HP on the Dyno at the rear wheel.

Share this post


Link to post
Share on other sites

For me, it wasn't really about a major power increase it was just a little better pull up top. Seemed to rev through the curve better / more productive.

Share this post


Link to post
Share on other sites

I have both. Fmf 4.1 slip on and full yoshi ti system. Put the fmf on for last national enduro for spark arrester it had more bottom than yosh. It then fell apart at the race loud as hell. Repacked it and only got five enduros out of it. Yosh has better even pull thru out power range and has lasted an enduro season with out repack. Yosh sound is much easier on my ears and everybody on my minute

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×