FMF pipes. SST vs Fatty

[beaner]

04 RM 125.
I've been using an SST for the last few years, and I love the way it pulls in the mid. It feels so much stronger than stock, it's not funny. I also got a great deal on a Rev pipe, used it for a few weeks, but it's a little too thin in the mid, and a little too screamy on top. If I didn't have the SST I'd definitely take it over stock, but it seems a little weak in the midrange for my style. Does anybody have experience with a Fatty vs an SST? Just looking for a little more low to mid, and wondered if that's the way to go?

[dogger315]

I've used both on 250s and from my experience and from what I've been told as well, the SST
is going to be a better top end pipe - excellent for tracks with long straights.  The Fatty is more
of an all rpm pipe with a healthy hit and better than stock over rev, but it will give up before the
SST.  I ran SSTs and Ti-2s on my case reed CRs because they needed all the help they could get,
and it still wasn't near enough.

dogger

[Stusmoke]

If its low to mid you're after, I'd look into a gnarly pipe. But you will sacrifice some top end.

[arnego2]

Are you flexible enough to try Doma? I got a complete sytem of ebay and with the JD kit I'm happy and can recommend those.

[Factory-MX]

From all the 125s I raced back in early 2000's (ended with 03 RM125) there was never really any pipes that gave you bottom end. The best pipes for the zukes' were the Bills pipes. I am not sure if they are still around though... The SST is the best on the one 2 fivers I would say. Just keep your momentum up in the turns and it will out perform the rest.
  Vortex ignition would give you added power all around...including the bottom end. If you can find a used one off ebay or something it would be worth every penny to compliment the pipe.. 

[beaner]

Thanks for the info.

arnego2, I would try a Doma, but we don't see them over here much.

I posted this just after I ran our club's annual 1 hour moto. I had a lot of time to think, and after a while I was getting tired, and looking for an easier ride, and a little low end power. Since then, I've considered a 144, some porting, head milling, reeds, and even advanced the timing a bit before practice last night. Advancing the timing gave me all the bottom end I could ever ask for. It felt like my buddies YZ 144. It also took everything off the top that I gained on the bottom, and I realized that the hit, and top end power was my favourite part 
So I think I'll ride out the season, replace the piston and rings, and try the Boyesen pro reeds I bought on ebay last night. The originals are still in the bike, so they might make a difference.
You're right, the SST is a kickass pipe. The mid and top end power is killer.
BTW, in the 1 hour, I holeshoted against a gate of 450's 

[arnego2]

Yeap I know, occasionally I browse ebay and have a look out for pipes. OEM, Doma, PC are my favourites. The Doma pipe is huge compared to the others. You need to look for those quite often before a good deal shows up. But pipes are articles which get wasted over time.

[Coop]

The last RM125 I had was equipped with a FMF Fatty and Bill's shorty silencer. It seemed to lack bottom end even after being completely rebuilt (top and bottom end).

[KX250]

Fatty pipe will hit harder on the top end and you will loose the pull out of the mid range.  At least I did on my KX250.  I do a lot of single track and like the Gnarly the best out of the FMF pipes. There used to be a company called spes pipes and they were really good all around.