2.1 or FMF Shorty?

DawsonBMX54
Edited Date/Time 6/22/2021 11:00pm
Hey guys, I have a 2021 YZ250 and I am looking at getting a full exhaust system for it.

I have decided I want the FMF Fatty header because I don't want to gain power and lose it somewhere else, I just want it to be stronger across the whole RPM range.

So my question to you guys is, which silencer should I go for? The shorty or the 2.1?

Pros and cons to each?

Also did you guys re jet your bikes after installing a system?
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chump6784
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chump6784 6/21/2021 1:52pm
6/21/2021 1:52pm
Personally I'd go with the HGS or DEP combo over the FMF. HGS makes more bottom and mid than the DEP but DEP pulls better up top than the HGS. My preference was the HGS with the HGS short silencer. I could lug that set up more and used less clutch. Both are better than stock.
Now to answer your question, it depends on what power characteristic you want. The shorty will emphasise bottom to mid power with a more snappy characteristic, the 2.1 will make a smoother powerband through the bottom and mid with more top end pull
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JBecker 72
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JBecker 72 6/21/2021 5:03pm
6/21/2021 5:03pm Edited Date/Time 6/21/2021 5:04pm
I really like the 2.1 exhaust. It just looks right and sounds very nice. Major size difference between this and a shorty. The 2.1 looks like a four stroke exhaust.

As fas as jetting goes I believe I went up one size on the main but left the needle and pilot stock.


cloud41
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cloud41 6/22/2021 4:49am
6/22/2021 4:49am
I have both mufflers on 2017 yz250s. The 2.1 sounds terrible in comparison to the shorty. It is choked up and quiet. The shorty sounds amazing and looks better in my opinion, also cheaper.
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Speeddemon73
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Speeddemon73 6/22/2021 5:03am
6/22/2021 5:03am Edited Date/Time 6/22/2021 5:16am
Probably not the answer you're looking for but in my experience, you are going to get more of what you are after by having your head cut and a port job done. For the same price as a full exhaust system for your bike, you can have your head cut for the fuel you want to run and your cylinder ported and be making way more power than any exhaust is going to add. Also, having run FMF exhausts on many different two-strokes both 125 & 250 their systems don't seem to offer much more power over stock. The best gains I have seen in the seat of the pants feel have been from Pro-Circuit. If I were you, I would take my head and cylinder, ship it to Pro-Circuit and have them work their magic. They usually give discounts on exhaust systems too if you want to buy one at the same time they are doing work on your stuff. At least in my experience, they offered me a 20% discount on a full exhaust system for my 250 when I had them cut my head and port my cylinder.

But to answer your question, if the tracks you ride at are tight and have lots of low-speed sections get the shorty. If the tracks you ride at are higher speed and really don't have a bunch of tight sections, then the longer canister on the 2.1 will give you some more over-rev and let the bike wring out longer. With exhausts, it's a give and take. You are either sacrificing top end and over-rev for bottom or bottom end and torque for more top end. This is why I suggest a head and port job because the gains are usually across the board. If you have it done by a reputable company they usually fix any big issues with power delivery making the bike pull across the board.

Don't base your decision on sound, base it on performance. Because a cool sounding exhaust isn't that cool when it doesn't do diddly squat on the track.
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AH387
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AH387 6/22/2021 5:57am
6/22/2021 5:57am
It's all in what you are wanting from the bike. The 2.1 gives you a slightly wider powerspread. The Shorty is always barky but maybe a bit more narrow of a window. I have the Shorty on my 125, but suggested the 2.1 to my buddy for his 150SX. You really can't go wrong with either as the Shorty has been around (and liked) forever. And the 2.1 just has a bigger body, less edge to the sound and a slightly longer, smoother delivery.
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Rjk31
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Rjk31 6/22/2021 8:50am
6/22/2021 8:50am
What about the 2.1 shorty?
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AH387
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AH387 6/22/2021 9:46am
6/22/2021 9:46am
Rjk31 wrote:
What about the 2.1 shorty?
Good point. I was talking about the 2.1 Shorty in my above post, to be clear. I just assumed those were the 2 in question.
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mattyhamz2
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mattyhamz2 6/22/2021 1:40pm
6/22/2021 1:40pm
cloud41 wrote:
I have both mufflers on 2017 yz250s. The 2.1 sounds terrible in comparison to the shorty. It is choked up and quiet. The shorty sounds amazing...
I have both mufflers on 2017 yz250s. The 2.1 sounds terrible in comparison to the shorty. It is choked up and quiet. The shorty sounds amazing and looks better in my opinion, also cheaper.
I'm glad I'm not alone in thinking this. I HATE the sound of the 2.1
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DawsonBMX54 6/22/2021 2:55pm
6/22/2021 2:55pm
Speeddemon73 wrote:
Probably not the answer you're looking for but in my experience, you are going to get more of what you are after by having your head...
Probably not the answer you're looking for but in my experience, you are going to get more of what you are after by having your head cut and a port job done. For the same price as a full exhaust system for your bike, you can have your head cut for the fuel you want to run and your cylinder ported and be making way more power than any exhaust is going to add. Also, having run FMF exhausts on many different two-strokes both 125 & 250 their systems don't seem to offer much more power over stock. The best gains I have seen in the seat of the pants feel have been from Pro-Circuit. If I were you, I would take my head and cylinder, ship it to Pro-Circuit and have them work their magic. They usually give discounts on exhaust systems too if you want to buy one at the same time they are doing work on your stuff. At least in my experience, they offered me a 20% discount on a full exhaust system for my 250 when I had them cut my head and port my cylinder.

But to answer your question, if the tracks you ride at are tight and have lots of low-speed sections get the shorty. If the tracks you ride at are higher speed and really don't have a bunch of tight sections, then the longer canister on the 2.1 will give you some more over-rev and let the bike wring out longer. With exhausts, it's a give and take. You are either sacrificing top end and over-rev for bottom or bottom end and torque for more top end. This is why I suggest a head and port job because the gains are usually across the board. If you have it done by a reputable company they usually fix any big issues with power delivery making the bike pull across the board.

Don't base your decision on sound, base it on performance. Because a cool sounding exhaust isn't that cool when it doesn't do diddly squat on the track.
I appreciate the honesty and feedback,

To be honest I'm not wanting to really tear apart my engine and have it sent off (at least during riding season) maybe I will consider that in the off season when I can't ride anyways!

I am thinking I am going to go with the shorty due to the fact most of the tracks I ride are more tight turns then open straights.

With the fatty and shorty combination do you recommend doing any adjustments to the jetting like another guy said on here when he switched to the 2.1?
DawsonBMX54 6/22/2021 2:57pm
6/22/2021 2:57pm
Rjk31 wrote:
What about the 2.1 shorty?
AH387 wrote:
Good point. I was talking about the 2.1 Shorty in my above post, to be clear. I just assumed those were the 2 in question.
I am going to be honest,
I didn't even know FMF made a 2.1 shorty lol, I was torn between the standard 2.1 or the standard shorty. I think I am going to go with the shorty though because most of my tracks have a lot of tight turns and I tend to shift sooner and carry a taller gear to help keep momentum so I am not absolutely strangling the bike.

I appreciate the feedback and help though!
DawsonBMX54 6/22/2021 3:00pm
6/22/2021 3:00pm
JBecker 72 wrote:
I really like the 2.1 exhaust. It just looks right and sounds very nice. Major size difference between this and a shorty. The 2.1 looks like...
I really like the 2.1 exhaust. It just looks right and sounds very nice. Major size difference between this and a shorty. The 2.1 looks like a four stroke exhaust.

As fas as jetting goes I believe I went up one size on the main but left the needle and pilot stock.


Nice ride dude!

I didn't realize how much bigger the 2.1 is in diameter! I think I am going to go with the shorty though due to my tracks being more tight turns than long straights and I can always just grab another gear if needed!
DawsonBMX54 6/22/2021 3:03pm
6/22/2021 3:03pm
Just another question guys!

For those of you that have YZ250s what gearing do you run?
I am running the stock right now (14/50) and I am considering dropping the rear sprocket to a 49 tooth to give it more pull between gears (especially if I get the shorty to add some more grunt)
Any thoughts?
AH387
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AH387 6/22/2021 8:29pm
6/22/2021 8:29pm
DawsonBMX54 wrote:
I am going to be honest, I didn't even know FMF made a 2.1 shorty lol, I was torn between the standard 2.1 or the standard...
I am going to be honest,
I didn't even know FMF made a 2.1 shorty lol, I was torn between the standard 2.1 or the standard shorty. I think I am going to go with the shorty though because most of my tracks have a lot of tight turns and I tend to shift sooner and carry a taller gear to help keep momentum so I am not absolutely strangling the bike.

I appreciate the feedback and help though!
My bad lol. I've only seen a Shorty 2.1 in person but probably because it was only on 125/150s. But even the shorty 2.1 is quite a bit larger than the standard shorty. And like I mentioned, going with the standard Shorty is not a bad idea. I believe it's a decent amount cheaper too. I think you'll like it.
AH387
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AH387 6/22/2021 8:37pm
6/22/2021 8:37pm
DawsonBMX54 wrote:
[b]Just another question guys![/b] For those of you that have YZ250s what gearing do you run? I am running the stock right now (14/50) and I...
Just another question guys!

For those of you that have YZ250s what gearing do you run?
I am running the stock right now (14/50) and I am considering dropping the rear sprocket to a 49 tooth to give it more pull between gears (especially if I get the shorty to add some more grunt)
Any thoughts?
I feel like no one really drops the rear sprocket on those bikes. I left mine stock, when I had one. MXA suggests 51, which I know that's always the joke w/ MXA. Still, I think since that bike has somewhat of a linear build up (compared to the KTM at least) it might feel gappy down low if you go to a 49. Maybe consider the 51, the exhaust, vforce and the heavier gytr flywheel, which I always thought was the hot set up.
mattyhamz2
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mattyhamz2 6/22/2021 9:55pm
6/22/2021 9:55pm
DawsonBMX54 wrote:
[b]Just another question guys![/b] For those of you that have YZ250s what gearing do you run? I am running the stock right now (14/50) and I...
Just another question guys!

For those of you that have YZ250s what gearing do you run?
I am running the stock right now (14/50) and I am considering dropping the rear sprocket to a 49 tooth to give it more pull between gears (especially if I get the shorty to add some more grunt)
Any thoughts?
I ran stock gearing on mine. I liked it the way it was. Stock pipe, stock gearing, no motor work other than complete OEM rebuild. I loved that bike and still regret selling it after 2 years.
PTshox
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PTshox 6/22/2021 11:00pm
6/22/2021 11:00pm
I had a 2.1 with a FMF fatty pipe. I preferred the shorty over the 2.1. Rev'd quicker.

As far as motor mods... If you are going to do anything send the head and cylinder to Ken Oconner racing. He will shave material off the base of the cylinder (lowering the ports) and do a head mod to compensate. The 1999 on up YZ motors don't really need a bunch of porting. Lowering the ports makes it pull off the bottom better.. then shift. )

I also had a Pro Circuit works pipe for that bike. It was horrible in my opinion. I actually threw it away it was so bad. I mean it ran terrible with it. Swapped it out while testing back to back with the FMF fatty and once the fatty was back on it ran great. No other changes.

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