FMF 4-Stroke muffler tips #dirtbike #fmf #ktm

[kylestewart]

For all you kids out there. LEAVE IT IN. 250cc will not benefit any with open exhaust. Youll just get more riding areas closed down do to excessive niose.

[philp]

"Any type of tool" me trying to pop a clip ring with a sledge hammer

[jordanonofer]

Love J's vids. Easy to follow. He explains things easy

[Wyco_Hill_Killers]

That’s the most legal way bro could find to show people how to take the spark arrester out 😂

[tyladube]

I actually like the screen in there it prevents kids from dropping rocks down the pipe which is hard to remove from the exhaust

[ocker]

My buddy's bike shoots flame, I don't think he's burnt down the woods yet😂😂

[LS]

As soon as he said “back pressure” I knew this video was full of it 😂

[ChiTownGuerrilla]

I trust FMF to know what they're doing, and that it serves a purpose. Leave It in, any power gain already happened from the aftermarket exhaust.

[jakethesnake]

When I hear people say “engine like a little back pressure” it makes me cringe... scavenging and back pressure are two different things and no engine wants back pressure

[nhbountyhunter]

Can everybody agree a motor is an air pump (you all better say yes). More in, more out is the simplest way to prove back pressure is bad. It is much more complicated, I know. When goin out if you speed up the air faster then goin in then you can got more in (scavenging). If you straiten the flow you can get more out buy (scavenging + resistance too). Bigger out then in (but not too big) will help. Too big can cause low pressure spots actually sucking in air from the tail pipe leading to opposing forces. You can do simple test at home with a small fan, cardboard, ducting and tape. Do it your self. See if you can increase air velocity from a fan using those materials. Its fun and you just may learn something.

[astontoftero]

the exhausts are designed to be run without the baffle, i worked at sc project for a little bit designing full race systems, we always shipped them with the baffles, but they were never intended to be left in there, if anything the increased resistance in pushing out the exhaust, takes away from the air and fuel you can push into the cylinder, meaning you get a weaker explosion, which means less power, the optimal back pressure is without the baffles, with them you're just choking down the engine

[llecki]

That’s the cleanest spark arrestor ever! It’s brand new 😮

[JoltyFN]

It Is Not A Insert It Is Not To Start The Forest On Fire 😂

[bannedbrothers]

Thanks for showing us. As anyone knows, trail riding needs spark arrestors but they will clog so maintenance is key. Remove and clean the screen often to get the best performance.

[sendit]

Beneficial back pressure is a myth. Maximize exhaust velocity while minimizing exhaust pressure.

Any amount of pressure seen at the back side of the exhaust valve is lost hp and retained heat. People mistake exhaust velocity for backpressure, velocity is what creates the scavenging effect every combustion event.

The only time "back pressure" (Drive pressure) is ok is with turbo vehicles, and the ideal drive pressure is 1:1 with MAP.

[tonymetallicaify]

Back pressure is a 2 stroke thing, 4 stroke have little effect on back pressure especially with the new fuel injection system

[ashtynroney]

Sir Smokey the bear told me to throw those away😂

[moabsingletrack]

People who think backpressure is a good thing don’t actually know anything about how exhausts work. Backpressure is always bad. The whole point of an exhaust is to get the gasses out as quickly as possible for the next cycle. Exhaust velocity and scavenging is what matters.

[ThePolishRifle]

That’s a spark arrestor - required for public trail riding in most states… and the police regularly do checks, by sliding a stick down the pipe. If they don’t bump into one (the basket looking thing) you’re getting a big fine

[DWBmotorsports]

Needing Backpressure. The most common myth ever repeated in the exhaust world.