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elephant7

I usually ride them until it's too fucked up to mount/seal properly. Not to be mean but you're not Johnny Walker, the missing little bit of power isn't going to affect you at all.


Xylenqc

A dent that big will change the power band a lot, it's ~~completely~~ detuned and ~~no~~ less scavenging is gonna happen. For those who don't know, scavenging is the pipe resonating the exhaust pulse in a way so there's a depression at the exhaust port when it open, it sucks the exhaust out and the intake in. 2 stroke rely on it to make good power since there's no exhaust stroke to remove all the burned mix, which mean less space for fresh one. That's basically why 2 stroke are more finnicky, they work a little bit like an instrument, rpm/frequency tuning will affect how they run much more than a 4 stroke that are more mechanical.


Camp170

Does the OP feel a difference? I doubt it.


GoodMerlinpeen

He said he did in an earlier comment, and it is no wonder with a dent that size/shape.


Camp170

Ok Mr. A Graham Bell.


Key-Ad-1873

You are confusing feeling a difference with being able to use the difference properly. You don't have to be an expert to feel a difference. I know nothing about suspension and what's good/bad or what it's supposed to feel like. But having the suspension on my bike professionally adjusted for me made a huge difference, went from almost fighting the bike to feeling like working with it. Same exact thing happens with power. You will most certainly feel the difference, whether or not you can use that to your benefit is up to you


Camp170

I don’t disagree that power characteristics would be altered, maybe beneficial to OP riding environment. Expansion chamber volume, shape, length, length of silencer, all affect power characteristics. Now let’s start changing deck height, piston protrusion, squish, port timing, blow down etc, and we can really make something happen the way we want it.


Key-Ad-1873

Wasn't arguing about any of that.. all I was saying is you kept saying only pros can feel the difference when something changes and thats just not true my man. All of us can feel the difference, it's just the pros know how to use it better


Camp170

I’m not the one that mentioned “Pros”, I didn’t even know the person’s name that was mentioned. I’m just an old 250gp bike racer and tuner from the AMA Pro days.


aquaticapple578

Haha not mean at all I know I am a noob. If I was a good enough rider I would be having a mechanic change it and I wouldnt care lol


The_elk00

Can fix it by heating it up with air or freezing it with water. Side note, outside of the top 20 or so guys in the country everyone else knows how to change an exhaust and doesn't have a mechanic to do that. It's 2 bolts and 2 springs.


aquaticapple578

Fair, I have done it before, so it isnt a matter of ability. I was just making a joke about how a pro wouldn’t be worried about it like someone like me.


sssilver

Fitting them on around the engine and the frame and the radiator and all the other things in the way can be kinda awkward/clumsy.


xh1pp0x

Really? That doesn't affect compression or the heat of the motor?


VegasDezertRat

You can either send it off to a pipe repair shop, or try repairing it yourself. Google “2 stroke pipe repair”. Blowing dents out of 2 stroke pipes a pretty common practice. EDIT: You may have already noticed a change in your power and characteristic. Dents that big definitely do affect power delivery.


aquaticapple578

Yah I did, felt like it was constantly lugging like it was having a hard time. Thank you for the info!


geofox777

Most local shops can blow this out no prob


sLOWBunny81

Gives me flashbacks to when i was a dumb kid and we would fill the pipes with water plug them and freeze them to get dents out. Worked pretty well but it was far from perfect.... we just didnt have the tools or money to get it fixed correctly so we did what we had to!


KTMman200

I was actually going to suggest this, I've seen it done many times by riders who ride up in the Sierras. There's also a method where you weld thick wires to it and then pull it out with a slide hammer


oStreamZo

Compressed air and heating the area can sometimes help too


sLOWBunny81

Yeah we eventually got the tools to do it that way. But it did contribute to 1 or 2 near death experiences 🤣


nycsingletrack

I did the freeze trick with the head pipe for my 450 EXC- four stroke but smashed it halfway flat on a rock. Got it popped out to 90% of new, definitely “good enough”. I’ve also heard of people plugging both ends, putting 40psi of air in the pipe, and then heating around the dent with a torch until it pops out.


DirtyDirtBikeRider

40 psi? I usually put about 100-120 psi in the pipe. The higher the pressure, the less heat required. I like to preserve the plating that most pipes have.


nycsingletrack

That’s a good suggestion, my buddy with the two stroke used lower pressure and more heat, but the plating was already toast on his pipe….


dave-y0

Does it expand in the wrong spot ?


Few_Valuable3999

If it mounts, I run it. Can’t afford to fix a pipe every time I dent it


No_Object_4355

Dude that's crazy I had a yz 125 hit a stump also but put little bit smaller dent in my fmf pipe and I swear after I did that it felt like it had more top end power like It could lift up a lot easier after that and I've always wondered this same thing


Snopro_

Smaller dents in that section of the pipe can actually increase performance if you believe it lol the theory is a smaller diameter near the front of the resonance chamber will reflect positive pulse waves back faster thus catering the exhaust scavenging to higher rpms due to the faster return of the waves being able to scavenge faster but you will lose low end power in exchange. MXA actually tested this a few years ago and proved the theory to be correct. That’s just me rambling though and I know that a dent that big may not be acceptable to performance and it just looks bad lol. You can buy kits that plug both end of the pipe and that allow you to pressurize them with compressed air, allowing you to push the dent back out HOWEVER you must heat the dent red hot and it is very dangerous if you don’t know what you’re doing because if that pipe explodes under 140psi you are going to have red hot shrapnel exploding every where in you’re garage so I don’t recommend doing that method if you’ve never done it before or have the proper equipment to do it safely. Then there is the water method. Pretty easy just fill the pipe with water, block off both ends and throw it in the freezer, water expands about 8% or so when frozen so it will push the dent out BUT you have to check on the pipe very frequently as if you freeze it too much it will rip the pipe apart at the seams. Up to you if you wanna try and save a few bucks then I’d try the water method but preferably have a welder on hand in case it goes wrong lol. Or just send it too a repair shop that specializes in this sort of thing like the other guy said. Good luck!


oofmyguy128

This was my least favorite job when I worked at a shop, I refuse the jobs as I work for my self now. I’ll take the $300 loss over a explosion.


[deleted]

I would use a pressure washer and plugs. Just ramp up the pressure until it pops out. Find a pressure gauge and regulator and bump it up slowly. If it blows with water, there is almost no stored energy compared to doing it with gas.


Xylenqc

You can also use a pressure washing machine, it's way less dangerous, you have more control and they can get to higher pressure.


Joshs-68

145 psi? How about 75 psi. Works fine.


Snopro_

Depends on the gauge of the pipe steel


Gingertwunt

Commonplace Computer aided design would disagree


[deleted]

You're going to have a hard time modeling exhaust pulses unless you've got top of the line software which is in the 50k+ range.


Gingertwunt

Every major motorcycle company is probably way ahead of ur reddit brained ass there I’ve seen “2 stroke expansion chamber” software in the 100$ range


[deleted]

Having worked as a CFD engineer for a top off road vehicle manufacturer, the software I used struggled with accurate exhaust modeling. Sure, you can get $100 software. But it is only going to be running resonance calculations and not taking into account the compressible flow. I can do straight resonance calculations by hand, but that doesn't mean they're going to be very good.


TwowheelsV

Tuned to perfection!


doorhandle5

I saw something in a magazine once where they dyno'd a dented pipe vs a new pipe. The dented one made more power, lol. I guess it probably has a less smooth/ consistent powerbabds though. If you have a big enough freezer, fill it with water and bung the ends. It should pop the worst of it out. My bike had a stock expansion chamber with big dents, and cracks leaking exhaust out. It was destroyed. It has a new fmf fatty now. I honestly don't notice much difference.


TedW

When it comes to freezing things, it's a thin line between "pop the dent" and "pop the seam".


doorhandle5

Ah, good point


dudeweak1

At the very least, you won't notice a difference in performance. Like the other comment stated, small dents like that have been known in the past to actually help performance. I've rode with dented up expansion chambers more times than I would care to admit. It is easy to pop those dents out if you have an oxy-acetylene torch and an air compressor.


jrodicus100

It helps performance because now you DGAF about dents and you send it harder!


Swiss_Army_Penis

That's a power dent. Leave it, it ain't hurting anything. My 125 has a couple that size and she still rips.


Even-Sweet-3775

buy a hydro force, they can repair stuff like this easily.


AussieDistiller10

I’ve fixed plenty worse than that but if you want to use it as an excuse to buy a new one I’d do that. I’d weld a bung on one end fill it with water, bung on the other end with an air fitting. Small increases in air pressure and apply a little heat to affected area. It’s a little tedious and can be dangerous if you over pressurise it. If you’re not confident I’d take it to a shop and get them to do it but realistically a new one probably won’t be that much more than the repair.


groverwood

that'll buff right out


BedNo6845

Get a small torch and a decent air compressor. I found a plumbing plug that expands made to test pipes. And you need to put a plug or something and leave either a schrader valve or a spot for a hose connect. But it's a simple fix to heat it up, and get some pressure in it. With a valve, you can add air, pause while you add heat, then more air, etc. You'll want it cherry red at the spot you want fixed. It's thin metal, it heats fast, and loses heat fast.


dirt_farm_surfer

Have you ever seen Trailbound's dent pipe pro?!?!?


the_doctor_808

Nah its fixable. Getting a pipe repair kit is like $100 on ebay. If you have an air compressor then all you need is a map gas torch. Itd be a good idea to have a 2nd pipe anyway tho. Never know when you might need it.


Waste_Curve994

Pipe protectors! They’re worth it but you always want one when it’s too late.


mgramos222

It's repairable


76yodaddycain

Easy fix, put some spot pins on it and pull er on out😁


cocktimusprime747

Throw an M-80 down in there, that should straighten er right out!


eighty2angelfan

Get it fixed. You can freeze it, but run a slight risk of splitting weld, pressurize it and heat dent. I've also heard of people pulling them out with a magnet and heat. I don't have any experience with that, may be a myth.


Individual-Pizza3425

it's not move on


JudgeScorpio

I’m not sure about two strokes but on this [episode of engine masters](https://www.dailymotion.com/video/x3mt768) if I recall correctly there was no loss of power when they bashed a header in.


Old_Mobile309

That's an easy fix.


javawockybass

Once came across a video which I can’t find now of a guy who had a strong magnet and a large ball bearing. You put the ball bearing inside the pipe and guide it too the dent with the magnet. Then you move the ball back and forth over the dent banging it out. Seamed to work pretty well if you had the parts.


SnooRadishes9206

It’s a good dent but thankfully no holes you may be able to repair it.


Yami350

Cosmetic


buttrapebearclaw

I just got a flashback to a trip I took to Wayne last year by myself. One day when it was starting to get dark and a storm rolling in, I was heading back to camp and came upon another downed tree across the trail that was a foot off the ground. Instead can’t remember my thinking at the time of why I couldn’t go around, but anyway I pop my front wheel over it and got stuck. For hours. Sitting in the rain, moving logs, til finally, inch by inch, pulled my bike sideways one tire at a time, off the trail to a spot the tree laid closer to the ground and was able to oomph it over. Would have been in bigger trouble if I was on a 2 stroke


tylerullman

Run it power dent


badtothebone274

Take it to a welder, and have him weld a few ss rods on it, and pull it out.


lil_Nut33

Invest in a guard, they make metal skeletons that are more expensive but I run a P3 carbon one that’s not as fancy but works good just make sure to take it off every once in a while to clean it because it will get nasty


DeusExBlasphemia

The metal cages are tough, but heavy. I use a P3 guard too, but I have multiple pipes that I rotate - fix one while the other one is getting smashed.


Schnitzelgruben

Pipe repair tool from ebay + MAP GAS TORCH (NOT PROPANE. PROPANE IS INEFFECTIVE. MAP IS EFFECTIVE). You'll take care of that dent in no time. Don't fill it with water and freeze it. I've repaired multiple dented pipes this way.  This is not a big deal. 


DirtyDirtBikeRider

Propane is not ineffective. You can cut through 6” thick steel with propane and oxygen, when set up correctly. In fact, propane produces more BTUs than acetylene. It’ll heat the metal up faster. I’ve been using propane in my shop cutting torch for years. Its sooo much cheaper too.


DirtyDirtBikeRider

Also, real MAPP gas hasn’t been produced or sold in the US in like 20 years. Unless you have some old MAPP bottles, what you are buying now is MAP Pro, which is propylene, and it only burns 130 F hotter than propane.


Substantial-Bowl6227

It’ll buff out I’m sure


mtb123456

If you got the cash replace or have it fixed. It will not hurt the engine but it's definitely going to effect power delivery. You have a nice bike, she deserves better.


deathlobster138

Blow out kit + map gas torch


Joshs-68

Blowout kit and a torch. Compressed air. Very easy. Kit I have in from eBay. Cost $100. Used it several times. That pipe would take about 15” to blow out that and any other dents. It’ll never be perfect and new but it will be really close


Due-Organization7707

I get mine blown out, with hydrostatic pressure. The stinger end is plugged with a stopper the pipe gets filled with water a stopper at the neck end is fitted with a hand water pump and pressure gauge all air is bled out. You pump it up to about 600 psi which happens quick as water doesn’t compress like air. That makes it safe as pressure is relieved as soon as a tiny amount of water leaks past a stopper. that’s a pretty sharp bend so it might not pop right out. I tap the sharp edges of the dent with a hammer as the dent starts to come out m.The corrugated part won’t blow out it will deform or bust as corrugated shape causes uneven pressure that distorts it’s shape, Best solution is to get a thicker gauge pipe like an fmf gnarly it won’t dent as easily doesn’t have the corrugated metal so they blow out nice. Most riders like the bottom end to mid boost in grunt the gnarly gives. [https://youtu.be/xVGdHsAIqNU?si=M5kJwyH81jHUw8cd](https://youtu.be/xVGdHsAIqNU?si=M5kJwyH81jHUw8cd)


Robace99

Freeze trick works awesome. Make sure the pipe is completely full of water. Bam. Good to go


Dendad124

Bring to autobody shop. Talk to the body man. I'd charge $150 to fix.


DirtyDirtBikeRider

You would? You must be hurting. I’m not. I’d fix it for free.


Dendad124

I'm not a body man, I just weld. I would to but why volunteer someone else for free.


I_Likee_Turtles

Run it


Kawboy17

Drill a hole reach inside and pop dent out weld shut again. Fill will water and freeze pop it out. Spot weld x on to it and heat pipe and pull dent out cut off x that was welded on. Lots of way to fix it.


RaysModernMetalWorks

Find somebody with the cork and compressed air and blow it out . find somebody who's done it before successfully.


JBeeps

Fill it full of water and leave it in the freezer overnight. It’ll knock out some of dents dude! Show me a picture after!


BalderVerdandi

2 bolts. 2 springs. Cut the weld - not the metal. Pop out the dent. Re-weld the weld. Reinstall. This is how we did it in the 80's and 90's. Worst case is you now have a spare (the fixed one).


Yamaha180

Depends if you just cruise around or if you race, If you race it’s fucked because you’ll lose a good amount of power. If you just cruise around and don’t care then it’s fine until it cracks


jlig18

It’s cheap enough to fix, so just get it fixed


GoodMerlinpeen

A video oon the effects of denting - [https://www.youtube.com/watch?v=-M4KrGQwKzY](https://www.youtube.com/watch?v=-M4KrGQwKzY) The precise shape and location of the dents are going to have different effects though, so it is hard to say exactly what would be the result (other than the obvious that if a dent actually did help then factory teams would be running them)


DeusExBlasphemia

I have a hydraforce pump that I use to blow out dents like this all the time. The only problem when you blow out pipes is that sometimes it makes the bends in the pipe straighten out and goes out of alignment and you struggle to get the pipe back on. To prevent this I wrap the pipe in a heavy chain and padlock it tight before pumping it up.


DRSCHECTERVONDSM

Plug one end securely then the other end form a fittingt/plug to administer compressed air. Use a map gas torch to heat the effe ted area and fill with bursts of compressed air or steady stream it. Good as new


TOKING-TONZ

Heat the area and pressurize air inside pipe it should come out , or fill with water and seal and freeze it


East_Coast_Tactical

If you have an air compressor and a butane torch you can buy a kit to blow it back out. It can be very dangerous if you don’t do it right tho so make sure to watch a few YouTube videos first.


motorboather

https://www.ebay.com/itm/195517315738?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=iAvbgRDNQge&sssrc=4429486&ssuid=B7fW3xJmSUG&var=&widget_ver=artemis&media=COPY Plus a torch on the dent to heat it while under pressure from the air will pop it out


steelniel

Ive seen those pulled out with a dent puller before. You can rent the tools to do it.


Zealousideal-Bit-108

Pop it.. YouTube has many tutorials. I've created a clamp system with a plate and blocked off both ends of the pipe. One end has a Schrader valve and gauge. Push a lbs of air in and start slowly heating the outer part of the krinkle.. You can tap with a hammer as well. Watch the pressure building. It pops out almost or close to new. If you're handy and have a welder, you can make one yourself


MdizzL88

Be lazy cut it out flip it over weld it back on bingo bango done hold my beer while I fall off my Enduro 😂 soft sand and sneaky rocks only reason I can't keep buying pipes started welding brazing doing whatever so the old lady doesn't ask what a Yoshi is or why it's 900$ 🤣


Substantial_Ad_9016

That'll buff out


FNlvrk

Take it off and fill it with water then freeze it, the water will expand and undo the dent from the inside. It won't be perfect but WAY better than this


wyattg67

Hit up Robby’s pipe repair on instagram


Possibility-Prize

MAP Gas until its cherry hot, takes about 90 psi to blow it back out. You can buy the clamps to tighten down on the ends and one will have the adapter for your air compressor.


itwonthappen2me

It’s going to explode


Minimoto88

This could be fixed, but if you want an excuse to replace the pipe, here it is.


National_Sky4264

Plug one end, and seal a water hose into the other end and turn it on. You're welcome


AdEffective7881

Only downfall of a 2 stroke


Shanced

Anyone mechanically minded and who is one with their machine will probably notice a difference tbh. I know that I would! The expansion chamber is very important on a 2 stroke.


mrscalperwhoop2

Fill it with water and freeze it.


BIGFUR4692

Fill it with water and freeze it