CDHPOWER Flex Fit Poo Poo 

The torque bites in just a little harder once it gets rolling, eh? Mounting it the way you did is probably better for use on trails anyway, less likely to be hit by a stray twig or stone. For road use I rather liked having it mounted from a spare chain tensioner, that tensioner being upside down with a bolt through where the idler wheel would be so that the chamber and silencer were sat below the left chainstay. Definitely not the ultimate all-round pipe and the elitists will probably tell you countless things are wrong with it, but for the price it can be found at it's certainly not terrible - besides, throwing stacks of cash at these bikes almost seems to defy the object, one of their main appeals is their relatively low cost and simplicity; cobble it together and go, then mess with it, break it at least once, fix it and overall have fun without the need to sell a kidney.

I love that you test your builds and mods out on trails instead of like most guys who ride in parking lots or perfectly paved roads.

I ride alot at night. But like I mentioned before. The officer that is always on duty at night. Him and I was the only one that was out on the highway a couple of nights ago. One officer that had stopped me several months ago said my lights have to be hard mounted and shine 500 feet. So I went and bought 2 night lights that shine 762 feet. Haven't been stopped by him since. I'm grateful to have about five miles of highway I can ride and perty much flat. Have a great day. I'm getting ready to go ride my bikes. Sounds like definitely a missfire. Please keep the great videos coming.

"Grabbing more power" is called the power band" THAT'S the HAPPY SPOT,

I put one of these on my trike a while back and it really improved the motor. More torque in lower ranges, steadier run, easier to start, I have a larger bore motor and it really lets the engine shine. Since then I've added an exhaust tip that gives it a deeper sound

I have one of those on a 79cc 4 stroke. Didn't do anything for performance. But omg made it sound so much better (much deeper tone) and a lot quieter. Also no more backfiring. I also put an exhaust wrap that made it even quieter.

I’m usually not one to leave comments but I have to say that your builds are amazing. I can only pray that my build could withstand half the punishment that you put yours through. Great work man.

I installed this exhaust pipe for my Azrael today. It has a beautiful deep sound, I love it. And yes, it is loud. And I love it.

HOW AMAZING YOU GOT TO RIDE THAT BICYCLE IN THE FOREST WITH ABSOLUTELY NO DIRTBIKE SUSPENSION AND DIDNT END UP BREAKING THAT BICYCLE FRAME. THE OTHER THING IT'S AMAZING HOW THE ENGINE DIDN'T COME LOOSE OR THE CHAIN TENSIONER DIDN'T FLY OFF CAUSE THAT'S WHAT NORMALLY HAPPENS TO THEM CHEAP CHAIN TENSIONER ON REGULAR ROADS. GOOD JOB HANDLING THAT BIKE IN THAT DIRT.

My YD100 came with two base gaskets from the factory and it remains that way to this day, 7 months later. And mine too can be a little b. to get started. It’s been that way from day one. I also hate the “ lurching “ it does at low speeds! Very choppy and jerky feeling, although it is better since I modified the exhaust by just removing the entire baffle, end cap and all. Also really boosted the torque which was already above average and now is almost scary lol. Also put a hp carburetor on mine which has aided performance and helped kind of smooth it out as well as just increased overall responsiveness from the engine.

I was having the backfiring or four stroking at full throttle on my 2-stroke. What I found was that the carburetor float needs to be level to work right looking at your bike it looks like your carburetor is jacked up like mine was to where the floats not working right try leveling your carburetor by tipping the motor back some. See if that helps out but I had the same problem with it misfiring at Full Throttle or high RPMs. Good luck and as always enjoy your videos. Let me know how it works out.

WWOW!!.. Love it... and nice setup overall.....These motors and all accessories are the meaning of affordable fun,,, well, somewhat affordable.

I have this same motor that I'm installing tomorrow. Been watching your videos to prepare. Thank you bro. Love all your videos, bikes n guns 4 life haha

it sounds like its running lean, make sure you dont have any vacuum leaks, check spark plug every so often to see how it looks, it its white or grey its running lean or if its black its running very rich. a tanish brown color on the end of the plug is desired. i have a chart of how to read sparks plugs,i can send it to you on facebook if wanted

Thanks for this exhaust review.. I always worry about buying these on BikeBerry, SickBikeParts, and Amazon because people complain about these being expensive and also having a tendency to have low quality welds, not fit at all, or have any consistency in manufacturing.. I gotta say, out of all the aftermarket exhausts, even the ones that have the expansion and silencer at the end, nothing is ever quieter and more reliable out-of-the-box than the stock muffler.. I'd really consider purchasing a 40$-70$ exhaust if there were some manufacturer with decent QC that also makes silenced exhaust pipes with everything reliably welded from the get-go..

I've gotta say, the coolest part about this muffler is how the power kicks in when you start going. It starts off slow, but then speeds up dramatically as you go.

Thanks man I was pondering about one. And it sounds pretty close to mine.

I race 250 and 500 cc dirtbikes and You can def. Hear. It wants to come on the pipe at higher rpm. Because of price I'm gonna get one just to have for a spare. Great video as always

Wow that pipe makes a really unique noise when paired with that big bore 50mm motor

I'M GLAD you mentioned starting that was very hard i'll think twice about getting a pk80

But all "tuning" the pipe means is just calculating the volume of the expansion chamber and see how far it should be from the engine with your engine size. Seems like most straight expansion chamber for these bike kits are much closer to the engine, so maybe shorter flex pipe would give you more power?

That trail is nice and it looks like your going faster than 25 ish? Where did you get that flex hose exhaust pipe? I just had to use map pro gas to heat and bend my banana expansion chamber exhaust pipe to line up which I procrastinated forever but it was actually pretty easy after it got red. It was too loud / popping, sound wise and wouldn’t stay running even though I adjusted the idle screw on my 49 cc. It actually was running slower after I got it on so I figured it needed some back pressure. I ended up map gassing the factory exhaust straight at the pipe and using a grinder to cut about 4”s off the muffler with the cap off. Then I jb welded the cap back on with a double female / bigger pipe connecting it to my new exhaust. Now it’s faster. I drilled 2 holes in the cap to give it more output. Any ideas on what I can do to maximize performance between the carburetor pin setting and the idle? You said you lowered the pin setting for more reliably so if you raise it will that make it run hotter but faster?

I took the end peice off my stock exhaust and it actually lost a little power. Oh yeah 80 cc. 44 tooth sprocket. Put it back on. And had more power back. Just thought I'd try it. Was definitely louder. So in my neighborhood it's not worth pissing off my neighbors. But it was fun trying it

Pipe should point down to avoid oil buildup

I have this exhaust. It’s a good pipe for High end power but low end is Garbo

I enjoyed the popping of having the end cap off. But like you said. Not worth pissing off the neighbors.

I have this pipe from bicycle-engines. It makes a difference running it up vs straight or down. For me I like it straight down the side with a slight angle down. Keeps oil buildup away. I bet you have a puddle of oil in the line? For me on a Zeda 100 max I immediately noticed a large difference compared to stock exhaust. A ton more low/ mid torque. Also quite a bit snappier. I happen to like the sound difference too. I think it’s a great upgrade. I didn’t need jb weld though lol. Do you know if all the flex pipes sold are the same brand? Or are they just similar in looks. I’ve noticed some come in different colors as well. Maybe the internals are slightly different depending on who you buy from? I know this is an older video but I still watch them all. I should probably sub for as many times as I watch your videos 😂 I’m going to do that now. Hope to see more videos coming out

The flex part of the exhaust looks like a steel braided hose. What is on the inside? Rubber? If it is rubber, it will crack due to heat. I think you are getting improved lower end power due to the length of the flex part of the exhaust. The tuned exhaust on a 2 stroke is like a trombone. If the trombone slide is moved so the air path is longest, then it will create a low note. Conversely, if the slide is shortened, then it will create a higher note. For a 2 stroke engine, if it is a long distance from the cylinder to the expansion chamber, then it tends to create better back pressure in the lower end which results in better low end power. If the expansion chamber is close to the cylinder, then top end power will improve. If you look at the pictures of an 80cc 2 stroke dirt bike versus a 500cc, you can see how short the exhaust is on the 80cc and how long it is on the 500 cc.

i had misfire issues and mitigated it substantially by using 87 octane instead of a higher octance fuel (first gallon was 93 accidental) for easier combustion but if your issue is knock and not misfire this could be detrimental to your motor as you likely know

🔥🔥🔥🔥🔥🔥This is the coolest video ever

for u guys that want to buy an exhaust like that u should defenetly buy one, at high and low rpm they gain a lott of power and not from nowhere it's just their happy spot where I I usually choose for, and nope I already took my 2 stroke into some really high rpm and I got 80 kmh and I checked my piston it was all fine and perfect just need some full synthetic oil.

The flex pipes that I've used way back in da day did not last. They either had like a rubber inside or thin metal so it would flex. In either case they don't last. Once it wears away inside that steel braided covering does not hold in the exhaust. The steel braid is to protect the metal or rubber on the inside. Even on cars I've seen the flex pipes blow out after a while. I guess if you don't mind getting a flex pipe every so often then it's cool. That power gain you feel is when the engine is coming into it's power band. That is what you want. It sounds like the bike is bogging to me until it hits it's power band or sweet spot. I bet if you lowered the gearing you would come into the power band sooner & it would have even a much easier time going through those trails. I don't think your that type of rider though. Most two stroke riders like an aggressive type of ride out of there bike or motorcycle. I don't know if you have done plug checks. That is the first thing I do to every two stroke I've had. Not sure if you know how to do that . I usually run it wide open at top speed, cut off the ignition while wide open, then pull in the clutch. Take out the plug & read it. This way you would not be guessing at what plug heat range to run & to know to go richer or leaner on your fuel mix & carb adjustment. Myself I like a snappy two stroke rev. Ride on , like your video's.

Outstanding scenary

Ahh the wonderful 2 stroke power band😌

My friend just got the same one lol he said it gives him more power

I think that the knocking you're talking about is just the expansion chamber doing its thing

Hey brother something that helps those carbs a lot is to put a good air filter on it and put a smaller main jet go to a 65-68 anywhere in that area it will run sooo much better if you think it pulls now brother you in for a treat ...and it's very cheap a jet pack is less than 10 bucks ...the Jets are 5mm threads ...when you were at full throttle and it went clean and started pulling it was the chamber finally working ...lean the jet down and it will be like that all time and it's even better on the engine more efficient...

Hello man, so you are riding on trails which i am riding on, but for less hassle im going to down grade to a 50cc 2 stroke engine. I have front shocks but man my bike shakes the crap out of me over rocks and such, the spring shaft seat a huge relief for this?

My yd100 is currently only running on 1 ring on the piston cause it blew up but I got another motor kit on the way

I JUST CUT THE TOP OFF MY YD100 AND DRILLED OUT THE HOLES ON A HIGH COMP HEAD AND GOT IT TO FIT ITS A BEAST YOU SHOULD TRY IT

hell yeah way to ride ! waaaaahooo let er rip ! what a BLAST

I wonder where I could buy just the flexible portion, to bring my own muffler?

I know that is not for this video but i learned new awasome thing... You can take of this 2 storke 80cc bike by playing little bit with the clutch lever... I was stuck on the hill and I wanted to go up and I tried to take of withnout pedaling so i Give it a gas and then slowly really carefully started to lowering clutch lever and at one point the clutch is half engaged and half way not it a half centimeter before the clutch lever is full in... I recomend you give it a try its kinda fun if you learn it... But you need a lot of trys... One mistake or realising to fast and it will die on you so you need to start it again... Sorry for my English but I hope you get what i mean... And U dont need centrifugal clutch to be able to do it... I have stock one and it work like a charm... Just need a lot of practice to get a grip to it

My pipe is tuned for torque. 35inches from flange to end of chamber . power up high is a short pipe. lower the band add an inch to the header. 4 stroking at full throttle is rich or long pipe How long your pipe? flange to end of chamber

What's up hover fellow Louisiana boy (Bossier City)here just finished building and breaking in a hyper cruiser with zeda triple 40 ported and skirted ,f2 exhaust it's so much fun I've hit 47 mph on it it's a blast. Just wonder what Jets you run when you start at 40 : 1?

You need to build a like a 15×20 shed to work on the bikes in

I put octane boost in my bike and stoped pinging mostly. Only pinged when cold but now boggs alittle at top end i may try adding exzhast flow seeing if that helps in little steps. I also have a car spark plug wire that seemed to make it fire better aswell. Sorry have no clue what motor is its third hand and sat in a shed for cupple years. Goes good for the most part shaky rims tho hahaha

It’s interesting just bought my self a cheaper option of the poopoo pipe off amazon for about 50 w/shipping and I notice that my expansion chamber and silencer are a bit smaller. Just for anyone to reference, or even a heads up, and might want to pay a little more for the extra size of expansion and silencer. Trying my hardest at the moment to get over 30mph

it sounds like its 4 stroking but i could be wrong, could be a too rich mixture anyways by now im sure youve figured it out

i've used hose clamps to mount both of my bendy pipes. like you said there's really no better way to do it.

The factory exhaust was cutting speed. Just removing the screw changes to speed dramatically

My chinadoll was making that exact same sound during break in near full throttle. Have you found out what it was?

also if you try to modified red plastic on your carb find a way make it breath better but not loose the filter that may help as well there also a bt 100 engine and a bullet motor with eletric starter

For the overheating, simple bolt on or clamp on aluminum extension plates onto the head, extending the fins not much is needed depending on temps, high temp JB Weld works as well, Other option is a simple plate with a few 1/4 holes for flow behind the motor to stall the cooler air at the motor for longer, ( I use this when temps get in the 80's ) I have simple hose clamps around the top cross bar down to a 4" X 8" wide plate of aluminum, a series of holes I experimented drilled for flow ( it's needed, can't stall all the air it has opposite effect😨)

Grate video keep up the good work. Keep making them.

Awesome dude

A colder heat range on a plug will not make the engine run cooler it will just transfer heat faster from the tip of the plug!

Yeah I did the whole pedal start shit for the first two years of build me a thing and then I called it quits when I found out there was a lousy $10 pool start option that you can add to it now I just pull Starley and it’s so much better and I just wish I could quiet it down somewhere people didn’t hear that much

Add extra oil to the cylinder when new so it has oil in bottom and it stays cool

hi,Ise you have the big sproket ,what chain number of chain are you using?i just got that mufler!!!

how did you tighten the ngk sparplug? it has a bigger diameter and the tools dont fit while putting it in the yd100

Good video it looks cool and sounds better

Pulls more power b4 it selfdestructs lmao😅 sounded really smooth at high rpm tho

That sound is NOT knocking, it's in fact quite the opposite - it's '4 stroking' caused by an overly rich condition. I encountered the exact same issue when I too fitted this exhaust to my setup. I fixed it by going from the stock 0.70mm jet down to a 0.65mm.

Hey LA hover, was wondering what app you use to check your top speed?

In the old days, motorbikes were run on methyl and Castor oil. But I saw a guy running a two stroke on pure olive oil

What I'd give to have trails like that in central Florida.

It sounded better at the higher rpm too! I know you don't like to hold it wide open but that engine seemed to have liked it! What I want to know is does this engine offer enough benefit to justify its added cost over the 80 cc engines?

I like your voice it's very calming to me for some reason

What are some ways you can prepare a band new engine before installing it completely ?

What area do u live in? That would b so fun to ride thru woods like that

the long header tube brings the low end torque

What app do you use for your speedometer on your phone?

Whaaa? Doud,I totally am pulling 40mph with a 52.tooth n 4mm of port exhst n intke on wooded trails with my YD the potential with these heads is up there my guy!

Did the sound of your engine go away? Because I did not change anything on my bike and it was doing that but when I look at the fuel line I saw that it was squeezed.

where do i buy an equal? and how much is it?

@LA Hover lol hey any Bigfoots chuck rocks at u yet?

I tested the compression on these motor and they should be about 115psi

Wonder how heavy is that when used manual pedalling?

What is the name of the Speedometer App you use?

What do you think the best bike is to motorize?

Where do you purchase flexible pipe at ?

if you don't mind my asking where did you purchase yours 100 cc from and how much? I'm sure you have said as much in videos but if so I missed it!

So are you going to be live tonight

You could have skipped a tooth or it might be off 180 degrees or detonating prematurely mine had a knock and wouldn’t idle well then I swapped frames changed the spark plug tightened the clutch and loosened my chain a little it runs super smooth not much for speed but definitely smoother

Can this climb an uphill that's around 20-25% gradient???

I’ve had to run 2 base gaskets and it does mess with time just a little bit my motor is extremely modified and it took a long time to get in the power band but since you ride trails you would benefit by putting the two base gaskets or you could raise the exhaust port and lower the intake port to get ride of the knocking sound. One question tho what size sprocket do you run for trail riding it looks like you have a lot of low end power

Check the distance between the piston and the top of the cylinder they might be hitting that thing should be pulling the front wheel up with a 56t

Does this exhaust work good as an expansion chamber... got one from my old bike but don't wanna use it if it's only gonna be a noise maker

So I just got my motor two days ago and my bike frame is to small, the carburetor fits but without the filter. Is there any way to get that bit of extra room?

Hey Can you do a video on getting the gas and air ratio right so that the bike stays going? I just built my YD100 and the clutch only fully engages when its pulled all the way down, and it is a really crappy halfway engaging clutch, when I lock it with the clutch lock. So I can't really have the bike stopped and going, it always has to be moving, at least so far. My climate is about 0 degrees celsius, just above freezing temperature, is it dangerous to go about with the stock jet? Have you got some recommendations for me for such cold climate?

Did that bike come from Walmart? If so i think I'll look at a few

Yeah that 'pinging' is from lousy gas. Seriously thinking about running Avgas in mine...no alcohol and MUCH higher octane...mad expensive though...

24 mph, i get 26 out my 66cc.? so annoying on the but hole when full throttle.

Good video

Although I am told that the four stroke bike motors are a lot quieter

AWESOME

Do you use liners holy shit I'd have five flat tires with in five feet of that

HARD TO TELL ON THESE MOTOR COULD BE THE SPARK PLUG SWITCH IT TO THE OLD ONE SEE IF ITS DIFFERENT ALSO ID GET SOME LUCAS CAR ADDITIVE AND ADD A FEW DROP ON THE WHOLE SEE IF IT STOPS IT CANT HURT IT JUST A DRIP ALSO IF IT IS A KCOCK MIGHT JUST GET YOU BY A LIL LONGER GOODLUCK

Your videos are getting so much better and is it much louder than the stock?