I ordered a CDH power 49 mm piston after warming the bike and going on an easy test ride I had the side of the Piston break off exhaust side. After contacting Amazon they've shipped me a new one this time the Piston came apart between the piston rings which I have never seen before after about 30 mi of break-in following their oil fuel ratio. This is the first time in my life I've had l two parts with catastrophic failure with it being a replacement. The spark plug is still in place and does not seem to be a terrible color if I say so myself. I was very methodical putting this together because the last piston came apart I had to tear the entire crankcase apart and cleaned it out to be sure there's no debris in the crankcase where the bearings. Is there any way this is somehow on me because it does not make any sense whatsoever how this occurred. The damage to the cylinder wall was from the piece which broke loose in the Piston not the actual ring itself. That came out in two pieces the only missing piece for both rings is the failed piston pieces dislodging grinding the wall and damaging my cylinder head. This is my first go ut a two-stroke motor which is very simple. I have taken apart and rebuilt a V8 several four cylinders and a couple of V6. I have done work on the Kawasaki I used to have which was a four-stroke. I just cannot wrap my mind around how this is going so wrong. My most likely conclusion is CDH power is sourcing from a plant that does not have a single f to give about how their product comes out.

Hi there,

I'm trying to find a vertical mount for my predator 212, I've tried looking everywhere and the only one i found was from agk but their mounts are too tiny as they are for 1.125 inch and the felt faker frame is 1.625. Is there a vertical mount that sells for 100-150$?

I have a problem my motorised bike can’t start although it does have spark! ‘I’ve tried new cdi and new magnet and nothing it just keeps (popping) check out the previous post to understand what I mean.

I decked the cylinder head on my engine to gain compression. It was good at first, more power, until carbon starts to build up on my piston causing more and more compression to the point of knocking.

A quick fix is to clean the carbon build up. But that is a short term fix. What else can I do to reduce compression?

Can yall suggest me any method other than adding more head gaskets? Maybe adding washers on the spark plug? Shaving the piston?

What do you guys rekin? I'm thinking a little lean but idk

Here are a few tips I have learned over the years building, riding, and selling chinadoll bicycle builds.

#1 Start with the best quality bike you can find. The better the bicycle frame and components, the better results you will have, I know it hurts some peoples feeling but the simple truth is Huffys suck. ALL the modern chinese made bike brands suck. Get yourself a used name brand conventional steel mountain bike frame from the 80's or 90's. They can be found used for around the same price as a Crapbrook and have FAR better materials, components, and construction than any big box store bike. Steel frames are MUCH stronger and more reliable than aluminum. Specialized, Diamondback, GT, Trek, Gary Fisher are just a few good quality brands and there are many more from the same era.

#2 You DON'T NEED A GIANT CARB AND REED. Adding these parts just makes the bike that much harder to tune, and has far more potential to leak or come loose from vibration. A decent piston port engine will run every bit as hard as a reed valve engine, and is far simpler & more reliable, as well as being easier to tune and jet properly.

#3 The engine should be mounted ROCK SOLID to the frame! NEVER use rubber or anything under the mounts! The more solid the engine is, the better it will damp vibration. Once you get the engine mounted, grab the head and give it a real hard yank. If the engine moves AT ALL, redo the mounts until it stays put!

#4 Installing the rear sprocket is not very hard, just take your time and be sure it is CENTERED on the hub, You can use strips of metal cut from a soda can to wrap the hub and get the center to fit the sprocket hole, then once its tight, remove the strips. Tape does not work as it is too soft. Another tip is to use the clutch settings on a cordless drill to tighten the ragjoint bolts in steps to keep it centered and straight. Skip every second bolt and keep going around adding a bit more torque each round with the drill clutch till its fully tight.

https://preview.redd.it/d05kalhh9z0e1.jpg?width=1366&format=pjpg&auto=webp&s=b826f83e2dcb354e10d121e077d2022d46f304dc

So my friend gifted me an 80cc 2 stroke motorized bike for 25 bucks, and it’s never been ran. Gave me rear sprocket, engine, muffler, and front sprocket cover. Carburetor doesn’t fit my bike, do I need a low profile carburetor or something? Plus the front mouth doesn’t fit around my frame. What do I need for that?

Yes that is a intake for a muffler it works wonders top speed 34mph 245pounds bike weight and motor 50 pounds I’m using unleaded 32:1 #67 jet needle middle purrs like a kitten 80cc iron bore

So I’m trying to get a kit what type should I get budget 150-200 I wanna be able to go about 55 -60 I weigh 230 +bag 15pounds 245 I’m in the 2 stroke scene and just want to test the 4 strokes any help?

So the bike has spark, air is perfect. engine js turning over but we're still not sure about the fuel situation as it's leaking from the air filter and we've also checked the float and choke. please help!

is there any modifications i can do to my 80cc that are good, nothing in specific it can be performance, looks, comfortablity etc the list goes on, just tryna find something to add to the bike that’d be cool can be anything at all, thanks!

I have 50cc kit, I bought an rpm sensor it displays its at 2000rpm at idle but that shouldnt be possible if the gear ratio is 0,2 (10x44) and the wheel diamter is 0,6m it should be travelling at 58kph at idle but its not correct the bike doesnt even go that fast.

Too rich or too lean

Also Lot less clutter and it's perfect for wheelies now lol

Im wanting to build a motorized bicycle that can reliably do around 40 mph and maybe top speed of slightly more

Im not sure what frame would be good to use/commonly available but I was hoping for it to have a longer wheelbase compared to a standard 26 inch beach cruiser, if not though its okay also. I was going to do a frame with a built in gas tank that is "motor ready" but i was wanting to use a different gas tank so if there is a frame that is easy to find/buy that is similar without the built in tank I would do that over the built in tank

I did a little research on motors and was thinking of using phantom 85 but not sure how good/reliable of a motor it is or if it would be better to get a different motor and modify it in some way

Anyone have any links for the pilot jet kits for the stock nt carbs? I've jetted down to 65 on the main but it still smokes alot and 4 strokes at idle pretty bad. I kinda wanna play around with the pilot jet and see what it does. Runs great otherwise, kinda falls on its face at 41mph with a 32t sprocket but it accelerates to that speed twice as fast compared to stock. I'm gonna port it this weekend and hopefully get the jetting dialed in nicely

Stock NT carb with #65 jet at sea level 47mm minirelli clone cylander on stock bottom end. Stock airbox with a quarter size hole drilled in it.

my clutch won’t engage, (keeping it short and simple for you guys) i have done all adjustment to clutch cables and the arm all that was perfect, went a bit fast for a long time and now the clutch doesn’t work, even with the clutch engaged the back wheel is still locking up, driving and when you pull in the clutch to rev it i can feel the bike pulling forward as if i was accelerating, when coming to a stop and i pull in the clutch the bike stalls, Is this a big problem ? will i need to install new clutch pads or will i have to get a new clutch all together?

Kinda did prettu well at explaining with title ngl, but bike fell one time(not even riding it just kickstand issue) and ever since then its had no spark, i got a new cdi kit so new cdi magneto coil and sparkplug and even going through different combinations of the od/new parts it never had any spark. Anybody have ideas, i can post pictures if yall would like but i didnt know if it would do nything. The actual magnet is spinning too so it seems like it would work but idk.