CDH-110 making no power

[glebati]

I have a CDH-110 engine from aliexpress. I bought it right before I came across the video by LA hover bikes about the engine but it was too late to return so i had to work with what i had.
So since in the video he told to watch out for metal shavings in the cylinder that might make the engine seize, I had to open it up and yes there were metal shavings inside. So i assumed the rest of the video was correct as well (everything he talked about in his engine was also present in mine) and did everything he told to do(expanded ports, polish head and block and soda can gasket) except adding a new carburetor and exhaust because I cant afford :c
I tested compression and it came out to be 140 PSI (I pedaled the bike with the compression test kit, and then let off the clutch while wide open throttle)
The muffler interfered with the pedals so I cut it off for the initial testing done in a park, where the engine seemed to make a lot of power (maybe because this is my first time on any motorized 2 wheel vehicle since im 15)
Then I welded the muffler back on at an angle so it fits and I can ride it in my neighborhood and the engine never made good power ever again, testing the compression again came out to be 140 PSI just as it was before

Some info on how it runs:
It starts with the choke slightly closed, but then runs and idles with it wide open
Clutch is working properly, I put extra grease in the bucking bar thing just in case.
Once I went wide open throttle uphill after installing the muffler and it started making a ringing sound but then stopped when I tightened all the nuts
Before I welded on the muffler it was powerful enough to literally throw me off because I wasnt ready for how strong it was, I made sure not to go wide open throttle but it still accelerated like crazy, now it barely goes running speed

Anyway could you please tell me any ideas they have on why this happened and how to fix this because I really doubt that just putting on a muffler would make such a drastic change.

 

[GW's Motorized]

If the muffler on that is a regular 66/80 muffler then it will be restrictive. Try pulling the cap off the muffler and see if it gets more power.

 

[Nickt919]

You mention the engine ran well prior to working on the muffler.

Then the engine did not run well after working on the muffler.

I would have to go back to pre-muffler work for a test.
If that’s not possible with the worked on muffler then you would have to try a new, same style muffler to make the comparison.

This would tell you IF it is in fact the modified muffler causing your problems.
Or.. any other new problem coincides with the muffler change.
In all likelihood the modified muffler is the culprit. You may have diagnosed the problem without realizing it.
Any air restriction or change, whether intake or exhaust, can affect an engines performance.

Changing the way a muffler lets air flow, more OR less air, will change engine performance…good or bad.

 

[glebati]

If the muffler on that is a regular 66/80 muffler then it will be restrictive. Try pulling the cap off the muffler and see if it gets more power.

I took off the muffler today, and it seemed to get more power, maybe the muffler was just not very good. Do you know any muffler that would not reduce power so much, because I need one, or else my neighbors will report me.

 

[GW's Motorized]

I took off the muffler today, and it seemed to get more power, maybe the muffler was just not very good. Do you know any muffler that would not reduce power so much, because I need one, or else my neighbors will report me.

Phantom Style Performance 2-Stroke Exhaust Muffler For Zeda Bicycle Engines

Now available, the all new Phantom 85 replica performance exhaust pipe made for Zeda 80 cc & 100cc motorized bicycle engine kits, features sound insulation.

www.bicycle-engines.com

 

[Chainlube]

I took off the muffler today, and it seemed to get more power, maybe the muffler was just not very good. Do you know any muffler that would not reduce power so much, because I need one, or else my neighbors will report me.

You can bend a stock one in a bench vise, so there is that option.

If you exhaust stud spacing is 40mm then this might be for you, remember you can always put a muffler on the end.

Amazon.ca

 

[robe]

I have a MZ65 clone on mine and put the stock exhaust on the end. It wouldn't start so I took the cap off and sure enough it ran great but was super loud. After the initial start I put the cap back on and it ran but killed the power really bad.

So cut the body of the pipe about an inch from the front end cap and pulled the guts out, I removed the baffles and the narrow pipe completely, drilling a 3/4 inch hole in the end cap. Next I drilled several more holes in the inner pipe, wrapped it loosely with expanded metal screen, then wrapped the whole thing with fibre glass cloth.

I used a strip of thin sheet metal and 2 hose clamps to hold it together, then stuffed the remain cavity with fibre glass matt, put the end cap on with it's bolt to hold the show together.

A lot of fooling around but it works really good, no where near as quiet as stock but doesn't kill the power and is a low budget mod.

I'm going to try to tighten the expanded metal to see if I can make it just a little quieter. I am going to go on a campaign to see just how much I can quiet the thing down. I got some header wrap, a piece of 1/8 cork for inside the clutch cover and my reworked muffler.

 

[speedybroc]

I have a CDH-110 engine from aliexpress. I bought it right before I came across the video by LA hover bikes about the engine but it was too late to return so i had to work with what i had.
So since in the video he told to watch out for metal shavings in the cylinder that might make the engine seize, I had to open it up and yes there were metal shavings inside. So i assumed the rest of the video was correct as well (everything he talked about in his engine was also present in mine) and did everything he told to do(expanded ports, polish head and block and soda can gasket) except adding a new carburetor and exhaust because I cant afford :c
I tested compression and it came out to be 140 PSI (I pedaled the bike with the compression test kit, and then let off the clutch while wide open throttle)
The muffler interfered with the pedals so I cut it off for the initial testing done in a park, where the engine seemed to make a lot of power (maybe because this is my first time on any motorized 2 wheel vehicle since im 15)
Then I welded the muffler back on at an angle so it fits and I can ride it in my neighborhood and the engine never made good power ever again, testing the compression again came out to be 140 PSI just as it was before

Some info on how it runs:
It starts with the choke slightly closed, but then runs and idles with it wide open
Clutch is working properly, I put extra grease in the bucking bar thing just in case.
Once I went wide open throttle uphill after installing the muffler and it started making a ringing sound but then stopped when I tightened all the nuts
Before I welded on the muffler it was powerful enough to literally throw me off because I wasnt ready for how strong it was, I made sure not to go wide open throttle but it still accelerated like crazy, now it barely goes running speed

Anyway could you please tell me any ideas they have on why this happened and how to fix this because I really doubt that just putting on a muffler would make such a drastic change.

Move your needle clip in your carb down to make it richer so it runs with no choke. If u have choke on and go wot or any throttle it will be a lean bog worsed with letting the choke off because it's way too damn lean given u only changed your exhaust and the extreme power u said it had with the exhaust cut too lean witch is a condition of the motor to cause it to seize or blow up or both.

 

[speedybroc]

Move your needle clip in your carb down to make it richer so it runs with no choke. If u have choke on and go wot or any throttle it will be a lean bog worsed with letting the choke off because it's way too damn lean given u only changed your exhaust and the extreme power u said it had with the exhaust cut too lean witch is a condition of the motor to cause it to seize or blow up or both.

Did u break the moter in first too ? Could be the problem if it's already broken in use 20.1 for hard riding I suggest a castor based or semi castor 2 stroke racing oil especially if u run a 44 t fix the carb and add a 28 t sprocket if ur under 170 lbs if your ovrr don't go lower then a 36 t with a almost stock motor I get to just about 90 kph with the 28 tooth .

 

[DAMIEN1307]

Did u break the moter in first too ? Could be the problem if it's already broken in use 20.1 for hard riding I suggest a castor based or semi castor 2 stroke racing oil especially if u run a 44 t fix the carb and add a 28 t sprocket if ur under 170 lbs if your ovrr don't go lower then a 36 t with a almost stock motor I get to just about 90 kph with the 28 tooth .

None of these things mentioned above have anything to do with rectifying his sudden loss of power.

The muffler interfered with the pedals so I cut it off for the initial testing done in a park, where the engine seemed to make a lot of power (maybe because this is my first time on any motorized 2 wheel vehicle since im 15)
Then I welded the muffler back on at an angle so it fits and I can ride it in my neighborhood and the engine never made good power ever again,

His power loss happened only after futzing around with the exhaust as you can see by reading this quote from him.