Can't get bike over 23MPH

[Chainlube]

Here's one of my bikes with a 48cc that runs 31-32 with the same gearing you have, we weight about the same too. I'm at about 900 ft above sea level.

Is that the same vendor as the other two? I like what you did with the stock muffler.

 

[DistantWolrld101]

Additives in ABS for use in 3D printing (generally to improve flow characteristics by lowering the glass transition temp (about 220degF), which is much lower than the melting point and would be reached in a friction drive application like this in no time) are different than those used in injection molding processes, which is how actual parts (not trinkets) are made, where they may be for impact resistance, rigidity, UV resistance, etc. Its actually an amorphous material and has no true melting point. It has a transition zone from solid to liquid thats quite wide and starts to get soft at very low temps relatively.

The stuff used in your 3D printer is not the same as what's typically found in manufactured products. Its generally a higher styrene content, hence why 3D printed ABS objects are rather weak in comparison regardless of layer adhesion properties. Even if its fully bonded and annealed. So don't get confused about your 3D printing material being anything like typical manufacturing industry plastics, as they are not.

True, ABS can be quite strong if done correctly, but it isnt a fantastic friction material. We aren't talking about "strength" here. We are talking about heat tolerance, and abrasion resistance which "friction" tends to induce.

A more appropriate chemical test would be acetone, which would show indication of dissolving immediately. No need to wait for gasoline to do its job, which is rather slow at dissolving ABS unless it has more styrene than typical, and these certainly would not even if they were ABS. At least I would hope not and they certainly don't seem to.

I suppose there could be some obscure ABS/solids composite that is used as a friction material, but I doubt it would be for an application thats subject to the type of conditions a clutch would put it through.

I am a manufacturing engineer of almost 30 years... I tend to know what materials are capable of.

Drop them in your clutch basket and give them a shot. It hardly matters what they are actually made of if they are doing their job as expected.

One thing thats immediately apparent is there is no wear in period with these as there is with the red, or the black/white ones where it gets better over a bit of riding as they bed in (if they ever really do at all). They are good right away with no perceivable change after riding a bit.

i don't have a trinket style 3d printer.

you make a Mold with 3d prints or CNC, fill it with what ever material you want and it injects it into a mold

 

[Greg58]

Is that the same vendor as the other two? I like what you did with the stock muffler.

That’s one from Amazon, it runs well with the small stinger on the 48cc.

 

[BrainPain]

I have not read all of the thread Bicycle digihud app is accurate I have a bicycle computer and the app on my cellphone there within 1-2 mph of each other.

 

[Emcee]

I have not read all of the thread Bicycle digihud app is accurate I have a bicycle computer and the app on my cellphone there within 1-2 mph of each other.

Tomorrow when I get my new carb I'm going to run 10, 15, 20 MPH. Record the RPMs, do a second test to get a avg and then compare it to the app. I only use Google maps because of it showing MPH, I honesty know where I'm going when I'm going. My JRL NT carb comes tomorrow. Unsure if their is a difference between the JRL and the stock NT but we will see.

A friend of mine gifted me some motorcycle rear saddle bags that go out my rear rack. Super stoked to be riding in more style now

 

[TheWizzerd]

Tomorrow when I get my new carb I'm going to run 10, 15, 20 MPH. Record the RPMs, do a second test to get a avg and then compare it to the app. I only use Google maps because of it showing MPH, I honesty know where I'm going when I'm going. My JRL NT carb comes tomorrow. Unsure if their is a difference between the JRL and the stock NT but we will see.

A friend of mine gifted me some motorcycle rear saddle bags that go out my rear rack. Super stoked to be riding in more style now

The JRL one is a BoFeng. Yes, its miles better than the typical NT carbs in every way. Other than jet selection being a bit more limited and not as available, but you may not need to re-jet. The stock jet in the BoFeng is a 70.


EDIT: The BoFeng has a much better needle profile than the NT, and an additional needle adjustment notch. Most often the stock 70 jet is fine for a wide range of engines/altitudes, and the needle adjustment is adequate.

Make sure it came with the o-ring for the intake mating surface. Sometimes they are missing. It is necessary to prevent an air leak.

 

[DAMIEN1307]

The JRL one is a BoFeng. Yes, its miles better than the typical NT carbs in every way. Other than jet selection being a bit more limited and not as available, but you may not need to re-jet. The stock jet in the BoFeng is a 70.

Even at my 4500 foot altitude, I have never had to re-jet my NTs or my JRL BoFengs that I now run...The Bofengs are much, much better crafted than the basic NT or even the ones they call a "speed" NT type carby.

 

[Emcee]

The JRL one is a BoFeng. Yes, its miles better than the typical NT carbs in every way. Other than jet selection being a bit more limited and not as available, but you may not need to re-jet. The stock jet in the BoFeng is a 70.

Isn't .70 also the same jet size in a stock NT?

 

[DAMIEN1307]

Isn't .70 also the same jet size in a stock NT?

Yes it is but the BoFeng and NT jets are NOT interchangeable since there is a physical size difference between them even though they are both #70 jets...The BoFeng also has the emulsion tube that improves carby performance that the NT does not have...When you get the new one, you will also notice the BoFeng is much better made than the NT with a more hefty design where the intake tube slides into the carby with a more heavy duty connector where you tighten it as well....NTs have been known to crack and break at that point when tightened, whereas the BoFeng is built for better tightening without cracking and breaking as easily.

Ps...BoFeng has much better, more consistant, smoother, and responsive throttle through all ranges, much better idle consistency and improves gas mileage.

 

[TheWizzerd]

Isn't .70 also the same jet size in a stock NT?

Yes, but its a different type of jet and incompatible. Otherwise its a quite different carb.

Its much better made, actually seals so you dont get air leaks, atomizes fuel better, tunes much easier due to all of that.

Throttle curve is much more linear and responsive, etc., etc., etc.

You will be happy you went with the BoFeng.

At any rate, do not go back to your old carb, or any other for that matter (unless you are getting in to really high performance stuff). The BoFeng is a great carb and will treat you well.

I like pumper carbs like used on chainsaws, weedwackers etc. due to their ease of mixture adjustment, BUT, the BoFeng runs so perfectly on these engines, and just works.... I have ditched the pumpers on a few builds for the Bofeng.