Help on tao tao bike
 

I've got a 2017 tao tao hellcat 125cc bike,I'm trying to get it started but all its doing is cranking, I've replaced the spark plug and have charged the battery,still nothing.any advice on what I need to look into next. Not very familiar on this type of bike.Thanks all.

internal combustion engines require 3 things, fuel, spark, compression. You're missing one of them.

I'm pretty sure it's the compression, has fresh fuel and a new spark plug. What parts deals with the compression.

Is the fuel making it into the motor? Is the spark going across the new spark plug at the correct time? Did you check the valve lash?

Adjust the valve lash. You haven't given much background on the bike (e.g. new, used, estimated mileage/hours), but generally the valves are supposed to be adjusted approx. every 600-1000 miles (vertical thumpers, not sure on the horizontal engines, like what you own or what are found in pitbikes) or so. If your bike is new (e.g. new, never used) sometimes the valves come too tight from the factory and a bike won't start. Used bikes--the valves may have been set by the old owner, and possibly reset depending on mileage, and then you bought it running, but eventually, the valve lash will need adjusting.

There are several videos on valve lash adjustment for vertical thumpers, so I am guessing there must be several videos on the horizontal ones. Many members have Vaders, and I have not seen Hellcats lately, but surely there are plenty of threads to research on valves, and/or videos on YouTube. Check out Motocheez's videos on his Hellcat, but he did a complete engine upgrade by exchanging a ZS190 engine for the stock 125cc engine, but look around his channel.

What is the valve lash? It's used and been sitting for a while,it showed about 50 miles on it but I says 900 on the title.

Valve gap adjustment,easy to do. Will start better if it the problem.

Anyone ever heard of a startup procedure?

We are dealing with a guy that knows nothing about motorcycles or their engines and you have him dealing with valve lash and compression and crap with no real bearing on a bike with 50 miles, or even 900 miles, that is 6 years old! You guys are skipping steps 1,2,3 and going directly to step 13.

The last thing the previous rider should have done when he turned off the bike was close the fuel valve. So the first thing you check is the fuel petcock. You then turn on the ignition and then check the kill switch. Any of those things will cause a "crank, no start" situation.

The next thing you would suspect on a bike that is 6 years old and has 50 miles is a clogged carb.

No one said a thing about pulling the plug and checking for spark.

No one said check the air box for a rats nest, or the muffler for the same.

Like post #2 said; fuel, spark, air.

Compression and valves have to be way off for one of these little 125cc flat engines to not run. Bad fuel supply, no spark or clogged air flow will stop them dead immediately.

This times 1 Million. OP responds with "what parts deal with compression" and they want him to be messing around with ignition timing and valve clearances?!

Price, so as krat mentioned...check to make sure nothing small and furry made it's home inside the airbox or muffler. Make sure fuel is turned on and flowing.

Then maybe pull the spark plug and plug it back into the wire, hold the threads of the plug against the metal engine and crank it, see if it sparks (or sparks YOU lol).

I'm willing to bet dollars to donuts that the carburetor is clogged up from sitting. If so, go to Youtube and start watching carburetor cleaning and removal vids.

You're going to have to learn some stuff along the way here, but eventually, you should get it.

Five things required.
 

There are five things that are needed. fuel, spark, compression, oxygen (plugged air filter?), and all at the right time (I learned that the hard way when my 250cc BSA Trials bike distributer bounced up, its shaft turned 180 and dropped back down in place). It took me awhile to figure out why it would not run in light of the fact that it had fuel, spark, and compression (but not at the right time).