Four of my mini's are running these engines and I have never had a major problem with them.
You MUST run the engine for 30 minutes and drain the oil out to remove sand and milling flashing from the factory. This will greatly increase the life of the engine.
At this point of frustration, you have a wet spark plug. And it is a quality brand,not Chinese crap.
You report that you have a blue/white spark out of the engine and not yellow.
The engine was working before the mods.
This can be caused by several things with the Mikuni carb as posted.
After you get the carb back onto the engine, and you try to start it, spray some brake cleaner around the manifold and try to start it.
If it runs or was running on gasoline and the brake cleaner is sucked into the engine because of an "air" leak it will speed up.
Ran across this decal in my mini bike stuff.
Elaine and I went to the gathering and it was fun until the police showed up,twice! and tried to arrest a couple of riders for "Fleeing a police pursuit"
I think Gestapo issued some fines as well.
Even though Old Paul had permission for us to use...
If you bought the carb off of the internet it is possible going to the seller or to your home, the carb was "handled" while shipped with some gusto.
ie, it has been thrown around.
It would not take much to bend the float tab or crack a seal on one of the floats. I'd check this first. I've have...
Another test you can do to prove what is going on is:
As Ole has written, when the engine dies to check the fuel level on the carb bowel, pull the spark plug out of the engine. Is it wet or bone dry?
If wet your getting way TOO much fuel.
Pop-corn Phart dry, your starving for fuel.
In case you have not checked it, on many of the HF carbs just behind the fuel inlet fitting there is a screen. If this screen gets clogged ( very common) you will have very poor fuel flow and the engine may not start.
There is a Youtube Vid on how to clean this screen.
Manual lathe,no threading device. My plan was to buy a SS rod and hand thread it. Then the link to these axles was presented.
I still have no idea what the correct torque specifications are for this mini.
I'm hoping that the friction points will resist the torque trying to pull the axle forward.
If it does move again,I will torque to 100 foot pounds.*
I bought a spare axle just in case the first one fails.
*When I got a flat rear tire several years ago, I had to pull the rear tire/rim off of...
I just can't win for loosing....
The new axles showed up today from Go-Power Sports. Two things wrong right off the bat. 1. The axles are not 15MM. They are .004 too small in diameter and are loose in the bearings. The old axle is 14.94 and the new axles are 14.66. A loose fit in the bearings...
I disassembled all the drive parts to the rear wheel to get ready for the new axle which has been shipped. I noticed that the drive chain had been rubbing on the inside of the chain guard and I modified the plastic TAV cover and adjusted the chain guard up an inch to prevent this from happening...