Major cold start issue on Bintelli 50cc

[radid]

2013 Bintelli Sprint, 1955 miles.

Hello fellow scooter riders, after about 45 minutes of being turned off (cooling off) my engine will not start unless I crank it with the electric starter for about 45 seconds straight (ouch) I had to go through this about 4 times to not be left stranded as life doesn't slow down because your scooter fails  , so I have found out that removing the choke and plugging the opening it leaves will make my problem begone and my scooter will start right up when dead cold so I must let the engine warm up for like 45 secs then open up the choke's opening(makes my engine inevitably stall), screw the choke back on, crank the engine and bam my scooter is running strong.

What should I do now.

already did valves and checked for vacuum leaks.

I tested the choke and the needle goes up and down about 3/8ths of an inch with temperature as intended, could it be that it's still not working as intended?

Could something in the choke area be plugged?

Is this simply a fuel/air mix issue?
since the choke appeared to be working correctly, I would think the additional air that will inevitable seep though the choke's opening as I start the scooter makes it not struggle to start. At the same time letting any significant amount of air through the choke's opening for even one second will stall the engine even after warm up.

My sparkplug shows an appropriate burn.

The road is unclear for me I don't want to buy a choke without needing it, the sparkplug burn is good and my scooter runs strong.
I don't wanna clean the carb if its not needed.

Any advice as to what troubleshooting I should perform is highly appreciated thank you once again for sharing your knowledge.

Engine Specifications



Engine Type: BN139QMB

Cooling System: Air Cooled

Bore X Stroke: 4 Stroke

Compression Ratio: 10.4 : 1

Horse Power: 2.4kw/8000r/min

Max Torque: 2.8N. m/6500r/min

Ignition Type: CDI

Starter System: Electric/Kick

Engine Oil: SJ10W-40

Transmission: CVT

Spark Plug: CR7HSA

Belt: Gates 669MM

[gsx600racer]

I would take the air box cover off, remove air filter and give it a shot of gas or starting fluid into the snorkel or take a rag and soak the corner in some gas and tuck it into the snorkel and try starting it. If it fires off immediately, then its safe to say you have a fuel delivery issue and chances are the carb will need to be removed and cleaned.

[radid]

I tried your suggestions neither worked I used the rag with gas and carb cleaner in that order in the air intake after removing the air filter and no fire I then just removed the choke and it started just fine then put it back on and the things runs with no issue

However my air filter was wet when I opened it after the bike being off for the whole night.

It was a greenish oilish substance I couldn't identify it, it was definitely aromatic but didn't smell like gasoline or oil.

[radid]

I also tried to tune the carb but my carb doesn't appear to have a screw instead it has a plastic plug with what looks like a half washer it was also sealed by a metal cap I took off with a chisel and a hammer so I didn't mess with it just capped off again.

It is a Deni Carb

[radid]

Lol so many bumps also where the mix screw usually goes its just sealed off with what looks like a metal cylinder in the screw hole

[radid]

My cold start issue has been solved for no apparent reason, everything is back to normal the only thing I can think did the trick was riding through about one gallon of gas with a high dose of B12 chemtool as everything else is the same as when the issue began.

I will be running fuel treatments for a while to see if I can get away without cleaning the carb ,


If it ain't broken...

[GrumpyUnk]

If the sponge that does the air filtering gets oiled or coated with liquid, it will not pass air as well as when dry. OTOH it may hold onto more dirt. I think an oiled filter will result in a slightly richer fuel:air mix than normal. If too rich, it may be hard to start. Removing the enricher may allow more air into the carb as you 'break' the fuel passage seal to atmosphere by removal. FWIW, as you have effectively done some cleaning by use of Chemtool. You may have a recurrence, and if you do, I would suggest cleaning the float bowl, and removal and cleaning of the pilot jet/emulsion tube, and the main jet & its emulsion tube. The pilot jet is so tiny that just about anything can plug it, causing hard starting and poor idle.
tom