Random stalling issue

[Rusty_Nail]

So the last few times I've taken my bike out for a spin whenever I pull in the clutch, it will randomly stall. But it will start right back up. Sometimes it does it sometimes it won't. My guess is a carburator issue. It has the carburator with the auto choke on it and whatever stock jet it comes with. I pulled the spark plug out when I got back home while the engine was still hot and its showing a light tan brown color which from what I understand means the engine is running good. Any other suggestions on what could be causing it?

 

[Venice Motor Bikes]

Years ago, I remember a couple of bikes had a problem with shutting off when the clutch was pulled... It had something to do with the wires for the CDI being zip-tied too tight to the frame near the engine... It made zero sense, but after loosening the ties & double checking the connections, the problem went away.

 

[Rusty_Nail]

I do have all my wiring connections wrapped in electrical tape, but I'll check my wiring connections to see if it helps. I did recently get a new carb for my bike. Took it out for a quick spin today for the first time with the new carb on it. Seems to run REALLY good. Took it on like a 30 minute ride and so far it didn't shut off once on me when I pulled in the clutch. It looks to be a clone of the Speed carb. Seems to run MUCH better with it. Took the plug out to check it after my ride while engine was still hot and its a brownish color so engine seems to be running really good with the new carb. Only thing I haven't tested on the carb is if the jets can be swapped. I hope so. Clip on the needle is in the middle mark. Seems to have a LOT better torque vs the carb with the auto choke on it. This is the link to the carb I bought: https://www.amazon.com/dp/B0D56L37VS?ref=ppx_yo2ov_dt_b_fed_asin_title

 

[lumpenbike]

I'm glad the issue got fixed with the new carburetor. Still, it's interesting to know what was happening before. I had a similar problem with one of my engines. I would give it full throttle, and the moment I let off, the engine would bog down.

The difference was that in my case, the engine was connected to the rear wheel via a freewheel, meaning the rear wheel couldn't drive the engine itself. In your case, there's most likely a direct connection between the engine and the rear wheel. This means every time you let off the throttle, your engine was actually dying, but it kept spinning because it was being driven by the rear wheel. However, when you pulled the clutch, you disconnected it and saw how the engine actually bogged down after full throttle.

The problem was most likely with the mixture at idle or 1/8 throttle. When you swapped the carburetor for a new one, the low-throttle mixture got sorted out, and now it doesn't bog down after full throttle anymore.