Why can a small carburetor cause and engine to overheat?

Question edited for full 'year make model (what it is).
Question moved from motorcycles to make model category.
Please don't type in all CAPS, it is considered SHOUTING and is harder to read.

'clips' and 'turns' it took me a while to realise you were talking about the carburetor and you were playing with the mixture screw and needle position! 4 turns out is a lot different to the factory setting which is 1 1/2 turns out.

If it is overheating it is running too lean. As you changed the stator, also consider the ignition timing. Popping can also be caused by the ignition failing under load, coil, lead and spark plug.

Carburetor and tuning.

https://www.google.com/search?q=2004+yamaha+yfz+450+carburetor+adjustment

This carb has a LOT of jets!

https://www.amazon.ca/Carburetor-Rebuild-Yamaha-YFZ450-2004-2009/dp/B07JNYP667

....

The engine is not getting enough fuel. Try choking it some and see if this helps. If it does, then check the fuel filters. If you still have problems, then you will need to clean the carburetor or open the main jet if it is adjustable. Modern small engines are se to run as lean as possible to keep pollution down. This is much worse on small engines shipped to California. If the carburetor and filter are clean and you still have the problem, take the carburetor to lawn mower shop and see if they will replace the main jet with one a little larger.

Let me know if this gets you going. Robert

Hi Eugene, Anything is possible, knowing if it will work without causing damage is our real question. We need to determine the capacity of both engines and the jet sizes compatible with each respectively. If the jetting is too large the engine will run too rich, causing carbonisation and eventual poor performance. If the jetting is too small the result will be a lean very hot mixture, which can cause overheating of the combustion chamber and melt down damage to engine component parts. Something else that will affect performance is the matching of the Ventura tube or tubes onto the intake manifold. Each of the problems mentioned is easily overcome by simple examination and comparison. Keep in mind that I believe one of the most important settings in a carburetor is that of the float level. If it is too low the vehicle will suffer fuel starvation and if too high it will flood, causing stalling of the engine and difficulty in starting when hot. If your van uses points and condenser or electronic distributor, ignition timing should always be set before carrying out any adjustments to the carburation. By the way, what's wrong with the original carb? Regards John

Although blockages in the shroud and cooling fins are the most common cause of overheating, a small gas engine can also overheat if the fuel-air mix is too lean. Are you sure the carb overhaul kit had the right parts, and is there any possible of adjusting the mixture? Here is a set of parts diagrams for your tractor - Engine-2 has the carburetor-related parts. Good luck!

1. First check you carburetor manifolds for intake leak warm the engine up and spray WD40 all around the where the manifold connects to the heads if the rpms change when you do thins you have leak replace the gaskets.
2. Your carburetor may need cleaning due to a blocked or partially blocked low speed circuit.

Engine overheating on your Suzuki GSX1100E can be caused by these things: Engine oil level too low. Check the crankcase oil level.
Incorrect engine oil viscosity. Be sure to use the correct oil for the temperatures in your area.
Fuel-air mixture too lean. Caused by clogged carburetor jets from long term storage. Modifications to the air filter or air cleaner box will require carb re-jetting. Air leaks between the carbs and engine - check for lose clamps and cracked intake manifolds.
Incorrect ignition timing. Unlikely, but easy to check.
Damaged or extremely dirty oil cooler. Make sure there's nothing blocking air flow through the cooler.
Riding for extended periods at slow speeds - or idling the engine too long will cause insufficient air flow and overheating.
Finally, is it really overheating? Normal engine operating temperatures are pleanty hot enough to burn the skin if you touch most any part of the engine. Check the actual oil temperature. Anything above around 240F is cause for checking all of the items listed above.

Possible causes are:
Plugged up carburetors. Has the bike been sitting for a year or more? If so, then the carbs need to be disassembled and cleaned out. Moisture in the float bowls can cause this, too. Drain the float bowls.
Jetting too lean. Modifications to the exhaust system or air filter will require more fuel (larger jets).
Air leaks between the carburetors and the engine. Check for cracked intake manifolds or loose carburetors.
Low compression. Most likely cause is insufficient valve tappet clearance. Perform a complete engine tune up.

Bigger jetting (a higher fuel/air ratio) will not cause overheating. But an air leak between the engine and carburetor can cause overheating - and an erratic idle. Make sure the carb is correctly connected and there are no air leaks. An air leak could also be the cause of the popping that you were attempting to address by re-jetting.
Once any air leaks are corrected, adjust the idle mixture screw to attain the highest idle speed when the engine is at normal operating temperature. Then, use the idle speed screw to set the correct idle speed.
Finally, ride the bike at full throttle for a short time, pull the clutch and coast to a stop. Remove the spark plug and check the color; a tan or light brown color indicates correct jetting. Too light = too lean. Too dark = too rich.

Why?Most four strokes do like to get a little warm when just idling. But if it's real bad check your radiator fluid (of course) make sure its filled to the top of the fins, not to much over or it'll be overfilled. Then also look for air leaks. If there is a hole in your rubber piece leading from your air filter to your carburetor or anywhere where possible air can get into (and isnt suppose to) that'll heat up your engine to. If it tends to rev weirdly, like after twisting the throttle doesn't drop back down to idle quickly, then theres probably an air leak. One other thing is, check your jetting, if its set too lean then it could overheat to. this mainly is cause by after market parts (pipe mainly). To see if it's too lean, your muffler will have a sort of whiteish look on the inside of it. I'm not sure on what else to check. But if you do have an after market pipe, check with the makers to see if they have a recommended jet settings.,,,