Runs good until hot chokes itself out or runs out of fuel engine reavs high then for 3 or 4 times then cuts off

didnt specify the make and model so generic answer ---check fuel mixture is correct --check the filter in tank is not plugging up--look for damaged / crack in fuel feed lines-look at spark plug --carb may need cleaning --exhaust port may need cleaning

My Harley is very slow to warm up, it also does not like to idle without choke unless it is good and warm. It could be the clogged filter was acting like a choke, but ruining your gas mileage. Now with air flowing smoothly the engine needs a bit of choke to idle. It should not need choke once it is fully warmed up unless your idle speed is set too low. With the engine hot, check RPM if you have a tach. If too low, adjust the idle speed at the carburetor. I suggest you find the adjustment while the engine is cold.

Hi John:
Sounds like it's too lean.
Try backing out the high speed screw 1/2 turn at a time until you don't need the choke. Then tune the high speed with saw running at full throttle. Screw in (lean) until RPM starts to drop, then back out 1/3 to 1/2 turn. Then set low speed at idle so engine is smooth but chain does not turn.

This sounds like a choke issue. Do you have a choke on that engine?

The purpose of a choke is to allow for a varying air:fuel ratio depending on how hot the engine is. A cool engine needs a more rich mixture of fuel to air. Once the engine warms up, it runs best with more air. The Choke is a mechanism that allows the operator to manually adjust this mixture. Generally, the choke is closed to start a cold engine, then is opened in 2 or 3 stages as the engine warms up. As the operator, as the engine starts to run smoothly, you would actuate the choke to the next notch, changing the fuel:air ratio so more air is mixed in with the fuel. It's probably best to give the engine a few minutes to warm up while you progress through the choke stages until it's fully open providing the best mixture for operation prior to beginning to clear the snow.

If you follow that process and the engine stalls when the choke is opened, then you need to clean your carburetor.

It should start easily, start with fresh fuel/oil, pump the primer as many times as it takes to 3/4 fill the bulb, pull the choke fully out, crank the engine until it fires once, push the choke fully in and crank again until it fires up, after re fueling a warm engine, pump the primer again until it 3/4 fills the bulb,before cranking the engine pull the choke fully out and in again( this will engage the part throttle ) then crank the engine until it fires up.

Hi there,

had the same problem before. What you need to do is to cancel out those basics that prevents the engine from running.

1. Check the spark plug, poor spark causes poor engine performance.
2. Poor fuel. Make sure no water is in the carburetor.
3. Idling problem or fuel-air mixture.

Quick Fixes:

1. Rev the engine with the choke ON. rev for at least 30 seconds to drive moisture out.
2. Drain the carburetor for any water deposits. This makes a bad mixture in the combustion.
3. Clean your spark plug.
4. Tune your Fuel-Air mixture to 2.5 turns out... Turn it clockwise until it stops and make 2.5 turns out. That's the standard.
5. Set your idle later if the engine's hot enough for idle run.

Your problem mostly is caused by poor fuel dispersion. Since pulling the choke entails less air and more fuel, it could be that that your engine requires more of it. If you have the time to remove the carburetor for disassembly, i recommended doing so. Remove the carb and clean the jets, make sure you put everything back in order.

That's it.. Let me know if there's any more problems... this is my usual approach.

I hope it helps,
levibit

Typically:
1. Press primer button 6-7 times until you see fuel flowing
2. Engage the choke lever to full choke /--/ pull cord 3-5 times until engine begins to start
3. Move choke lever to 1/2 choke and pull cord 2-3 times until engine starts - - allow to warm up (about 30 seconds) and move choke lever to no choke / / /
4. If engine does not start, repeat 1-3
If engine does not start, repost with more detail. Thanks! :)

You may need to replace the muffler,possibly it can't exhaust the fuel as fast as it is recieveing it.

2 or 4 barrel?
If auto choke, chk yhat for opening.
Msnifold vac fluctuating or thats just the range? Sounds a little high. neck time you start the motor, give the throttle a snap and vck the coke play position Cold running the choke should be 1/4 - 1/3 open. If you need info on how to adjust let me know Hot, or at operating temp, choke should be wide open. Good luck.

did you put back the choke (under fuel switch)
- and better rev once high in neutral after succesful start until engine gets warm