My engine is pulsing I removed the jet and cleaned with compressed air and cant figure out why it still surges at low rpm

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

It sounds like you either have a clogged nozzle or one that is too small for your pump. At lower speeds the pump is pumping less gpm. So your unloader valve does not cycle. Then when you go to full power. The engine is running faster and pumping more gallons per minute. The nozzle is too small or clogged and so the bypass opens and closes ( surges) Try a new nozzle that is the right size for your machine.

Try a new spark plug and then clean the
carb jets very carefully. Remove the jets
and blow out all the carb passageways.
The jets being plugged cause a lean fuel
mixture which causes the surging.
Last resort is check compression and do a
engine rebuild with new crankshaft seals.
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Sounds like low flow issue. Flush and clean system, PROPERLY! Buy a flush kit, drain system, blow compressed air through, fill with cleaner/water mix, run for 30 min with heat on, drain system, blow out with compressed air, fill with water, run for 30 min, drain, blow out with compressed air, fill with 60% coolant mix.

cold engine idle surge. (problem)
RPM range of surge not stated
300-700 or 800 to 1500? (range is critical to diagnosis)

bad fuel
running summer fuel in winter (running old fuel?)
needs a tune up bad, see the list in the operator guide.
idle speed controller,sticking or EGR valve same. (clean them)
location not stated, so cant guess about local air temps.?
no other symptoms, lack of engine power? etc?
was it ok last week, or better, when was the last time it was OK?
1week, 1year?
surge , causes, on a tuned engine might be:
1: too lean. so lean the ISC can not control idle. rpm low, stalling
2: too rich, flooding, stalling, spark plugs foul (look at them)
3: weak compression in 1 or more cylinders.
4: bad spark.
5: air leaks, in the plenum causing , ISC to lose control.
why high RPM?

especially?
well that means it fails hot too.
and there is a simple tests. for hot surge.
is engine fully hot? 180F and holds solid there?
say rpm is about 800
and you turn on head lights, heater fan and (not AC) and defrost.
the RPM must hold or the ISC is failing.
ISC -= idle speed controls. (all EFI has this function)

Surging or hunting as it is know is due to a fuel blockage in the carb, if the main jet is part blocked you need to clean it, remove the float bowl and blow out the jets with compressed air.

sounds like a air leak somewhere check the gaskets on the carburator

It would be best if the whole carburetor were soaked in carb cleaner and then blown out with compressed air. You could have a plugged up passageway in the carburetor. If you take this route and use comercially available carburetor cleaner, DO NOT put any rubber or plastic parts from your carb in the carb cleaner as it will ruin them. As for the jets, make sure you can see light through them. I usually take a strand of copper wire (like from stranded automotive electrical wire) and run it through the jets to make sure they are clean.
If this fails to correct the situation, check the engine's compression. Low compression will cause the engine to not run at low RPM. You need to see at least 140PSI of compression (throttle wide open) in order for the engine to idle. If the compression is low, adjust the valve tappet clearances. If this fails to bring the compression to a normal level, then the engine needs internal repairs.

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.

If it still surges after this unscrew the nut that holds the bowl This is the main jet, make sure hole (jet) is clean.

run the engine up no load screw it out untill the engine runs rich then slowly turn it back in untill it clears..then load it and do the same.

the arm is the govenor trying to play catch up this is normal.
tis is of corse that it has the mixture screw in the bowl..

If not remove the bowl locate the jet and clean it..