Has been sitting for a few years.. cleaned carb and chedcked settings on H and L screws.. still wont start.. replaced fuel lines and primer bulb.. and its a mac 3227 weedeater.. cranks but doesnt start, and cannot figure out the problem.. plz help

Press primer until fuel fills bulb and flows out carburetor. If no fuel in primer bulb then check connections.

Check fuel line connections by disconnecting retun line to tank (without filter) and pressing primer bulb. Fuel should draw from tank (filter), into bulb, out bulb to carb and expel out carburetor. If not the bad lines, filter, or lines not connected correctly.

With fuel primed, turn both high and low speed needles in (CW) until seated, do not tighten. Then turn needles out 1 1/2 turns for initial settings. These settings are only to get unit running. Increase idle speed setting if engine stalls. Adjust low speed, then high speed and lower idle speed back to normal.

primer or carb may get fuel to bowl but not into carb orifice to cylinder --primer failure induces air so no flow

new carbies start around $25.00 us on e-bay so get a new carby
take it to a mower shop for a service
rebuild the carby using a new carby kit

A few things can cause this. Clogged screen in carb and rotten fuel lines are the most common causes. Look inside the fuel tank. If the fuel line is stiff or discolored or if the filter has fallen off its time to replace the fuel lines. Check the fuel pump side of the carb and check the screen to see if its clogged. If the primer bulb is discolored ( any color but clear) its time to replace it. I suggest that if any one of these conditions exist to do it all at once... if the fuel lines are bad then the diaphrams are stiff, etc. Rebuild the carb and replace the fuel lines and primer bulb at the same time.
If you have just had any of the fuel lines off and the primer bulb wont pump then its possible the lines are reversed. If the primer is seperate from the carb; on the primer bulb there are two spigots, one short, and one long. The long one is output and goes to the tank, the short one is input and draws from the carb.

The bulb pulls fuel from the carb into the bulb and back to the tank, if the bulb does not fill it is because there is a fuel blockage, either in the fuel filter in the tank, or the screen in the carb itself.

hello sir, my machine will only start when pumping primmer bulb or squirting fluid in the carburetor than stops. the fuel line has broken off, in most small carburetors this is a ongoing problem.old fuel will crystallize when left in tank for a long time.plugging up ports, fuel lines, small screen in carburetor.fuel lines will dissolve clogging carb.this is why it will run when the choke is on creating a vacuum to where there is fuel forced in the carb to rum,also the gas will evaporate leaving the oil behind clogging up carb.the thing to do is remove carb. and clean out,replacing gaskets or fuel line if necessary.use carb cleaner to clean out carb.make sure to make note where fuel line go.the fuel filter broke off of fuel line letting debris get in carb plugging it up.the muffler is known to clog up a lot on these machines where they want run. the compression should be 60 to 120 lbs any thing below 60 is junk. when adjusting the carb screws turn in all the way than turnout 1 1/4 turns turn in slow until machine runs also you need to check for spark by removing plug and grounding against engine to check spark, ok.a new spark plug would be a good ideal too , if you are going to make these repairs use new fuel line and filter,hope this helps,any comments welcome,thank you, !!

Hi There, Check the primer bulb for tare or pin holes. Replace it. Check and clean carb jet it maybe plugged with debree. Also check for spark which you didn't say. Replace with correct plug.
Note; Do not use strong cleaners on rubber seals (O rings and gaskets) They dry up and crack.
If needed use a dabble of grease on seals

Who connected these hoses? the normal routing for a machine with a primer is like this, the fuel hose from the tank with the filter on the end goes to the carb fuel inlet nozzel ( not to the primer ) nearest to the pump cover ( cover on carb held with one screw ) the pipe from the metering side of the carb connects to the shorter nozzel on the primer bulb ( suction side ), the longer nozzel on the primer ( pressure side ) connects to the pipe going back to the tank, just remember the primer pulls fuel from the carb,into the bulb, and pushes it back into the tank, it is not actually a primer it is a purge. because it is connected this way it is impossible to flood the engine no matter how many times the bulb is pressed.
Let me know if it starts and runs.

This is an ongoing issue for users, and rightfully so. Small diameter line out of fuel tank (has filter in-tank on end) connects to the side of the carburetor that has the fuel pump....that is the cover without the hole in it. Other larger diameter fuel line out of tank connects to the longer nipple on the external purge/primer bulb. The bulb "pulls" fresh fuel from the fuel tank to the carb and then out of the carb to itself, where it then pushes any air/old fuel back into the fuel tank. The remaining larger diameter fuel line in this setup goes from the metering chamber (has cover with writing on it and a vent-hole) side of the carburetor to the smaller nipple on the purge/primer bulb. Years ago on 2-stroke trimmers, primers were not even used,...you choked the carb with a slide lever and gravity let fuel enter the carb from above...a few pulls, a "pop"...slide it off of choke and away you went.
If the purge/primer bulb is on top of the carb...small line from carb body to small hole in tank with filter. Larger diameter line goes from the bulb on the fuel pump side of the carb to the larger hole in the fuel tank where the line is held in place with a nylon nipple connector that keeps the line from pulling out of the tank.
Please vote on this solution.

Sometimes, its easy to miss a "hidden" screw. The plastic case probably has plastic guides for it they may even interlock together. Search again for a "hidden" screw before giving up. You will find more than just one fuel line. Here is how you would replace them if you choose to do so (recommended).
This is an ongoing issue for users, and rightfully so. Small diameter line out of fuel tank (has filter in-tank on end) connects to the side of the carburetor that has the fuel pump....that is the cover without the hole in it. Other larger diameter fuel line out of tank connects to the longer nipple on the external purge/primer bulb. The bulb "pulls" fresh fuel from the fuel tank to the carb and then out of the carb to itself, where it then pushes any air/old fuel back into the fuel tank. The remaining larger diameter fuel line in this setup goes from the metering chamber (has cover with writing on it and a vent-hole) side of the carburetor to the smaller nipple on the purge/primer bulb. Years ago on 2-stroke trimmers, primers were not even used,...you choked the carb with a slide lever and gravity let fuel enter the carb from above...a few pulls, a "pop"...slide it off of choke and away you went.
If the purge/primer bulb is on top of the carb...small line from carb body to small hole in tank with filter. Larger diameter line goes from the bulb on the fuel pump side of the carb to the larger hole in the fuel tank where the line is held in place with a nylon nipple connector that keeps the line from pulling out of the tank.