Won't prime, the only way i start it is to remove spark plug and put fuel in cyl. I have replaced the primer bulb and line, and the fuel mixture is correct, My next step was to buy a new carb?

Flush old gas. Clean or replace spark plug. Check float on carb, clean carb bowl if equipped.

Does the engine run fine after it starts? Most common problem with primer bulb losing prime is an air leak in the fuel line or primer bulb. Air leaks don't always leak fuel. If there is an air leak between the primer bulb and gas tank there is no pressure, only vacuum. If it is not a major leak it might not leak without pressure but it will allow air to enter the fuel line. If it is a very minor air leak it could allow air to replace the liquid in the fuel line over time, but so little air once it is primer again that the fuel pump can over come it with volume of fuel.

Primer bulbs do not stay firm, as they are when initially pumped up, after the engine is running. There are check valves in the primer bulb that hold pressure in the primer bulb and throughout the fuel line to the engine. Once the engine starts the fuel pump creates vacuum drawing fuel into the engine diminishing this pressure and releasing the check valves. At this point the primer bulb is just another segment of fuel hose allowing fuel to pass through it as the fuel pump demands. The primer bulb functions much better when the outlet side is higher than the inlet side. This position makes it easier for the check valves in the primer bulb to seat and release as needed. If the primer bulb is functioning properly and is positioned with the outlet side higher than the inlet it should not be necessary to cover the end of the fuel hose with your thumb to get it to prime.

If the engine is hard to start after being fully primed there could be a problem with the fuel system on the engine. Some engines are hard to prime once air has entered the system, especially fuel injected models.

More information would be nice. How old is the cultivator? How long has it been since it last ran?
Possible causes for the primer bulb not to fill: 1. the bulb has a small hole in it (need to replace the primer bulb, usually a pretty easy job, just remove a couple of screws, remove the old bulb and install the new one). 2. One of the fuel lines may have a break or hole in it. If the cultivator is old enough a fuel line may have dry rotted and came apart.
A couple of things to try: Put fresh fuel in the tank then remove the air filter and put a few drops of fuel in the carburator then try to start the unit. If it starts an runs for a few seconds and dies the problem is the carb. is not getting fuel to the engine. If it still will not start check the spark plug. Is it fouled? Worn out or broken? If in doubt replace the plug.

replace spark plug.if spark plug okay problem could be carburetor or air leak at fuel lines or check primer bulb for crack which cause air leak.any breaks in fuel line or primer bulb cause air leaks fuel system cause carb not get fuel run engine.

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, !!

Make sure there are no leaks in the bulb. Did you reattach the fuel lijnes correctly? You should feel resistance after pushing 3 or 4 times to ensure fuel is getting to the carb. If necessary replace the bulb. Otherwise check with Mantis at www.mantis.com or give them a call for troubleshooting assistance.

Are you sure you have conected the pipes the correct way round, the fuel hose from the tank with the filter on the end goes to the main fuel inlet on the carb, nearest to the alloy pump cover, the other conection off the carb goes to the shorter conection on the back of the primer, the longer pipe on the primer goes back to the tank, just remember the primer pulls fuel from the carb, into the bulb, and back to the tank.

Sounds as though the fuel filter may be plugged. The filter is in the tank. Take a look, see if it is visible. Remove and replace. Good luck...Lee

replace the fuel filter and spark plug and if 2 stroke check fuel mixture

Hi

Priming the engine(put some gas in the sparkplug hole ,after you have checked the sparkplug,the colour of the spark has to be violet).Start the engine.If it starts there is a carburation problem,change the fuel lines to primer bulb.

wish you good luck savumihai71