My kolher engine on my rototiller will not start.I can put a little bit of gas where the spark plug goes and it will start for a few seconds but won't keep running.is it major?

Troubleshooting Car That Won Start dummies or this link... Problem 5 Engine Cranks But won Start

Have you checked the fuel supply first. Its possible your jet valve may be plugged or dirt in the fuel bowl. One quick way of checking this is take the spark plug out and put a little shot of gas in the spark plug hole then reinstall the spark plug and put wire back in place and try to start engine. If it start and revs up for a few seconds till the gas is burnt up then stalls it is pretty certain its a dirty fuel jet or dirt in the fuel bowl. This quite often a real cheap fix .

Have you checked the fuel supply first. Its possible your jet valve may be plugged or dirt in the fuel bowl. One quick way of checking this is take the spark plug out and put a little shot of gas in the spark plug hole then reinstall the spark plug and put wire back in place and try to start engine. If it start and revs up for a few seconds till the gas is burnt up then stalls it is pretty certain its a dirty fuel jet or dirt in the fuel bowl. This quite often a real cheap fix .

Have you checked the fuel supply first. Its possible your jet valve may be plugged or dirt in the fuel bowl. One quick way of checking this is take the spark plug out and put a little shot of gas in the spark plug hole then reinstall the spark plug and put wire back in place and try to start engine. If it start and revs up for a few seconds till the gas is burnt up then stalls it is pretty certain its a dirty fuel jet or dirt in the fuel bowl. This quite often a real cheap fix .

If there is air in the tanks, it will be harder to crank, drain air out before starting, Also check spark plug. Sometimes i put gas where the plug goes, just a little pinch of gas though. put spark plug back and give it a few cranks.

First, you need to dump all of the fuel out of the gas tank, Preferrably into a gas container. If you know how much oil you dumped in, you can calculate how much more gas to add. You could also just dump the gas, re-mix some new gas and oil, whichever you prefer.

If you are comfortable doing this, remove the fuel lines going to the carberator and let them drain into a pan. Pump the fuel primer to purge the gas out of the carburator, and then re-install the fuel lines. This might help you get it started a little faster, but its not necessary. You can burn the old gas in the engine at it will be fine.

Next, remove and replace the spark plug. Its probably fowled out with too much oil. Keep a can of carb cleaner and a small wire brush handy, you may need to clean the spark plug a couple times. If it gets too dirty, you can replace the spark plug with a new one. Do not burn Carb Cleaner in your engine for long periods of time, it will damage the engine.

After you have installed the spark plug and put some correctly mixed gas in the tank, Try to start the engine again. There will be some residual fuel in the fuel lines going to the carberator, so you will need to burn off that gas.

If you can't get it to start, try these steps:
Choke off, throttle wide open, crank several times. (or let it sit in the sun for a couple hours) (this corrects flooding)
Prime carberatur, Choke full on, throddle idle position, crank until it fires once but does not start.
Choke half, crank until it fires again or starts.
If it starts skip this step: (Choke off, crank until it starts).
Keep the choke on half for about 10 seconds and let it idle.
Put the choke off and let the engine warm up for a couple minutes.
After warmup, test the throttle to see if it will run at full throttle (it may take some fluttering until the engine is fully warmed up)

Let the engine run at full throttle for a few minutes. The exhaust may be a little more blue-smokey than normal...this is the excess oil burning...totally normal and harmless.

check and make sure its getting fuel. when trying to start, spray some engine starting fluid in spark plug hole. just a little bit. replace the plug then try to start it. if it starts then quits then its a fuel problem. fuel not reaching engine. good-day !

Remove the plugs and see if there was an overflow. Now check the spark intensity with the plug connected. If this is low then check the coils and the LT trigger on the coil.
Make sure the spark gap is good , the plugs are clean and then check the carb for blocked jet.

Check for gas and spark. To check gas, turn on the key and listen for a wirring sound coming from the fuel tank for a few seconds indicating pressure is building up. To check spark, pull off a plug wire and place the end near the engine. Turning over the engine should produce a spark.

If you blow in the tank with your mouth it will put pressure on the fuel and force it through the lines and cause the carburetor to fill. You should then be able to start the engine.