Is there a way to get gravel and motor oil out of a lawn mower engine?

My son has poured gravel and motor oil into our lawn boy mower...is there a way to save this mower?Is there a way to get gravel and motor oil out of a lawn mower engine?
It is a time consouming problem,but can be fixed.the bottom half of the moter is realy easy to get off.Just be careful not to tear any kind of gasket.Clen good and put back together.Replace fluids and start mowing.Is there a way to get gravel and motor oil out of a lawn mower engine?
remove and clean the parts affected, if worse comes to worse, tear it apart and rebuild the engine. If you haven't cranked it, just cleaning the gas tank and lines should do the trick (wipe out the carb on machine whilst your at it).
As asked before, did the gravel and oil go into the gas tank or the crankcase? If it is the fuel tank, remove it and wash it out. If it is the crankcase the engine will have to come apart. Remove the engine from the mower and seperate the the bottom case. You will probably need a new case gasket. Leaving any gravel in there will be bad.
My guess is he poured it into the fuel tank... If you haven't tried to start it, remove the fuel tank, dump it, wash it out and let it dry thoroughly. Remove the fuel line from the tank to the carburetor and clean it also. If you have already tried to start it, you will have to take the carburetor off and clean it also.