Crank shaft Seal keeps leaking for honda civic 1.7

SOURCE: oil leak on the rotor timing out put shaft

If you mean the camshaft seal, yes, you would need to pull the timing belt and sprocket off, and if you are anywhere near the service interval for the belt, replace it and the water pump (unless the water pump is very easy to service, and the tensioner.  
You will probably need a (gear/sprocket) puller to get the sprocket off and a another type of (seal) puller to get the seal out.  You could probably extract the old seal with a screwdriver, but it's not recommended.  Get a Haynes manual (around $20) before you even contemplate doing this youself. If you haven't done this before, are mechanically inclined. and have all the tools, you will spend about 1/2 a day to do either the cam seal by itself, or the seal, timing belt, tensioner and water pump.  Once you have it all apart, the last three components will only add an hour to the job, and you won't be stranded when the timing belt breaks.
good luck ..ajm

SOURCE: oil around spark plugs on 1992 honda accord

Yes the oil can cause the car to lose spark, the oil leak could be caused by the valve cover gaskets around the spark openings, but 9 times out of 10 it is the spark plug tube "O" rings. The top of the valve train comes off of the head, the "O" rings are between the two halves, that will fix the oil leak.

SOURCE: Honda s2000, 2001 loose of

Sounds like an ignition component failure check for proper resistance through primary and secondary ignition coil windings, refer to service repair manual for exact specs, also the ignitor magnetic pick up may be not up to snuff, the only other ignition component to replace or check is the ignition module and/or plug wires themselves, sometimes when extreme demand is put on the ignition system the plug wires must be high quality and completely isolated from one another. Spark plug wires when routing cannot come in contact with one another in the slightest proximity.

SOURCE: I have a oil leak ever since i bought this car.

NO if you have been using oil and loosing oil from all the seals and rocker cover and sump gasket then its caused by a thing called BACK PRESSURE,and that is caused by the piston rings worn, or broken top compression rings and a lip in the bore causing the ring gap to be about
6thou per inch causing the back pressure which in turn blowes oil out of all seals and gaskets ..
So take out the breather pipe from the rocker cover and let it blow into a paper towel for 2 minutes and if oil fumes come out the rings are worn.
Plus get a compression test on all cylinders and see if there down to 100 PSI or less.
The new head bolts should be replaced as they could be streached
threads, but not your problem this time
Let me know how you get on ASAP Ron

SOURCE: i have a 1989 honda accord dx with a oil pan

they don't use gaskets on oil sumps its sealant glue and yes u will have to reapply it when you put the sump back on, and what do u mean by main seal? do you mean the head gasket?