Bike ran fine all day, turned off at favorite watering hole. came back out and the engine cranks fine but won't start. checked for spark by removing plug wire but did not get a spark, removed plug and checked again, no spark. tried another coil but same result. checked fuel, no problem. have worked back to ignition module. can this be tested?

Do you have fuel pressure and spark to the plugs ?

you CDI unit may have burned out or there's oil at the piston or there oil in the carborator

It is probably water has gotten into one of the sensors and needs be disconnected and dried out. the only way to distinguish which sensor is to have a tech connect a diagnostic meter to the vehicle.

If a starter is able to crank the engine but it won't start you usually have either an electrical or fuel problem. It's also remotely possibly that it's compression.If an engine has proper fuel, spark and compression, it will start when you crank it. So your challange is to find out which part isn't working right. Start with fuel. Spray a little starting fluid into the air intake while someone tries to start the engine. If it starts briefly when you're spraying starting fluid, you probably have a fuel delivery problem. That could be injectors, fuel pump, fuel filter, relay, fuse... who knows what until you check into it.If it doesn't start with starting fluid, check the spark. Pull a plug wire and attach it to a spare sparkplug and set the plug on a solid metal part of the engine. Have a helper crank the engine while you watch the plug. If you have a good spark, it might just be out of timing.In any case, you'll need to start isolating the problem. Find out which part isn't working then you'll know what to replace/repair.

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 !

When en engine won't start, there could be a number of things wrong. An engine requires air, fuel, and spark to start. You need to start by checking for spark. Take out one of the spark plugs and plug it back into the wire. Have somebody else turn the key while you hold the plug up to something metal on the engine, right next to the spark plug hole will be fine. You should see a bright blue spark, if you don't then you probably need to replace the spark plugs. You can do this same thing with any of the spark plugs. If you don't have spark on any of the plugs, get back with me and we'll go from there.

You didn't say what year and model the bike was but on any four stroke engine, you must have three things for the engine to run. You need fuel, spark, and compression. The easy one to check is the fuel. Take your air filter off and make sure you're getting fuel to the engine. Then, check your spark. Pull the spark plug wires off the spark plugs in the head and insert another set of plugs in the wires. Ground the plugs against the engine, turn the ignition switch on and press the start button. Watch the plugs to see if you have spark. The next test is compression. With the engine cold, remove the spark plugs. If you have a compression gauge, connect it to one of the heads and spin the engine over with the starter. If you don't have a gauge, simply put your finger over the spark plug hole. Turn the throttle wide open and press the start button. You should show about a hundred pounds of compression if you have a gauge or the compression should blow your finger off the hole with a good deal of force if you're checking it that way. If you have all three of these and they're timed correctly, the engine should run. If the engine won't run, find out which of the three elements is missing and work from there.

Good Luck
Steve

with 2 stroke engines there is 3 things that you need petrol air and spark if you have them the bike will run you say you have cleaned the carb have you checked the air box the filter could be blocked restricting the amount of air in also have you checked the spark plug remove it and see if you get a spark place the plug onto the engine so thats its touching some metal and try and strart the bike you should get a nice fat spark if you dont then replace the plug if you do have a look at it is it oily and black if so the the air screw on the carb needs turning 1/2 a turn inwards if its white then 1/2 turn out if it looks ok the check for compression place your finger over the hole in the engine where the plug came out and try and start the bike your finger should be pulled gently into the hole if not then the piston ring has either cracked or snapped and will need replacing
if all this is ok spray some easy start into the air box and kick the bke over it should start if it does then a new carb might be needed

hope this helps

John

The bike needs 3 things to run, fuel, compression and spark correctly timed. Try taking one plug out and connect it to the ignition lead. rest the plug against the engine and crank the bike - You should see a fat blue spark. If you have a spark, stick your finger down the plug hole where you removed the plug and crank again, there should be enough compression to blast you finger out. If you have all these, check the fuel filter

Your bike needs 4 things to run-Fuel, Spark, Air and Compression. One or some of these are missing.

1) Crank engine over several times to start. Remove spark plug. If plug is wet and smells like gas then it is getting fuel.

2) Check for spark
Put spark plug back into spark plug cap and lay spark end along side bolt or part of unpainted head making contact and crank over engine as if to start. If no spark then is electrical problem. Try changing spark plug. Check grounds. If not plug or grounds then purchase a shop manual from your local dealer and ohms test all electeical componet resistances as shop manual instructs. Be sure components do not meet specks before purchasing.

3) If has spark and plug was wet upon removal then gas has water or just old gas. If you drained the carb via bottom of carb screw into a clean clear container and see stuff at the bottom then carb is dirty with water and or dirt.

If your bike has been sitting along time condensation will build explaining water and or gas will loose its kick after sitting too long. If you think it has been sitting a long time it is best to dispose of old gas and refill with new. Water can also get into tank from gas can when fully tipped upright so dont dump every last drop into the tank...most ofter the last couple of cups are water.

If bike has been sitting for a few days and was running fine before that, turn off gas, drain carb via bottom of carb screw, close off screw and turn gas back on. This will refresh the gas in carb.

If none of these are the case and you have good fuel, good spark...check air filter for air flow. If all this is good then you need to do a compression check. A simple way to do it is to stick your finger in the spark plug hole and hold it in there with some force and have a friend try to start the bike. If it blows your finger out then it has compression. If it doesnt want to force your finger out then you have no compression and is a piston and ring problem. The only way to test compression for sure it to purchase a compression tester from auto parts store that has an adapter for your size plug hole and do a proper test. I hope this helps.