grizzly 600 the timings right but still wont start?

Question

i rebuilt the motor on my friends bike.took awhile to get the timing right but now it wants to start but wont can anybody help me figure this out. what i cant under stand is that it has spark but wont kick over,,, please help me before i light it on fire....

Answer 1

which timing is right ignition timing, if its a 4 stroke engine the valve timing has to be right too.
if you are certain the ignition timing and valve is correct and you have a healthy spark you then need to see if the plugs are wet with fuel, if they are not then you need to check the fuel delivery to carbs, if thats ok then you need to see if the jets are blocked in the carbs, whch means stripping and cleaning them out with high air pressure.

if you already have fuel on the spark plug electrode and it wont start check the compression is ok by removing the plug and screwing in a compression tester if this is not available use your thumb over the hole and turn the bike over a few times if there is no compression then it is either damaged or you have incorrect valve timing. if you have compression and fuel at the plugs and a good spark then it has to be incorrect ignition timing you need to check the static timing if the bike has points this is easy to do and instructions will be in the manual. if it has no points then you will need to look if it is correct in the manual for your bike.

to sum it up for the engine to start you need correct valve and ignition timing, fuel reaching the cylinder, compression in the cylinder and a good spark. it would be easier to answer this question if you said what bike or at least what engine it is i.e. in line 4 cyl 4 stroke with dohc would suggest you did valve timing a tooth out on the cam chain,
hope this helps

Answer 2

Always give year, make, engine size and model # when asking questions. Some people don't know a Grizzly is a Yamaha quad.
Some of your future questions, we might have to know if it's a 2 or 4 wheel drive.
You just rebuilt the motor. Did you adjust the valves? Bring the piston to TDC of the compression stroke. If there is excessive valve clearance before adjusting them, you probably bent the valve. Then you'll have to do a leak down test.
Check that the carb is clean. Remove the pilot jet and hold it up to the light. You should be able to see through it.
Did you turn on the gas (open the petcock)? I know it's a stupid question. Even experienced mechanics will forget to turn on the gas after a motor job, at least one time in their career LOL