Do the BASICS!
Engines fail to start for MANY reasons and you REALLY should be able to start the diagnosis steps for yourself if you feel you are capabale of rebuilding an engine!
If you HAVE done these steps, why haven't you TOLD us?
Engines need thre basic things:
1) Fuel 2) Air 3) a spark! 4) Compression
after that comes:
5) Exhaust 6) more esoteric things like 'timing' etc.
Start with the EASIEST:-
However, note ONE safety rule! If you spin a motor with the plug out, you MUST ensure that a plug IS connected and is pressed against something that can 'earth' it! E.g, rest it ON the cylinder head! We have been told that NOT having that connection can damage the coil! There are arguments about if that is true or not but why find out the HARD way?????
Check the spark **************** Remove plug place on cyclinder head with plug lead CONNECTED Turn 'spin' the motor and look for spark If it DOESN'T have a spark..... guess where to start!
Then check for fuel ********************
Remove plug inspect plug, if it's 'wet' with fuel (i.e., wet with thin liquid and NOT covered with oil, then the FUEL is getting there or else it CAN'T be wet! Secondly, smell the plug, the plug hole and the exhasut, if the ALL smell of PETROL, then it MUST be getting there
If it DOESN'T smell of fuel...... guess where to start!
Check for Air *************
Remove plug Spin the motor and OPEN throttle during the spin. If the note is significantly different open/closed, then it's likely that the air IS passing through the engine. Need I say more?
Compression *************
Remove the plug Jam your finger over the plug hole and spin the motor. If you finger is FORCED off the hole, you have a fair amount of 'compression'. This will tell you if a valve is JAMMED open, a holed piston, broken con-rod etc.
Now, put the plug BACK and spin it again. Does the engine FEEL as though there is 'compression'?
***************
The lack of 'exhaust' (i.e., blocked exhaust, by a rag etc..... it's all TOO common in karts!) is a different problem. This usually will allow the engine fire but not to RUN!
So.......
Tell us the 'score' from the above tests and we'll have SOME hopes of helping you!
Ian
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