Small Engines (Lawn Mowers, etc.): kohler wont start, carbuerator, oil consumption

Question
QUESTION: I have a cv25 kohler engine I just rebuilt the engine and cannot get it started I did not remove the crank or cam to throw the engine out of time the problem is backfiring thru carbuerator and fire coming out of carb any ideas what could be wrong noticed spark looks weak thankyou

ANSWER: Len,

When you said you rebuilt the engine, was there a reason for doing the rebuild in the first place?  Was there some sort of underlying issue?  

It sounds like a timing issue to me, did you remove the flywheel?  If so there is a chance when you reinstalled it you did not torque the bolt correctly and the key sheared.  

you have hydraulic Valves so the adjustment should not be a problem...Are the valves seating properly?

Another item that may be giving you grief is your fuel solenoid?  Do you have a constant power supply to it?

See my video here to test the fuel solenoid  http://www.youtube.com/watch?v=w5zQjDhHdG0

Have you checked BOTH coils to make sure you are getting spark?

These are the areas I would be looking if I was troubleshooting this problem in the shop.

---------- FOLLOW-UP ----------

QUESTION: I rebuilt the engine due to high oil consumption and low compression never removed the flywheel there is plenty of fuel checked both plugs have spark how would the fuel solenoid cause this issue thankyou len

Answer
There are two diodes in the wire harness that if one is blown can cause the fuel solenoid to shut on and off, but the video i sent you is not the way to test this. u have to put an inline tester between the wire and solenoid. I merely sent the video as a future reference.

I am still thinking timing...Have you removed the bolt to check the key?  

you rebuilt the engine without removing the cam gear?  Are you sure it didnt accidently slip one tooth?  I would be double checking this as well.

just thinking out loud here...when you put the carb back on did the carb to intake  gasket slip and perhaps is covering part of the manifold?  Are you manifold gaskets properly in place where they mount to the head?

Please keep me updated...Im curious  u can email me directly at 4cycleengineguy@gmail.com