I recently rebuilt the top end of my 400 and according to the factory service manual when aligning the crank and cam sprockets that the crank should be on the (I) mark and the cam sprocket (I) mark should be in alignment with the case indicator. I did it this way and it won't run at all. If i align the (T) mark on crank and cam same as before it will start and run good up to half throttle and miss and back fire through carb. I have cleaned the carb twice thinking jets but still no fix. There are 3 marks on crank (I), (F), and (T) which is right to time engine. Please help. I am very confused:-)

 

the "T" mark is the on it stands for Top Dead Center. and the mark on the cam should inline with the indicator on the cylinder head. good luck

 

Thanks dude. I keep trying to get it right and the same result every time. Nothing past half throttle. I can't seem to get something right. I have never had this much trouble with an engine before. I keep wondering if it has something to do with the electronic ignition not advancing. I will keep trying and maybe something will work before i decide to set it on FIRE. Mud holes suck sometimes especially if you have no idea how deep they are before you sink to the handle bars. ( Start of all problems)