I have an 87 mojave. Wouldn't run unless choked. Cleaned the carb with no help so I took it to a local ATV mechanic. he cleaned the carb again and said that he thinks it's either a timing or ignition problem. it will start, but as soon as you touch the throttle, it bogs and stalls. Even if you spray eather in the carb's intake, it doesn't rev and higher and bogs. Any ideas?

 

Change the plug. If this doesn't work, check valve timing and clearances. Check the voltage at the battery with engine running, over 15v and it is overcharging. If you don't find a problem there, it may be time to try substitution, first the coil as it is cheapest, then CDI. Very rare for a CDI to work, but not properly, however I once had a Honda 300 that had the same symptoms. After swapping the plug and carb with no improvement, I tried a new CDI as I had one in stock, instant cure.